Communication methods and devices

Abstract

This application provides a method and apparatus for updating timing offsets, particularly applicable to NTN networks such as satellite communications. The method includes: a terminal device sending a third message to a network device based on a first timing offset; wherein the first timing offset indicates the degree of delay in sending the third message by the terminal device, and the third message includes indication information indicating a second timing offset, which is the updated first timing offset; and the terminal device sending a fifth message to the network device based on the second timing offset. This method can update the timing offset promptly and effectively while ensuring that the terminal device has sufficient time to make timing adjustments in advance, avoiding the waste of time and frequency resources.

Description

[0001] This application is a divisional application. The original application has the application number 202011105437.3 and the original application date is October 15, 2020. The entire contents of the original application are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a method and apparatus for updating timing offsets. Background Technology

[0003] Currently, New Radio (NR) technology has moved from the standardization stage to the commercial deployment stage. The NR standard was designed for terrestrial communication. Compared to terrestrial communication, non-terrestrial networks (NTN) communication has the advantages of large coverage area and flexible networking.

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

[0005] Generally, to ensure that the base station receives the uplink signal sent by the terminal device within a specified time, the terminal device needs to make timing adjustments in advance before sending the uplink signal. However, based on the uplink and downlink timing relationship, the amount of timing adjustments that the terminal device can make in advance is far less than 13ms.

[0006] Therefore, how to ensure that terminal devices have sufficient time to make timely adjustments in advance is a problem that needs to be solved. Summary of the Invention

[0007] This application provides a method and apparatus for updating timing offset, which updates the timing offset in a timely and effective manner while ensuring that the terminal device has enough time to make timing adjustments in advance, thus avoiding the waste of time and frequency resources.

[0008] Firstly, this application provides a method for updating a timing offset, the method comprising:

[0009] The terminal device sends a third message to the network device according to a first timing offset; wherein, the first timing offset is used to indicate the degree of delay in the terminal device sending the third message, and the third message includes indication information, the indication information being used to indicate a second timing offset, the second timing offset being an updated first timing offset;

[0010] The terminal device sends a fifth message to the network device according to the second timing offset.

[0011] The technical solution provided in this application has two advantages: firstly, by setting a timing offset, the terminal device has sufficient time to make timing adjustments in advance; secondly, by updating the timing offset, the terminal device can use the appropriate timing offset in a timely manner. Compared to not updating the timing offset, the embodiments of this application, while ensuring that the terminal device has sufficient time to make timing adjustments in advance, can also reduce end-to-end latency and avoid resource waste.

[0012] In one possible implementation, before the terminal device sends a third message to the network device according to a first timing offset, the method further includes: the terminal device sending a first message to the network device, the first message including a random access preamble; the terminal device receiving a second message sent by the network device, the second message including a random access response message; and after the terminal device sends the third message to the network device according to the first timing offset, the method further includes: the terminal device receiving a fourth message sent by the network device, the fourth message including a random access contention resolution message.

[0013] In this embodiment of the application, the first message can be understood as Msg1 in the four-step random access process, the second message can be understood as Msg2 in the four-step random access process, the third message can be understood as Msg3 in the four-step random access process, and the fourth message can be understood as Msg4 in the four-step random access process.

[0014] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the second timing offset.

[0015] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes a first set of adjustment parameters, the first set of adjustment parameters being used to determine the second timing offset.

[0016] In this embodiment, the number of bits used by the terminal device when sending the first set of adjustment parameters is much smaller than the number of bits used when directly sending the second timing offset, thus saving signaling overhead.

[0017] In one possible implementation, the first set of adjustment parameters includes any one or more of the following:

[0018] The parameters are determined based on the delay start duration of the random access response (RAR) receive window and the duration of the RAR receive window; or based on the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or based on the common timing advance; or based on the orbital altitude of the network device; or based on the round-trip delay between the terminal device and the network device.

[0019] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the amount of change between the second timing offset and the reference timing offset.

[0020] In this application, the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0021] In one possible implementation, the fourth message includes the second timing offset; or,

[0022] The fourth message includes the change between the second timing offset and the reference timing offset; wherein the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0023] In one possible implementation, the method further includes:

[0024] The terminal device receives an activation information sent by the network device, the activation information indicating the activation time of the second timing offset; or the terminal device sends an activation information to the network device, the activation information indicating the activation time of the second timing offset; or the second timing offset becomes effective m time slots after the terminal device sends the third message, where m is a pre-set integer; or the second timing offset becomes effective n time slots after the terminal device receives the fourth message, where n is a pre-set integer.

[0025] In one possible implementation, before the terminal device sends a third message to the network device according to a timing offset, the method further includes: the terminal device receiving a broadcast message sent by the network device; wherein the broadcast message includes any one or more of the following: the delay start duration of the RAR receive window and the duration of the RAR receive window; or

[0026] The delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or

[0027] The common timing advance; or the orbital altitude of the network device.

[0028] In one possible implementation, when the broadcast message includes the delay start duration of the RAR receiving window and the duration of the RAR receiving window, the first timing offset satisfies the following condition:

[0029]

[0030] Wherein, K offset The value of the first timing offset; the duration of the RAR receiving window, which represents the duration for which the terminal device receives the RAR; the delay start duration of the RAR receiving window, which represents the delay duration for which the terminal device opens the RAR receiving window after sending the first message; the slot_duration is the unit of duration; the ΔK offset The time offset difference, △K offset It is an integer.

[0031] In one possible implementation, when the broadcast message includes the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer, the first timing offset satisfies the following condition:

[0032]

[0033] Wherein, RCR_timer is the duration of the random access contention resolution timer, which represents the maximum allowed time interval between the start of the random access contention resolution timer after the terminal device sends the third message and the receipt of the fourth message; RCR_offset is the delay start duration of the random access contention resolution timer, which represents the delay duration for the terminal device to start the random access contention resolution timer after sending the third message; slot_duration is the unit of duration; △K offset The time offset difference, △K offset It is an integer.

[0034] In one possible implementation, the fifth message includes any one of data information, feedback message, or sounding reference signal (SRS).

[0035] Optionally, the feedback message includes the feedback message of the fourth message.

[0036] In one possible implementation, the method further includes: the terminal device receiving a timing advance adjustment instruction sent by the network device, the timing advance adjustment instruction being used to indicate updating the second timing offset; 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.

[0037] In one possible implementation, the method further includes: when one or more of the following conditions are met, the terminal device receives an updated second timing offset or a change between the updated second timing offset and the reference timing offset sent by the network device; wherein one or more of the following conditions include: the terminal device switching cells; or the terminal device switching beams; or the terminal device switching a portion of the bandwidth (BWP).

[0038] Secondly, this application provides a method for updating a timing offset, characterized in that the method includes:

[0039] The network device receives a third message sent by the terminal device according to a first timing offset; wherein the first timing offset is used to indicate the degree of delay in the network device receiving the third message; and the third message includes indication information, the indication information being used to indicate a second timing offset, the second timing offset being an updated first timing offset; the network device receives a fifth message sent by the terminal device.

[0040] In one possible implementation, before the network device receives the third message sent by the terminal device according to the first timing offset, the method further includes: the network device receiving a first message sent by the terminal device, the first message including a random access preamble; the network device sending a second message to the terminal device, the second message including a random access response message; after the network device receives the third message sent by the terminal device according to the first timing offset, the method further includes: the network device sending a fourth message to the terminal device, the fourth message including a random access contention resolution message.

[0041] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the second timing offset.

[0042] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes a first set of adjustment parameters, the first set of adjustment parameters being used to determine the second timing offset.

[0043] In one possible implementation, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the delay start duration of the random access response (RAR) receive window and the duration of the RAR receive window; or parameters determined based on the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or

[0044] The parameters are determined based on the common timing advance; or based on the orbital altitude of the network device; or based on the round-trip delay between the terminal device and the network device.

[0045] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the amount of change between the second timing offset and the reference timing offset.

[0046] In this application, the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0047] In one possible implementation, the fourth message includes the second timing offset; or, the fourth message includes a change based on the second timing offset and a reference timing offset; wherein the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0048] In one possible implementation, the method further includes: the network device sending activation information to the terminal device, the activation information indicating the activation time of the second timing offset; or the network device receiving activation information sent by the terminal device, the activation information indicating the activation time of the second timing offset; or the second timing offset becoming effective m time slots after the network device receives the third message, where m is a pre-set integer; or the second timing offset becoming effective n time slots after the network device sends the fourth message, where n is a pre-set integer.

[0049] In one possible implementation, before the network device receives the third message sent by the terminal device according to the first timing offset, the method further includes: the network device sending a broadcast message; wherein the broadcast message includes any one or more of the following: the delay start duration of the RAR receive window and the duration of the RAR receive window; or the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or the common timing advance; or the orbital altitude of the network device.

[0050] In one possible implementation, when the broadcast message includes the delay start duration of the RAR receiving window and the duration of the RAR receiving window, the first timing offset satisfies the following condition:

[0051]

[0052] Wherein, K offse1t The value of the first timing offset; the duration of the RAR receiving window, which represents the duration for which the terminal device receives the RAR; the delay start duration of the RAR receiving window, which represents the delay duration for which the terminal device opens the RAR receiving window after sending the first message; the slot_duration is the unit of duration; the ΔK offset The time offset difference, △K offset It is an integer.

[0053] In one possible implementation, when the broadcast message includes the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer, the first timing offset satisfies the following condition:

[0054]

[0055] Wherein, K offse1tThe value of the first timing offset; the duration of the RCR_timer is the duration of the random access contention resolution timer, which represents the maximum allowed time interval between the start of the random access contention resolution timer after the terminal device sends the third message and the receipt of the fourth message; the RCR_offset is the delay start duration of the random access contention resolution timer, which represents the delay duration for the terminal device to start the random access contention resolution timer after sending the third message; the slot_duration is the unit of duration; the △K offset The time offset difference, △K offset It is an integer.

[0056] In one possible implementation, the fifth message includes any one of data information, feedback message, or probe reference signal (SRS).

[0057] In one possible implementation, the method further includes: the network device sending a timing advance adjustment instruction to the terminal device, the timing advance adjustment instruction being used to indicate updating the second timing offset; the network device receiving the updated second timing offset or a second adjustment parameter set sent by the terminal device, the second adjustment parameter set being used to determine the updated second timing offset.

[0058] In one possible implementation, the method further includes: when one or more of the following conditions are met, the network device sends an updated second timing offset or a change based on the updated second timing offset and the reference timing offset to the terminal device; wherein one or more of the conditions include: the terminal device switching cells; or the terminal device switching beams; or the terminal device switching partial bandwidth (BWP).

[0059] The beneficial effects in the second aspect can be found in the beneficial effects in the first aspect, and will not be repeated here.

[0060] Thirdly, this application provides a communication device, the device comprising:

[0061] A processing unit is configured to generate a third message; the third message includes indication information, the indication 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 the degree of delay in the communication device sending the third message; a sending unit is configured to send the third message to a network device according to the first timing offset; the sending unit is further configured to send a fifth message to the network device according to the second timing offset.

[0062] In one possible implementation, the sending unit is further configured to send a first message to the network device, the first message including a random access preamble; the receiving unit is further configured to receive a second message sent by the network device, the second message including a random access response message; and the receiving unit is further configured to receive a fourth message sent by the network device, the fourth message including a random access contention resolution message.

[0063] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the second timing offset.

[0064] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes a first set of adjustment parameters, the first set of adjustment parameters being used to determine the second timing offset.

[0065] In one possible implementation, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the delay start duration of the random access response (RAR) receive window and the duration of the RAR receive window; or parameters determined based on the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or

[0066] The parameters are determined based on the common timing advance; or based on the orbital altitude of the network device; or based on the round-trip delay between the communication device and the network device.

[0067] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the amount of change 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 one possible implementation, the fourth message includes the second timing offset; or, the fourth message includes a change based on the second timing offset and a reference timing offset; wherein the reference timing offset is the timing offset currently used by the communication device or a preset timing offset.

[0070] In one possible implementation, the receiving unit is further configured to receive activation information sent by the network device, the activation information indicating the activation time of the second timing offset; or the sending unit is further configured to send activation information to the network device, the activation information indicating the activation time of the second timing offset; or the second timing offset becomes effective m time slots after the communication device sends the third message, where m is a pre-set integer; or the second timing offset becomes effective n time slots after the communication device receives the fourth message, where n is a pre-set integer.

[0071] In one possible implementation, the receiving unit is further configured to receive a broadcast message sent by the network device; wherein the broadcast message includes any one or more of the following: the delay start duration of the RAR receive window and the duration of the RAR receive window; or the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or the common timing advance; or the orbital altitude of the network device.

[0072] In one possible implementation, when the broadcast message includes the delay start duration of the RAR receiving window and the duration of the RAR receiving window, the first timing offset satisfies the following condition:

[0073]

[0074] Wherein, K offset1 The value of the first timing offset; the RAR_window is the duration of the RAR receiving window, which represents the duration for which the communication device receives the RAR; the RAR_offset is the delay start duration of the RAR receiving window, which represents the delay duration for which the communication device opens the RAR receiving window after sending the first message; the slot_duration is the unit of duration; the △K offset The time offset difference, △K offset It is an integer.

[0075] In one possible implementation, when the broadcast message includes the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer, the first timing offset satisfies the following condition:

[0076]

[0077] Wherein, K offse1tThe value of the first timing offset; the duration of the RCR_timer is the duration of the random access contention resolution timer, which represents the maximum allowed time interval between the start of the random access contention resolution timer after the communication device sends the third message and the receipt of the fourth message; the RCR_offset is the delay start duration of the random access contention resolution timer, which represents the delay duration for the communication device to start the random access contention resolution timer after sending the third message; the slot_duration is the unit of duration; the △K offset The time offset difference, △K offset It is an integer.

[0078] In one possible implementation, the fifth message includes any one of data information, feedback message, or probe reference signal (SRS).

[0079] In one possible implementation, the receiving unit is further configured to receive a timing advance adjustment instruction sent by the network device, the timing advance adjustment instruction being used to indicate an update of 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, the second adjustment parameter set being used to determine the updated second timing offset.

[0080] In one possible implementation, the receiving unit is further configured to receive an updated second timing offset or a change between the updated second timing offset and the reference timing offset sent by the network device when any one or more of the following conditions are met; wherein any one or more of the conditions include: the communication device switching cells; or the communication device switching beams; or the communication device switching partial bandwidth (BWP).

[0081] Fourthly, this application provides a communication device, the device comprising:

[0082] The receiving unit is configured to receive a third message sent by a terminal device according to a first timing offset; wherein the first timing offset is used to indicate the degree of delay in the network device receiving the third message; and the third message includes indication information, the indication information being used to indicate a second timing offset, the second timing offset being an updated first timing offset; the receiving unit is further configured to receive a fifth message sent by the terminal device.

[0083] In one possible implementation, the apparatus further includes a sending unit; wherein the receiving unit is configured to receive a first message sent by the terminal device, the first message including a random access preamble; the sending unit is configured to send a second message to the terminal device, the second message including a random access response message; the sending unit is further configured to send a fourth message to the terminal device, the fourth message including a random access contention resolution message.

[0084] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the second timing offset.

[0085] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes a first set of adjustment parameters, the first set of adjustment parameters being used to determine the second timing offset.

[0086] In one possible implementation, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the delay start duration of the random access response (RAR) receive window and the duration of the RAR receive window; or parameters determined based on the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or

[0087] The parameters are determined based on the common timing advance; or based on the orbital altitude of the communication device; or based on the round-trip delay between the terminal device and the communication device.

[0088] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the amount of change between the second timing offset and the reference timing offset.

[0089] In this application, the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0090] In one possible implementation, the fourth message includes the second timing offset; or, the fourth message includes a change based on the second timing offset and a reference timing offset; wherein the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0091] In one possible implementation, the sending unit is further configured to send activation information to the terminal device, the activation information indicating the activation time of the second timing offset; or the receiving unit is further configured to receive activation information sent by the terminal device, the activation information indicating the activation time of the second timing offset; or the second timing offset becomes effective m time slots after the communication device receives the third message, where m is a pre-set integer; or the second timing offset becomes effective n time slots after the communication device sends the fourth message, where n is a pre-set integer.

[0092] In one possible implementation, the transmitting unit is further configured to transmit a broadcast message; wherein the broadcast message includes any one or more of the following: the delay start duration of the RAR receive window and the duration of the RAR receive window; or the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or the common timing advance; or the orbital altitude of the communication device.

[0093] In one possible implementation, when the broadcast message includes the delay start duration of the RAR receiving window and the duration of the RAR receiving window, the first timing offset satisfies the following condition:

[0094]

[0095] Wherein, K offset1 The value of the first timing offset; the duration of the RAR receiving window, which represents the duration for which the terminal device receives the RAR; the delay start duration of the RAR receiving window, which represents the delay duration for which the terminal device opens the RAR receiving window after sending the first message; the slot_duration is the unit of duration; the ΔK offset The time offset difference, △K offset It is an integer.

[0096] In one possible implementation, when the broadcast message includes the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer, the first timing offset satisfies the following condition:

[0097]

[0098] Wherein, K offset1The value of the first timing offset; the duration of the RCR_timer is the duration of the random access contention resolution timer, which represents the maximum time between the start of the random access contention resolution timer after the terminal device sends the third message and the receipt of the fourth message; the RCR_offset is the delay start duration of the random access contention resolution timer, which represents the delay duration for the terminal device to start the random access contention resolution timer after sending the third message; the slot_duration is the unit of duration; the △K offset The time offset difference, △K offset It is an integer.

[0099] In one possible implementation, the fifth message includes any one of data information, feedback message, or probe reference signal (SRS).

[0100] In one possible implementation, the sending unit is further configured to send a timing advance adjustment instruction to the terminal device, the timing advance adjustment instruction being used to indicate the updating of the second timing offset; the receiving unit is further configured to receive the updated second timing offset or the second adjustment parameter set sent by the terminal device, the second adjustment parameter set being used to determine the updated second timing offset.

[0101] In one possible implementation, the transmitting unit is further configured to transmit an updated second timing offset or a change between the updated second timing offset and the reference timing offset to the terminal device when any one or more of the following conditions are met; wherein any one or more of the conditions include: the terminal device switching cells; or the terminal device switching beams; or the terminal device switching partial bandwidth (BWP).

[0102] Fifthly, this application provides a communication device including a processor, which, when executing a computer program or instructions in a memory, performs the method described in the first aspect.

[0103] In a sixth aspect, this application provides a communication device including a processor, wherein the method described in the second aspect is executed when the processor invokes a computer program or instructions in memory.

[0104] In a seventh aspect, this application provides a communication device, the communication device including a processor and a memory, the memory being used to store computer execution instructions; the processor being used to execute the computer execution instructions stored in the memory to cause the communication device to perform the method as described in the first aspect.

[0105] Eighthly, this application provides a communication device, the communication device including a processor and a memory, the memory being used to store computer execution instructions; the processor being used to execute the computer execution instructions stored in the memory to cause the communication device to perform the method as described in the second aspect.

[0106] Ninthly, this application provides a communication device, the communication device including a processor, a memory, and a transceiver, the transceiver being used to receive or transmit signals; the memory being used to store program code; and the processor being used to execute the program code to cause the communication device to perform the method as described in the first aspect.

[0107] In a tenth aspect, this application provides a communication device, the communication device including a processor, a memory, and a transceiver, the transceiver being used to receive or transmit signals; the memory being used to store program code; and the processor being used to execute the program code to cause the communication device to perform the method as described in the second aspect.

[0108] Eleventhly, this application provides a communication device, the communication device including a processor and an interface circuit, the interface circuit being configured to receive code instructions and transmit them to the processor; the processor executing the code instructions to cause the method as shown in the first aspect to be performed.

[0109] In a twelfth aspect, this application provides a communication device comprising a processor and an interface circuit, the interface circuit being configured to receive code instructions and transmit them to the processor; the processor executing the code instructions to cause the method as shown in the second aspect to be performed.

[0110] In a thirteenth aspect, this application provides a computer-readable storage medium for storing instructions or a computer program that, when executed, cause the method described in the first aspect to be implemented.

[0111] In a fourteenth aspect, this application provides a computer-readable storage medium for storing instructions or a computer program that, when executed, causes the method described in the second aspect to be implemented.

[0112] In a fifteenth aspect, this application provides a computer program product comprising instructions or a computer program that, when executed, causes the method described in the first aspect to be implemented.

[0113] In a sixteenth aspect, this application provides a computer program product comprising instructions or a computer program that, when executed, causes the method described in the second aspect to be implemented.

[0114] In a seventeenth aspect, this application provides a computer program for performing the method described in the first aspect.

[0115] In an eighteenth aspect, this application provides a computer program for performing the method described in the second aspect.

[0116] In a nineteenth aspect, this application provides a communication system including a terminal device and a network device, wherein the terminal device is configured to perform the method described in the first aspect, and the network device is configured to perform the method described in the second aspect. Attached Figure Description

[0117] Figure 1 This is a schematic diagram of the architecture of an NTN communication system provided in an embodiment of this application;

[0118] Figure 2 This is a schematic diagram illustrating the relationship between round-trip time delay and minimum elevation angle provided in an embodiment of this application;

[0119] Figure 3 This is a schematic diagram of the architecture of an NTN communication system provided in an embodiment of this application;

[0120] Figure 4 This is a flowchart illustrating a four-step random access method provided in an embodiment of this application;

[0121] Figure 5a This is a schematic diagram illustrating the relationship between timing advance and signal provided in an embodiment of this application;

[0122] Figure 5b This is a schematic diagram illustrating the relationship between timing advance and signal provided in an embodiment of this application;

[0123] Figure 5c This is a schematic diagram illustrating the relationship between timing advance and signal provided in an embodiment of this application;

[0124] Figure 6 This is a schematic flowchart of a method for updating timing offset provided in an embodiment of this application;

[0125] Figure 7a This is a schematic diagram illustrating the relationship between timing advance and signal provided in an embodiment of this application;

[0126] Figure 7b This is a schematic diagram illustrating the relationship between timing advance and signal provided in an embodiment of this application;

[0127] Figure 8a This is a schematic diagram of the reference angle between a service link and a power supply link provided in an embodiment of this application;

[0128] Figure 8b This is a schematic diagram illustrating the relationship between the maximum round-trip time delay difference and the minimum elevation angle provided in an embodiment of this application;

[0129] Figure 9 This is a schematic diagram illustrating the relationship between m and effective time, provided in an embodiment of this application.

[0130] Figure 10a This is a schematic flowchart of a method for updating timing offset provided in an embodiment of this application;

[0131] Figure 10b This is a schematic flowchart of a method for updating timing offset provided in an embodiment of this application;

[0132] Figure 11 This is a flowchart illustrating a two-step random access method provided in an embodiment of this application;

[0133] Figure 12 This is a schematic flowchart of a method for updating timing offset provided in an embodiment of this application;

[0134] Figure 13 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0135] Figure 14 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0136] Figure 15 This is a schematic diagram of an NTN communication system based on a reference point, provided in an embodiment of this application;

[0137] Figure 16 This is a diagram of an NTN system architecture based on replacing Koffset values ​​with reference point coordinates, provided in an embodiment of this application.

[0138] Figure 17 This is a schematic diagram A of a Koffset value / Koffset reference point coordinate indicator provided in an embodiment of this application;

[0139] Figure 18 This is a schematic diagram (B) of a Koffset value / Koffset reference point coordinate indicator provided in an embodiment of this application;

[0140] Figure 19 This is a schematic diagram of a Koffset angle provided in an embodiment of this application;

[0141] Figure 20 This is a schematic diagram illustrating the relationship between signaling and time slots provided in an embodiment of this application;

[0142] Figure 21 This is a schematic diagram illustrating the relationship between signaling and time slots provided in an embodiment of this application. Detailed Implementation

[0143] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover 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 steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0144] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0145] In this application, "at least one (item)" means one or more, "more than one" means two or more, "at least two (items)" means two or three or more, and "and / or" is used to describe the relationship between related objects, indicating that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0146] The embodiments of this application will now be described with reference to the accompanying drawings.

[0147] The method provided in this application can be applied to NTN communication systems, such as... Figure 3 As shown, the communication system can consist of terminal equipment, satellites (or satellite base stations) and ground stations (or gateway stations).

[0148] Terminal equipment, also known as user equipment (UE) or terminal, is a device with wireless transceiver capabilities. It can be deployed on land (indoors or outdoors, handheld, wearable, or vehicle-mounted), on water (e.g., on ships), or in the air (e.g., on airplanes, balloons, or satellites). Terminal equipment can be mobile phones, tablets, computers with wireless transceiver capabilities, virtual reality (VR) terminals, augmented reality (AR) terminals, wireless terminals in industrial control, self-driving, remote medical care, smart grids, transportation safety, smart cities, smart homes, and so on. It can also be understood that this terminal equipment could be used in future 5G networks or future evolved public land mobile networks (PLMNs). For ease of description, the following will use the UE as an example to illustrate the method involved in the embodiments of this application.

[0149] Optional, Figure 3 In the communication system shown, terminal devices can communicate with each other through communication technologies such as device-to-device (D2D), vehicle-to-everything (V2X), or machine-to-machine (M2M). This application does not limit the communication method between terminal devices.

[0150] In this application, satellites can provide wireless access services to terminal devices, allocate wireless resources to accessing terminal devices, and provide reliable wireless transmission protocols and data encryption protocols. Satellites can be artificial Earth satellites or high-altitude spacecraft used as wireless communication base stations, such as evolved NodeBs (eNBs) and 5G base stations (gNBs). Alternatively, satellites can act as relays for these base stations, transmitting their wireless signals to terminal devices; in this case, the ground station can be considered a wireless communication base station. Therefore, in some embodiments of this application, such as in satellite regeneration scenarios, the network device can be... Figure 3The satellite base station shown; in other embodiments, such as in a satellite pass-through scenario, the network device can be... Figure 3 The ground station is shown. Therefore, for ease of description, the method involved in this application will be illustrated below using a network device as a base station as an example.

[0151] In this embodiment, the network device may include, but is not limited to, the base station shown above. For example, the base station may also be a base station in a future communication system such as a sixth-generation communication system. Optionally, the network device may also be an access node, wireless relay node, or wireless backhaul node in a wireless local area network (WiFi) system. Optionally, the network device may also be a wireless controller in a cloud radio access network (CRAN) scenario. Optionally, the network device may also be a wearable device or an in-vehicle device. Optionally, the network device may also be a small cell, a transmission reception point (TRP) (or a transmission receiving point), etc. It is understood that the network device may also be a base station in a future PLMN, etc.

[0152] Optionally, the satellite can be a geostationary earth orbit (GEO) satellite, a non-geostationary earth orbit (NGEO) medium earth orbit (MEO) satellite or a low earth orbit (LEO) satellite, or a High Altitude Platform Station (HAPS), etc.

[0153] Ground stations can be used to connect satellites and the core network. For example, when a satellite acts as a base station for wireless communication, the ground station can transmit signaling between the satellite and the core network. Alternatively, the ground station can act as a base station for wireless communication, and the satellite can transmit signaling between the terminal device and the ground station. For instance, during communication, the ground station can send signaling from the core network to the satellite via a feedback link (or feeder link); and the satellite can then send the signaling to the terminal device via a service link between the satellite and the terminal device. Correspondingly, the terminal device can also send signaling to the satellite via the service link, and the satellite can then send the signaling to the core network via the ground station.

[0154] Understandable Figure 3Only one satellite and one ground station are shown. In actual use, a multi-satellite and / or multi-ground-station architecture can be adopted as needed. Each satellite can provide services to one or more terminal devices, each satellite can correspond to one or more ground stations, and each ground station can correspond to one or more satellites, etc., which are not specifically limited in this application.

[0155] To fully understand the method shown in this application, the four-step random access method involved in the embodiments of this application is described in detail below. For example... Figure 4 As shown:

[0156] 401. The UE sends a random access preamble, also known as the first message (Msg1), to the base station. The purpose of the random access preamble is to notify the base station that there is a random access request and to enable the base station to estimate the transmission delay between itself and the UE. This allows the base station to calibrate the uplink timing and inform the UE of the calibration information through a timing advance (TA) command.

[0157] 402. After detecting the random access preamble, the base station sends a random access response (RAR) to the UE, also known as the second message (Msg2). The random access response may include the sequence number of the random access preamble received in 401 above, the timing advance command, uplink resource allocation information, and the temporary cell-radionetwork temporary identifier (TC-RNTI), etc.

[0158] 403. When a UE receives a random access response, if the sequence number of the random access preamble in the response indicates the same random access preamble as the one sent by the UE to the base station in 401 above, the UE considers the random access response to be a response specifically for that UE, meaning the UE has received the random access response for that UE. After receiving the random access response, the UE sends an uplink message on the uplink resources indicated by the response, such as uplink data on the Physical Uplink Shared Channel (PUSCH), also known as the third message (Msg3). Msg3 may carry a unique user identifier.

[0159] 404. When the base station receives the uplink message from the UE, it returns a conflict resolution message, also known as the fourth message (Msg4), to the UE that has successfully accessed the network. The base station will carry the unique user identifier from Msg3 in the conflict resolution message to indicate the UE that has successfully accessed the network, while other UEs that have not successfully accessed the network will re-initiate random access.

[0160] As can be seen from the above introduction, in order to ensure that the uplink signal arrives at the satellite base station with the downlink signal in time, the UE needs to make timing adjustments in advance when sending the uplink signal, such as... Figure 5a As shown, the large round-trip time delay in NTN causes a significant difference between the timing of the uplink signal received by the satellite base station and the timing of the downlink signal. Therefore, the amount of advance adjustment for the uplink signal timing in the NTN system is relatively large.

[0161] To introduce the problem that this application needs to solve: For example, after the UE receives the physical downlink shared channel (PDSCH) data sent by the base station, the UE needs to send a hybrid automatic repeat request (HARQ)-acknowledge (ACK) (HARQ-ACK) message to the base station to indicate that the PDSCH has been correctly received.

[0162] For example, if a UE receives PDSCH data in slot n, the UE needs to send a HARQ-ACK message in slot n+K1. That is, the maximum timing advance adjustment the UE can make is K1 slot lengths. Generally, the maximum value of K1 is 15. When the subcarrier spacing (SCS) is 30kHz, and one slot length is 0.5ms, then the maximum timing advance adjustment the UE can make is 7.5ms. Figure 2 It is known that the round-trip delay between the UE and the base station in NTN is much greater than 7.5ms. Therefore, a time slot length of K1 is insufficient to provide the UE with enough time to perform timing advance adjustments, i.e., it cannot meet the timing advance requirements for beam or cell round-trip delay compensation in NTN. Specifically, for example... Figure 5b As shown, when the timing advance adjustment of the uplink data sent by the UE is greater than the length of K1 slots, the UE is unable to send the HARQ-ACK message on time.

[0163] One solution to this problem is to introduce a timing offset K. offset This allows sufficient time for the UE to perform timing adjustments between receiving PDSCH data and sending the HARQ-ACK message. Specifically, on the satellite base station side, in n+K1+K...offset Receive HARQ-ACK messages in the time slot. For example... Figure 5c As shown, K is introduced. offset Value, UE can be accessed via K offset The value is used to adjust the time slot in which the UE sends the HARQ-ACK message, so that the UE has enough time to make timing adjustments in advance.

[0164] Therefore, the method provided in this application will be introduced from the following aspects. First, a method for updating timing offsets according to this application will be introduced; second, the method for sending the first timing offset, the method for sending the second timing offset, the effective time, and the update method involved in this method will be introduced; next, the switching scenario involved in this application will be introduced; finally, another method for updating timing offsets according to this application will be introduced.

[0165] Figure 6 This is a flowchart illustrating a method for updating a timing offset provided in this application. Optionally, this method can be applied to a four-step random access scenario. Figure 6 As shown, the method specifically includes:

[0166] 603. The UE determines the timing offset K based on the first timing offset K. offset1 Send a third message (Msg3) to the base station; wherein the first timing offset is used to indicate the degree of delay in the UE sending the third message, and the third message includes indication information, which is used to indicate a second timing offset, which is the updated first timing offset.

[0167] Accordingly, the base station receives the third message sent by the UE according to the first timing offset; the first timing offset is used to indicate the degree of delay in the base station receiving the third message.

[0168] The UE sends a third message to the base station based on the first timing offset. This can be understood as follows: For example, if the UE receives a RAR message in time slot n when the base station is transmitting a signal, then in time slot n+K2+Δ+K when transmitting a signal to the base station... offset1 The third message is sent. Similarly, the base station receives the signal sent by the UE in time slot n+K2+Δ+K. offset1 The system receives the third message. Here, K2 is a parameter indicated to the UE by the base station via broadcast or downlink control information (DCI), and Δ is a pre-agreed value. This application does not limit the specific values ​​or sources of K2 and Δ.

[0169] The first timing offset can also be referred to as the initial timing offset. Optionally, the UE can obtain the first timing offset from the broadcast message; or, the UE can determine the first timing offset based on the relevant adjustment parameters broadcast in the broadcast message. It is understood that the method by which the UE obtains the first timing offset based on the relevant adjustment parameters will be discussed below, and will not be detailed here. Similarly, how the UE indicates the second timing offset to the base station will also be discussed below, and will not be detailed here.

[0170] Optionally, before step 603 above, Figure 6 The method shown also includes:

[0171] 601. The UE sends a first message (Msg1) to the base station, which includes a random access preamble.

[0172] Accordingly, the satellite base station receives the first message sent by the UE.

[0173] In this embodiment of the application, in the satellite transparent transmission scenario, the base station is equivalent to Figure 3 The ground station shown; in the satellite regeneration scenario, the base station is equivalent to... Figure 3 The satellite base station shown.

[0174] 602. The base station sends a second message (Msg2) to the UE, which includes a random access response (RAR) message.

[0175] Accordingly, the UE receives the second message sent by the base station.

[0176] Optionally, before step 605, Figure 6 The method shown also includes:

[0177] 604. The base station sends a fourth message to the UE, which includes a random access contention resolution message.

[0178] Accordingly, the UE receives the fourth message.

[0179] Specifically, after the UE receives the second message sent by the base station, the UE can obtain the timing advance (i.e., TA value or TA_New) based on the timing advance command contained in the second message and the common timing advance (or the timing advance previously used by the UE); further, the UE adjusts the timing advance of the transmitted signal according to the timing advance. Even further, based on the timing advance, the UE can also determine the second timing offset. Optionally, the timing advance TA_New and the second timing offset can satisfy the following formula (1):

[0180]

[0181] Where TA_New is the timing advance used by the UE when sending the third message; slot_duration is the duration unit; symbol This indicates rounding up. It can be understood that the unit of duration can be the time slot length, such as the time slot length for uplink data or downlink data. Alternatively, the unit of duration can also be any of 0.5ms, 1ms, symbol length, subframe length, frame length, etc.

[0182] Optionally, considering the impact of processing latency and the altitude of the UE, a fixed value, such as Δt, can be added to or subtracted from TA_New when calculating the second timing offset. △t is a time value, which can be a value pre-agreed upon through a protocol. The dimension of △t can be different from that of TA_New. Or, in K... offset2 Based on this, add or subtract a fixed value, such as △D, that is... △D is an integer value, which can be a value agreed upon in advance through a protocol.

[0183] It is understandable that formula (1) uses rounding up as an example to illustrate the relationship between timing advance and second timing offset. In specific implementation, the second timing offset can also be determined by rounding down.

[0184] As you can understand, the above explanations of rounding up and rounding down also apply to the following text.

[0185] After obtaining the second timing offset according to formula (1), in some embodiments, the UE can determine whether to update the first timing offset using the second timing offset based on an update threshold. For example, if the update threshold is 1, then if the difference between the timing offset obtained according to formula (1) and the first timing offset is less than or equal to 1, the UE can determine not to update the first timing offset. Conversely, if the difference between the timing offset obtained according to formula (1) and the first timing offset is greater than or equal to 1, the UE can determine to update the first timing offset, and the timing offset obtained according to formula (1) is the second timing offset. It is understood that this application does not limit whether the UE updates the first timing offset when the update threshold is 1. For example, the update threshold can also be 2, etc. When the update threshold is large, the frequency of updating the first timing offset will decrease, thereby reducing signaling overhead and avoiding frequent use of third messages and other messages to carry indication information during the RRC connection phase.

[0186] Furthermore, after the UE determines the first timing offset to be updated, the UE sends an indication message to the base station; the base station receives the indication message sent by the UE.

[0187] Understandably, this update threshold can be pre-set by the base station or the protocol. Alternatively, the UE can obtain it through a broadcast message, which may include one or more of the following: System Information Block (SIB), Master Information Block (MIB), and Other System Information (OSI). Alternatively, the UE can also obtain the update threshold through one or more of the following: Radio Resource Control (RRC) messages, Downlink Control Information (DCI), Group DCI, Media Access Control (MAC), and Timing Advance Command (TAC). Optionally, in addition to obtaining the update threshold through broadcast or unicast messages, the UE can also obtain it through multicast. Optionally, the update threshold may also be carried with data transmission or in a separately allocated PDSCH.

[0188] The above are merely examples. This application does not limit how the UE obtains the update threshold or the specific value of the update threshold.

[0189] After the UE obtains the second timing offset according to formula (1), in some embodiments, after the UE sends an indication message to the base station, the base station can also determine whether to update the first timing offset using the second timing offset based on an update threshold. For details on how the base station updates the offset, please refer to the UE description; it will not be elaborated here.

[0190] Optionally, after the base station determines to update the first timing offset, the base station may also send a second timing offset, the change between the second timing offset and the reference timing offset, or adjustment parameters for indicating the second timing offset to the UE via a Msg4 message. The reference timing offset is either the timing offset currently used by the UE, the timing offset configured by the base station (e.g., the timing offset configured via a broadcast message), or a pre-set fixed timing offset. The timing offset currently used by the UE may be the first timing offset described above. The pre-set timing offset can be understood as the reference timing offset being pre-defined by the base station or the protocol. It is understood that the reference timing offset used in the following description of this application will also be used.

[0191] For example, if the base timing offset is 20 and the second timing offset is 21, then the change can be +1. Or, for example, if the base timing offset is 20 and the second timing offset is 19, then the change can be -1. Alternatively, the change can also be 0. The examples shown above use the second timing offset minus the base timing offset, but in the embodiments of this application, the change can also be obtained by subtracting the second timing offset from the base timing offset.

[0192] It is important to note that the adjustment parameters indicating the second timing offset included in Msg4 may differ from those used in the third message. For example, the first adjustment parameter in the third message might be the timing advance used by the UE to send the third message, while the adjustment parameters in Msg4 might be related to the difference between the second and first timing offsets. Furthermore, after receiving the second timing offset, the adjustment parameters indicating the second timing offset, or the change between the second and reference timing offsets included in Msg4, the UE can update the first timing offset. Once the second timing offset takes effect, the UE can send the fifth message based on it.

[0193] To illustrate more clearly 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 example is provided.

[0194] For example, if the UE obtains a second timing offset of 15 and a first timing offset of 14 according to formula (1), and the update threshold is 2; and the UE determines whether to use the second timing offset to update the first timing offset, since the difference between the first and second timing offsets is less than 2, the UE can determine not to update the first timing offset. Therefore, to save signaling overhead, the UE can choose not to send an indication message to the base station. If the base station determines whether to use the second timing offset to update the first timing offset, the UE can indicate that the second timing offset is 15 through the indication message. Upon receiving this indication message, the base station can determine not to update the first timing offset based on the fact that the difference between the first and second timing offsets is less than 2 and the update threshold is 2. Furthermore, Msg4 may not include the second timing offset.

[0195] For example, if the UE obtains a second timing offset of 17 and a first timing offset of 14 according to formula (1), and the update threshold is 2; and the UE determines whether to use the second timing offset to update the first timing offset, since the difference between the first and second timing offsets is greater than 2, the UE can determine to update the first timing offset. Further, the UE sends an indication message to the base station. If the base station determines whether to use the second timing offset to update the first timing offset, the UE can indicate that the second timing offset is 17 through the indication message. Therefore, after receiving the indication message, the base station can determine to update the first timing offset based on the fact that the difference between the first and second timing offsets is greater than 2 and the update threshold is 2. Further, Msg4 may include the second timing offset.

[0196] It is understood that the above are merely examples and the numbers therein should not be construed as limitations on this application.

[0197] 605. The UE sends a fifth message to the base station according to the second timing offset.

[0198] Accordingly, the base station receives the fifth message.

[0199] The fifth message may include a HARQ-ACK message, which can be a HARQ-ACK message from the fourth message. Alternatively, the fifth message may also include uplink data messages or uplink reference signals (e.g., probe reference signals), etc.

[0200] It is understandable that the description of the UE sending the fifth message to the base station according to the second timing offset can be found in the description of the UE sending the third message to the base station according to the first timing offset, which will not be detailed here. The description of the effective time of the second timing offset can be found below.

[0201] The technical solution provided in this application has two advantages: firstly, by setting a timing offset, the UE has sufficient time to adjust its timing in advance; secondly, by updating the timing offset, such as updating the first timing offset or updating the second timing offset, the UE can use a suitable timing offset. Compared to not updating the timing offset, the embodiments of this application, while ensuring that the UE has sufficient time to adjust its timing in advance, can also reduce end-to-end latency and avoid resource waste.

[0202] For example, in an NTN system, the relative distance between the LEO satellite and the UE is constantly changing, which also means that the round-trip time is constantly changing. If the timing offset K is not updated... offset Therefore, the UE needs to use a larger K. offset The value is used to ensure normal communication. Therefore, if K is not updated...offset The delay length for the UE to send feedback messages (e.g.) Figure 7a The K1+K shown offset There may be situations where the timing lead time is much greater than the actual lead time. For example... Figure 7a As shown, after sending data 1, the base station continues to send data 2 through 10 until it receives the HARQ-ACK (A / N in the diagram represents ACK or NACK) for data 1 in order to fill the entire time domain resources. Therefore, the base station needs to use 10 processes to avoid wasting time domain resources.

[0203] If K offset If it can be updated, then the delay length for the UE to send HARQ-ACK will not be much greater than the timing advance used by the UE. For example... Figure 7b As shown, the UE uses a more suitable K offset At this point, the number of downlink processes on the base station side can be reduced to 7. Furthermore, K is updated. offset After the base station sends data 1, it waits 6 data lengths before receiving HARQ-ACK feedback, which reduces end-to-end latency compared to the previous 9 data lengths. Therefore, the proposed solution can optimize and reduce the number of downlink data transmission processes by the base station and lower end-to-end latency.

[0204] It is understood that the timing offset K shown in this application offset Unless otherwise specified, the timing offset may include the first timing offset K. offset1 Or the second timing offset K offset2 Or the updated second timing offset, etc. That is, the timing offset K. offset It's a general term with no special meaning.

[0205] The following will provide a detailed introduction. Figure 6 Other methods that may be involved in the methods shown.

[0206] It is understood that the methods shown below can be referenced to each other, or the methods can be combined, and all such solutions fall within the protection scope of this application.

[0207] The method by which the UE obtains the first timing offset from the broadcast message is as follows:

[0208] For example, if the base station determines the timing offset based on the maximum round-trip time, such as

[0209] Where max_RTD represents the round-trip time delay of the point farthest from the base station within the beam or cell area covered by the base station, i.e., the maximum round-trip time delay. The number of bits required to transmit this timing offset under different scenarios is as follows:

[0210] Understandably, in the example shown below, the subcarrier spacing is 120kHz. If the duration unit slot_duration is the slot length, then the duration unit is 0.125ms.

[0211] In a GEO transparent scenario with a cell diameter D = 200km, the maximum round-trip time is 541.1ms; an indication K is required. offset The maximum value is 541.1 / 0.125 = 4329 = 13 bits.

[0212] In a GEO regenerative scenario, with a cell diameter D = 200km, the maximum round-trip time is 270.5ms; an indication K is required. offset The maximum value is 270.5 / 0.125 = 2164 = 12 bits.

[0213] In a LEO-1200 transparent transmission scenario with a cell diameter D = 100km, the maximum round-trip latency is 25.8ms; K needs to be indicated. offset The maximum value is 41.7 / 0.125 = 334 = 9 bits.

[0214] In a LEO-1200 regeneration scenario with a cell diameter D = 100km, the maximum round-trip time is 12.9ms; an indication K is required. offset The maximum value is 20.9 / 0.125 = 168 = 8 bits.

[0215] In a LEO-600 transparent transmission scenario with a cell diameter D = 100km, the maximum round-trip latency is 25.8ms; K needs to be indicated. offset The maximum value is 25.8 / 0.125 = 207 = 8 bits.

[0216] In a LEO-600 regeneration scenario with a cell diameter D = 100km, the maximum round-trip time is 12.9ms; an indication K is required. offset The maximum value is 12.9 / 0.125 = 104 = 7 bits.

[0217] It is understood that the maximum round-trip time in the transparent transmission scenario shown above represents the maximum round-trip time between the reference point, the satellite, and the ground station. Similarly, the maximum round-trip time in the regeneration scenario shown above represents the maximum round-trip time between the reference point and the satellite. This reference point can be a reference point within the coverage area of ​​the beam or cell.

[0218] Optionally, the base station can broadcast the value of the first timing offset to the UE. For example, the base station can use the formula... The first timing offset value is calculated. Considering the impact of processing latency and the altitude of the UE, a fixed value, such as Δt, can be added to or subtracted from max_RTD when calculating the first timing offset. △t is a time value, which can be a value pre-agreed upon via a protocol. The dimension of △t can be different from that of max_RTD. Alternatively, in K... offset1 Based on this, add or subtract a fixed value, such as △D, that is... △D is an integer value, which can be a value pre-agreed upon through a protocol. It is understood that this application does not limit the values ​​or sources of △t and △D.

[0219] As can be seen from the examples above, base stations directly broadcast K in different scenarios. offset1 The specific values ​​required require a large number of bits. Therefore, in order to reduce signaling overhead, the UE can obtain the relevant adjustment parameters from the broadcast message, and then the UE can obtain the first timing offset based on the relevant adjustment parameters.

[0220] The method for determining the first timing offset based on the relevant adjustment parameters broadcast in the broadcast message is as follows:

[0221] It is understandable that in order to obtain the first timing offset, the UE needs to acquire one or more parameters, such as S. K , △K offset , △K offset_time α, β, the base station can send to the UE using the following signaling methods:

[0222] The base station sends the above parameters to the UE via a broadcast message. This broadcast message may include one or more of the following: System Information Block (SIB) 1, Master Information Block (MIB), and Other System Information (OSI). Alternatively, during the Radio Resource Control (RRC) connection phase, when the base station needs to inform the UE of the first timing offset of other cells or beams, it may also send the above parameters to the UE via RRC messages, downlink control information (DCI), group DCI, media access control (MAC), and timing advance command (TAC). Optionally, the base station may also send the above parameters with data transmission or in a separately allocated PDSCH. Optionally, in addition to sending the above parameters via broadcast or unicast messages, the base station may also send the above parameters via multicast. It is understood that the above descriptions of the various parameters also apply to other embodiments of this application.

[0223] Method 1

[0224] Generally, the UE receives RAR-related information from the base station through a preset receiving window. However, due to the significant round-trip time (RTD) in satellite communication, the UE delays for a certain period after sending the random access preamble before opening the receiving window to detect the RAR-related information. Theoretically, the delay start-up time of this RAR receiving window is related to the RRT of the closest point to the base station within the beam / cell covered by the base station, i.e., it is related to the minimum RRT; the timing offset is related to the maximum RRT of the beam / cell covered by the base station. The base station can inform the UE of the RAR receiving window delay start-up time; therefore, to save signaling overhead, the first timing offset can be determined based on the RAR receiving window delay start-up time.

[0225] Optionally, the first timing offset and the delay start-up duration of the RAR receiving window can satisfy the following formula (2):

[0226]

[0227] Among them, K offset1 S is the first timing offset. K RAR_delay is the scale factor, and this scale factor is non-negative; RAR_delay is the delay start time of the RAR receiving window; slot_duration is the duration unit.

[0228] Optionally, the first timing offset and the delay start-up duration of the RAR receiving window can satisfy the following formula (3):

[0229]

[0230] Among them, △K offset This is the timing offset difference, which is an integer value.

[0231] For example, the base station can determine the first timing offset K based on the coverage area of ​​the beam / cell. offset1 The value of , for example, according to the formula mentioned above. Received. Then, the base station, based on the value of RAR_delay broadcast to the UE, sets K... offset1 Substituting RAR_delay into formula (3) yields △K. offset The base station can assign this value to △K. offset The value is sent to the UE via broadcast. Correspondingly, the UE receives RAR_delay and △K. offset The value of is substituted into formula (3) to obtain the value of the first timing offset. Here, slot_duration can be pre-agreed upon or specified by the protocol. It is understandable that, as described above, the base station and UE obtain and use △K. offset The same method applies to parameter S. K And the parameters used to derive the first timing offset in the formulas described below.

[0232] Optionally, the first timing offset and the delay start-up duration of the RAR receiving window can satisfy the following formula (4):

[0233]

[0234] Among them, △K offset_time This is the duration difference, which can be positive, negative, or 0. Furthermore, the dimensions of this duration difference can be different from RAR_delay, thereby saving signaling overhead.

[0235] It is understandable that the value of this time difference can be any value, such as a positive number, a negative number, or 0.

[0236] Optionally, the first timing offset and the delay start-up duration of the RAR receiving window can satisfy the following formula (5):

[0237]

[0238] It is understood that for the explanation of each parameter in formula (5), please refer to formulas (2), (3) and (4).

[0239] It is understandable that the relationship between the first timing offset and the delayed start-up time of the RAR receiving window can take different forms based on the above parameters, and this application does not limit it. For example, according to formulas (2) and (3), the relationship between the first timing offset and the delayed start-up time of the RAR receiving window can also satisfy, such as:

[0240] Method 2

[0241] As described above, the UE receives RAR-related information from the base station through a preset reception window. Therefore, the base station needs to inform the UE of the duration of the RAR reception window (RAR_window). After sending the preamble, the UE detects RAR-related information within the duration of the RAR reception window. Theoretically, the duration of this RAR reception window is related to the round-trip time difference within the beams covered by the base station / cell. Therefore, to save signaling overhead, the first timing offset can be determined based on the duration of this RAR reception window.

[0242] Optionally, the first timing offset and the duration of the RAR receiving window can satisfy the following formula (6):

[0243]

[0244] Optionally, the first timing offset and the duration of the RAR receiving window can satisfy the following formula (7):

[0245]

[0246] Optionally, the first timing offset and the duration of the RAR receiving window can satisfy the following formula (8):

[0247]

[0248] Optionally, the first timing offset and the duration of the RAR receiving window can satisfy the following formula (9):

[0249]

[0250] It is understood that the relationship between the first timing offset and the duration of the RAR receiving window can take different forms based on the above parameters, and this application does not limit this. Other derived formulas are exemplarily obtained, where the first timing offset and the duration of the RAR receiving window can satisfy the following conditions: etc.

[0251] It is understandable that the explanation of each parameter in the formulas of Method 2 can be found in the parameters shown in Method 1.

[0252] Method 3

[0253] Combining Method 1 and Method 2, since the base station needs to inform the UE not only of the duration of the RAR receiving window, but also of the delayed start duration of the RAR receiving window, the first timing offset can also be determined based on the duration of the RAR receiving window and the delayed start duration of the RAR receiving window.

[0254] Optionally, the first timing offset, the duration of the RAR receiving window, and the delayed start-up duration of the RAR receiving window can satisfy the following formula (10):

[0255]

[0256] Optionally, the first timing offset, the duration of the RAR receiving window, and the delayed start-up duration of the RAR receiving window can satisfy the following formula (11):

[0257]

[0258] It is understandable that other methods for deriving the first timing offset can be obtained by modifying formulas (10) and (11) based on the parameters shown in Method 1 and Method 2, for example, or etc.

[0259] It is understandable that the explanation of each parameter in the formulas of Method 3 can be found in the parameters shown in Method 1 and Method 2.

[0260] Method 4

[0261] After the UE sends Msg3 during the four-step random access process, a random access contention resolution timer (ra-ContentionResolutionTimer) is started, and Msg4 is detected. 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 {8ms, 16ms, 24ms, 32ms, 40ms, 48ms, 56ms, 64ms}. However, the round-trip time (RTT) in NTN is relatively large; for example, the RRT in a GEO scenario is approximately 250ms. Therefore, a delay start-up value needs to be introduced for the random access contention resolution timer to ensure that Msg4 is received before the timer expires. Theoretically, the delay start-up duration of this random access contention resolution timer is related to the RRT of the beam covered by the base station / the point closest to the base station in the cell, i.e., it is related to the minimum RRT. Generally, the base station can send the RRT start-up duration RCR_offset of the random access contention resolution timer to the UE via SIB1. To save signaling overhead, the first timing offset can be determined based on the delay start duration of the random access contention resolution timer.

[0262] Optionally, the first timing offset and the delay start duration of the random access contention resolution timer can satisfy the following formula (12):

[0263]

[0264] Optionally, the first timing offset and the delay start duration of the random access contention resolution timer can satisfy the following formula (13):

[0265]

[0266] Optionally, the first timing offset and the delay start duration of the random access contention resolution timer can satisfy the following formula (14):

[0267]

[0268] Optionally, the first timing offset and the delay start duration of the random access contention resolution timer can satisfy the following formula (15):

[0269]

[0270] It is understandable that, regarding the derivation relationship between the first timing offset and the delay start duration of the random access contention resolution timer, other derivation formulas can be obtained using the above parameters, for example: etc.

[0271] It is understandable that the explanation of each parameter in the formulas in Method 4 can be found in the parameters shown in the aforementioned methods.

[0272] Method 5

[0273] Similarly, the base station informs the UE of the duration of the random access contention resolution timer, RCR_timer. Theoretically, the duration of this random access contention resolution timer is related to the round-trip delay difference within the beam / cell covered by the base station. Therefore, to save overhead, the first timing offset can be determined based on the duration of this random access contention resolution timer.

[0274] Optionally, the first timing offset and the duration of the random access contention resolution timer can satisfy the following formula (16):

[0275]

[0276] Optionally, the first timing offset and the duration of the random access contention resolution timer can satisfy the following formula (17):

[0277]

[0278] Optionally, the duration of the first timing offset and the random access contention resolution timer can satisfy the following formula (18):

[0279]

[0280] Optionally, the duration of the first timing offset and the random access contention resolution timer can satisfy the following formula (19):

[0281]

[0282] It is understandable that, regarding the derivation relationship between the first timing offset and the duration of the random access contention resolution timer, other derivation formulas can be obtained using the above parameters, for example: etc.

[0283] It is understood that for the explanation of each parameter in the formulas in Method 5, please refer to the parameters shown in the aforementioned methods.

[0284] Method Six

[0285] Combining methods four and five, since the base station needs to inform the UE not only of the duration of the random access contention resolution timer, but also of the delay start duration of the random access contention resolution timer, the first timing offset can also be determined based on the duration of the random access contention resolution timer and the delay start duration of the random access contention resolution timer.

[0286] Optionally, the first timing offset, the duration of the random access contention resolution timer, and the delay start duration of the random access contention resolution timer can satisfy the following formula (20):

[0287]

[0288] Optionally, the first timing offset, the duration of the random access contention resolution timer, and the delay start duration of the random access contention resolution timer can satisfy the following formula (21):

[0289]

[0290] It is understandable that other methods for deriving the first timing offset can be obtained by modifying formulas (20) and (21) based on the parameters shown in Method 1 and Method 2, for example, or etc.

[0291] It is understandable that the explanation of each parameter in the formulas of Method Six can be found in the parameters shown in the aforementioned methods.

[0292] Method 7

[0293] During the initial access phase, to provide a timing advance for UEs without positioning capabilities to send the random access preamble, the base station broadcasts a common timing advance (TA) to the beam or cell. The UE uses this TA to determine the timing advance to use when sending the random access preamble. The TA can be calculated in the following ways: selecting a reference point (the closest point to the base station) within the beam or cell's coverage area and calculating the round-trip time between the reference point and the satellite (in satellite regeneration scenarios); or, the round-trip time between the reference point, the satellite, and the ground station (in satellite pass-through scenarios). The TA is equal to this round-trip time or equal to this round-trip time plus / minus a fixed value. The reference point can be a point on the serving link or a point on the feeder link; this is not limited here. Similarly, the base station may also send the UE a reference point location coordinate, and the UE calculates the TA based on the round-trip time between the satellite's location and the reference point's location. The TA can be positive or negative.

[0294] For UEs with positioning capabilities, the UE can calculate the timing advance that can be used when sending the random access preamble based on the UE's location information and the satellite's location information (which can be obtained from ephemeris information). However, UEs with positioning capabilities can still obtain the common timing advance that the base station broadcasts to the beam or cell.

[0295] Therefore, the first timing offset can be obtained from the common timing advance TA_common.

[0296] Optionally, the first timing offset and the common timing advance TA_common can satisfy the following formula (22):

[0297]

[0298] Optionally, the first timing offset and the common timing advance can satisfy the following formula (23):

[0299]

[0300] Optionally, the first timing offset and the common timing advance can satisfy the following formula (24):

[0301]

[0302] Optionally, the first timing offset and the common timing advance can satisfy the following formula (25):

[0303]

[0304] It is understandable that, regarding the derivation relationship between the first timing offset and the common timing advance, other derivation formulas can be obtained using the above parameters, for example: etc.

[0305] Understandably, for an explanation of the parameters of each formula in Method 7, please refer to the aforementioned methods.

[0306] Method 8

[0307] The first timing offset can also be determined based on the satellite's orbital altitude H. The satellite's orbital altitude is related to the minimum round-trip time of the base station's coverage area. This orbital altitude can be... Figure 8a The round-trip time to the nadir point is calculated. The satellite's orbital altitude can be obtained from ephemeris information.

[0308] Optionally, the first timing offset and the track height H can satisfy the following formula (26):

[0309]

[0310] Where H is the orbital altitude and c is the speed of light.

[0311] Optionally, the first timing offset and the track height H can satisfy the following formula (27):

[0312]

[0313] Optionally, the first timing offset and the track height H can satisfy the following formula (28):

[0314]

[0315] Optionally, the first timing offset and the track height H can satisfy the following formula (29):

[0316]

[0317] It is understandable that, regarding the derivation of the relationship between the first timing offset and the track height, other derivation formulas can be obtained using the above parameters, for example: etc.

[0318] It is understandable that for the transparent transmission mode, there will be two parts of delay: the power supply link and the service link. Therefore, formulas (26) to (29) and the modified formulas can be further optimized by replacing 2*H / c with 4*H / c.

[0319] It is understandable that the explanation of each parameter in the formulas in Method 8 can be found in the aforementioned methods.

[0320] Method Nine

[0321] The base station sends the reference angle of the serving link and / or the reference angle of the feeder link to the UE for the corresponding coverage beam / cell. For example... Figure 8a As shown, the reference angle of the serving link can be determined based on the angle formed by the reference angle reference point, satellite, and nadir point. The reference point of the serving link can be selected as the point farthest from the satellite within the coverage beam / cell range (or the reference point location can be determined according to the specific network deployment). The nadir point is the intersection of the line connecting the satellite and the Earth's center with the Earth's surface. Therefore, the UE can calculate the round-trip time of the serving link based on the reference angle α: 2*H / cos(α) / c.

[0322] Similarly, such as Figure 8a As shown, the base station can calculate the round-trip time of the feeder link by sending the reference angle of the feeder link to the UE. The reference angle of the feeder link can be determined based on the angle formed by the reference angle point of the feeder link, the satellite, and the sub-satellite point. The reference angle point of the feeder link can be selected from the location of the ground station. Therefore, the UE can calculate the round-trip time in the feeder link based on the reference angle β: 2*H / cos(β) / c.

[0323] Finally, the UE can calculate K based on the reference angle α of the serving link and / or the reference angle β of the feeder link transmitted by the base station. offset1 .

[0324] Optionally, the first timing offset and the reference angle α of the service link can satisfy the following formula (30):

[0325]

[0326] Optionally, the first timing offset and the reference angle β of the feed link can satisfy the following formula (31):

[0327]

[0328] Optionally, the first timing offset can satisfy the following formula (32) with respect to the reference angle α of the service link and the reference angle β of the feeder link:

[0329]

[0330] It is understandable that the derivation relationship between the first timing offset and the reference angle can be further derived using other parameters from the above methods, for example: etc.

[0331] It is understood that the explanations of the parameters in the above formulas can be found in the methods described above.

[0332] Figure 6In the method shown, the indication information can be used to indicate a second timing offset, wherein the method by which the UE indicates the second timing offset to the base station includes:

[0333] Method 1

[0334] The indication information includes a second timing offset. For example, as shown in the example above, the second timing offset can occupy the same number of bits as the first timing offset, such as 13 bits, 12 bits, 9 bits, 8 bits, or 7 bits, etc.

[0335] Method 2

[0336] The indication information includes a first set of adjustment parameters, which is used to determine the second timing offset. In other words, the indication information includes a first set of adjustment parameters, and the base station determines the second timing offset based on this first set of adjustment parameters.

[0337] The first set of adjustment parameters may include one or more of the following parameters:

[0338] Based on the second timing offset K offset2 The parameter determined by the RAR receive window delay start time RAR_delay; or

[0339] Based on the second timing offset K offset2 The parameter determined by the duration of the RAR receive window, RAR_window; or

[0340] Based on the second timing offset K offset2 The parameters determined by the RAR receive window delay duration RAR_delay and the duration of the RAR receive window RAR_window; or

[0341] Based on the second timing offset K offset2 The parameter RCR_offset, which determines the timer's delayed start duration, is used to resolve contention during machine access; or...

[0342] Based on the second timing offset K offset2 The parameter determined by the duration of the random access contention resolution timer, RCR_timer; or

[0343] Based on the second timing offset K offset2 The parameters determined by the delay start duration RCR_offset of the random access contention resolution timer and the duration RCR_timer of the random access contention resolution timer; or

[0344] Based on the second timing offset K offset2 The parameters determined by the common timing advance TA_common; or

[0345] Based on the second timing offset K offset2 The parameters are determined by the orbital height H of the network device; or

[0346] Based on the second timing offset K offset2 And the parameters that determine the round-trip delay between the terminal device and the network device; or

[0347] Based on the second timing offset K offset2 The parameter is determined by the reference angle α of the service link; or

[0348] Based on the second timing offset K offset2 The parameters determined by the reference angle β of the feeder link; or

[0349] Based on the second timing offset K offset2 The parameters are determined by the reference angle α of the service link and the reference angle β of the feeder link; or,

[0350] The timing lead time used by the UE when sending the third message (in different scenarios, this can also be understood as the latest timing lead time used by the UE); or

[0351] The timing offset difference can be the difference between a second timing offset and a reference timing offset. The reference timing offset is either the timing offset currently used by the UE or a preset timing offset. The timing offset currently used by the UE can be the first timing offset mentioned above.

[0352] For example, the first set of adjustment parameters includes the timing advance TA_New used by the UE when sending the third message. After receiving TA_New, the base station can determine the second timing offset according to the formula:

[0353] The method by which the UE sends TA_New to the base station, for example, the UE sends the quantized value N of the TA to the base station. TA The base station received N TA This value is then multiplied by a pre-defined quantization factor S to obtain the actual TA value used by the UE (the unit can be seconds or milliseconds). This reduces the signaling length representing the TA and lowers signaling overhead. For example, assuming the quantization factor S is 100 / (15000*2048) ≈ 3.25µs, TA_New = 4ms. Quantization value N TA = 4ms / 3.25us ≈ 1231, requiring 11 bits. If we use Ts = 32.5ns, which is used in LTE, to quantize the TA value, then 4ms / 32.5ns ≈ 123077, requiring 17 bits. It can be seen that 6 bits are saved.

[0354] For example, to save signaling overhead, the UE can send a parameter value based on the round-trip time (RTD) of satellite orbital altitude to the base station, allowing the base station to calculate the actual TA value used by the UE. For instance, the UE sends a time quantity V to the base station. TA (V TA It can be a positive or negative value. ) The base station will use the round-trip delay between the satellite and the ground point as a time quantity V. TA Adding or subtracting these values ​​yields the TA value used by the UE. If the satellite orbital altitude is H (in meters), then the round-trip time to the satellite's nadir is 2*H / c, where c represents the speed of light (3*10⁻⁶). 8 meters per second. Therefore, the base station can be determined using the formula TA_New = 2 * H / c + V. TA The TA value used by the UE is calculated.

[0355] For example, the UE sends a multiple or scale factor M related to the satellite's orbital altitude (e.g., the satellite's nadir round-trip time) to the base station. TA The base station multiplies the round-trip time (RTD) of the sub-satellite point by this multiplier to obtain the TA value used by the UE. That is, the base station can calculate the TA_New value based on the formula TA_New = 2 * H / c * M. TA The TA value used by the UE is calculated. For example, assuming the satellite's orbital altitude is 600km, the round-trip time (RTD) is 600e3*2 / 3e8 = 4ms. When the UE uses an TA value of 4.2ms, it only needs to send V to the base station. TA A time interval of 2ms is sufficient. The base station calculates the actual TA value used by the UE based on 4 + 0.2 = 4.2ms. If this method is not used, the UE needs to send 4.2ms to the base station, which will consume more bits. Alternatively, the UE can send a value M based on a multiple of the sub-satellite point round-trip time delay. TA M TA =4.2 / 4 = 1.05. There's no need to send 4.2 to the base station, saving signaling overhead.

[0356] For example, the UE receives RAR-related information from the base station through a preset receiving window. Due to the significant round-trip time delay in satellite communication, the UE delays for a certain period (RAR_delay) after sending the preamble before opening the receiving window and starting to detect RAR-related information. The RAR receiving window delay (RAR_delay) is communicated to the UE by the base station. Therefore, to save signaling overhead, the UE can send a parameter value based on the RAR receiving window delay (RAR_delay) to the base station, allowing the base station to calculate the actual TA value used by the UE.

[0357] For example, to save signaling overhead, the UE can send a parameter value based on the common timing offset (TA) to the base station, allowing the base station to calculate the actual TA value used by the UE. It is understood that the above methods can also be used in combination. It is understood that the method for the UE to send the timing advance used by the UE to the base station, as described in this application, applies to all instances of the same method mentioned below. For example, when the UE needs to update the second timing offset during subsequent communication, it can also use this method to send the timing advance used by the UE to the base station.

[0358] For example, the indication information sent by the UE to the base station includes △K = K offset2 -K offset1 That is, △K represents the difference in timing offset. Accordingly, after receiving △K, the base station calculates the time offset according to formula K. offset2 =K offset1 +△K yields K offset2 value.

[0359] Optionally, the UE may send a first set of adjustment parameters to the base station using the method described in this application for obtaining the first timing offset from a broadcast message. It should be noted that K in the method for obtaining the first timing offset from a broadcast message needs to be... offset1 Replace with the updated K offset1 (i.e., the second timing offset K) offset2 ), including formulas (2) through (32) and other formulas listed. The UE sends S to the base station K , △K offset , △K offset_time At least one parameter value among parameters such as α, β, etc.; accordingly, the base station calculates the second timing offset using one of the methods in formula (2) to formula (32) of the method for obtaining the first timing offset from the broadcast message by the UE.

[0360] For example, K in formula (11) offset1 Replace with K offset2 Then UE reference The formula determines △K offset The value of △K. Therefore, the indication information includes △K. offset The UE sends the value to the base station. Correspondingly, the base station receives △K. offset Afterwards, according to K is obtained by calculating the formula. offset2 The value of .

[0361] For example, K in formula (27) offset1 Replace with K offset2 Then UE reference The formula determines △K offsetThe value of △K. Therefore, the indication information includes △K. offset The UE sends △K to the base station. offset Value. Correspondingly, the base station receives ΔK. offset Afterwards, according to K is obtained by calculating the formula. offset2 The value of . The use of the formula here is merely an example and applies to other formulas as well.

[0362] Understandable, although the △K offset The symbol is the same as the one in (3) above, but the meaning is different. In formula (3), △K... offset The value can be broadcast by a base station, etc. In the method of this application, the value of △K... offset This is obtained by transforming formulas (11) and (27) as described above, and it is the value sent by the UE to the base station. offset value.

[0363] Optionally, the UE sends S to the base station K , △K offset , △K offset_time The base station uses the change in at least one of the parameters, such as α, β, etc., to calculate the second timing offset.

[0364] For example, the UE sends parameter S to the base station. K The change value is 0.2, while the S sent by the UE to the base station last time... k The value is 1.3 or the S value sent by the base station to the UE last time. k The value is 1.3 or the agreed-upon baseline S. k The value is 1.3, at which point the base station can obtain the updated S. k The value is 1.3 + 0.2 = 1.5. The base station is based on the formula... The second timing offset is calculated. The use of the formula here is only an example and is not limited to a specific formula.

[0365] Optionally, the indication information may also include △K. offset The index number is like 001. That is to say, different △K offset Different index numbers can be used, as in the table lookup method in Method 3 below.

[0366] Optionally, the indication information may also include the UE's latest location information, which may include the latest three-dimensional location coordinates. Therefore, the base station can calculate the round-trip time delay between the satellite and the UE using the satellite's location and the UE's location, and thus obtain the TA value TA_New currently being used by the UE, according to the formula... Obtain the latest timing offset, K. offset2 .

[0367] Method 3

[0368] In the methods mentioned above, K offset or K offset The difference between the time offset and the reference time offset can also be a fixed discrete value, such as K. offset ∈{1,3,5,7} or K offset ∈{1.5,3.5,5.5,7.5}. By setting discrete timing offsets, K can be reduced. offset The signaling overhead. It is understood that the timing offset here may include a first timing offset, a second timing offset, and an updated second timing offset, etc.

[0369] like Figure 8b As shown, the maximum round-trip delay difference in the beam covered by the base station is 2.28 ms. If K is expressed in units of time slots... offset When the subcarrier width is 120kHz, the minimum time slot length is 0.125ms, then K offset =2.28 / 0.125 = 18.24. Then the UE or base station sends this K... offset 5 bits are needed. K offset Quantify, for example, K offset If K ∈{0,3,6,9,12,15,18,21}, then the UE or base station sends this K. offset Three bits are required. For example, the UE or base station can send this K according to the mapping relationship, as shown in Table 1. offset That is, 100.

[0370] Table 1

[0371] <![CDATA[K offset Bit representation]]> <![CDATA[K offset Value 000 0 001 3 010 6 011 9 100 12 101 15 110 18 111 21

[0372] It is understood that the mapping relationship shown above is merely an example and should not be construed as limiting the embodiments of this application. Similarly, K offset The difference between the time offset and the reference time offset can also be represented by discrete values.

[0373] The methods by which the base station indicates the updated first timing offset to the UE include:

[0374] As mentioned above, "After the base station determines to update the first timing offset, the base station can also send the second timing offset, the change between the second timing offset and the reference timing offset, or adjustment parameters for indicating the second timing offset to the UE via the Msg4 message."

[0375] In this process, after determining the first timing offset, the base station sends an adjustment parameter to the UE to indicate the second timing offset. Sending this adjustment parameter can refer to the methods described above for the UE obtaining the first timing offset from the broadcast message and for the UE indicating the second timing offset to the base station. It is important to note that the K parameter in the method for the UE obtaining the first timing offset from the broadcast message needs to be included. offset1 Replace with the updated K offset1 (i.e., the second timing offset K) offset2 ), including formulas (2) through (32) and other formulas listed. The base station sends S to the UE. K , △K offset , △K offset_time The UE can calculate the second timing offset using one of the following methods: formula (2) to formula (32) in the “Method for UE to obtain the first timing offset from broadcast messages”.

[0376] For example, the adjustment parameters sent by the base station to the UE to indicate the second timing offset include S K , △K offset , △K offset_time The change in at least one of the parameters, such as α, β, etc., is received by the UE, which then calculates the second timing offset using this change value. See the specific example in Method Two, where the UE indicates the second timing offset to the base station.

[0377] The methods for determining the effective time of the second timing offset include the following:

[0378] Method 1

[0379] The base station sends an activation message to the UE, which indicates the activation time of the second timing offset, i.e. the time when the UE and the base station begin to use the second timing offset; accordingly, the UE receives the activation message.

[0380] Optionally, after receiving the third message (including indication information), the base station sends the activation information to the UE. For example, the activation information can be an ACK or NACK message. After receiving the ACK message, the UE updates the timing offset at an agreed-upon time. For example, it can be agreed that the timing offset is updated immediately after the UE receives the ACK message. Alternatively, it can be agreed that the timing offset is updated q time slots after the UE receives the ACK message, where q is a non-negative integer.

[0381] Optionally, this activation information can also be used to complete the update of the second timing offset (K). offset2The `updatecomplete` message indicates that the method is effective when sending an ACK. An example of this method can be found in the section on sending ACK messages.

[0382] In an scalable manner, the UE sends an updated timing offset to the base station. After receiving the updated timing offset from the UE, the base station can send an activation message to the UE. The updated timing offset includes: an updated first timing offset that is also the second timing offset; or, an updated second timing offset.

[0383] Optionally, the activation information may also be included in the fourth message.

[0384] Optionally, the base station may also indicate an effective time to the UE before receiving the third message. This effective time may be applied to the effective time for determining the second timing offset; or it may be applied to the updated second timing offset, etc.

[0385] Optionally, the base station can send activation information to the UE via a broadcast message, which may include one or more of the following: System Information Block (SIB), Master Information Block (MIB), and Other System Information (OSI). Alternatively, during the Radio Resource Control (RRC) connection phase, the base station can also send activation information to the UE via one or more of the following: RRC messages, Downlink Control Information (DCI), Group DCI, Media Access Control (MAC), and Timing Advance Command (TAC). Optionally, the base station can also send activation information along with data transmission or in a separately allocated PDSCH. Optionally, in addition to sending the above parameters via broadcast or unicast messages, the base station can also send activation information via multicast.

[0386] It is understood that this application embodiment does not limit when the base station sends the activation information to the UE, nor does it limit the specific form of the activation information.

[0387] Method 2

[0388] The UE sends an activation information to the base station, which indicates the activation time of the second timing offset; correspondingly, the base station receives the activation information.

[0389] Optionally, the UE may send the activation information to the base station after (or before) sending the third message to the base station. Alternatively, the UE may send the activation information to the base station after (or before) receiving the fourth message from the base station.

[0390] Optionally, the activation information may also be included in a third message;

[0391] Optionally, this activation information can also be included in the Physical Uplink Control Channel (PUCCH) information, etc.

[0392] For details on Method 2, please refer to the explanation of Method 1; it will not be elaborated here.

[0393] Method 3

[0394] For the UE, the second timing offset takes effect m times after the UE sends the third message, where m is a pre-set integer; or, the second timing offset takes effect n times after the UE receives the fourth message, where n is a pre-set integer.

[0395] For the base station, the second timing offset can take effect m times after receiving the third message; or, the second timing offset can take effect n times after the base station sends the fourth message.

[0396] It's understandable that this example uses time slots as the unit, but it's not a limitation. For example, it can be agreed that it takes effect after m subframes or the length of a frame. Alternatively, the unit of m can be specified as milliseconds or microseconds, etc.

[0397] by Figure 9 For example, if the second timing offset or its updated form becomes effective starting in the m-th time slot after the UE sends the third message, then the UE will use the second timing offset or its updated form to transmit signals to the base station starting in the m-th time slot after sending the third message. Correspondingly, the second timing offset or its updated form becomes effective starting in the m-th time slot after the base station receives the third message. That is, the base station will use the second timing offset or its updated form to receive signals transmitted by the UE starting in the m-th time slot after receiving the third message.

[0398] It is understood that m and n can be preset by the base station; or, preset by the protocol, etc., and this application embodiment does not limit this. When preset by the base station, the base station can send the value of m or n to the UE through a broadcast message, multicast message, or unicast message. For example, the above m or n value can be informed to the UE or base station through the method of sending effective information described in Method 1 above, that is, the effective information includes the m or n value.

[0399] It is understandable that the effective time is related to channel latency, and can be a value related to one-way or round-trip latency. Therefore, in addition to notifying the UE or base station of the effective time through the effective information transmission methods described in Methods Two and Three, known parameters related to one-way or round-trip latency can also be used to agree on the effective time. For example, by agreeing on a calculation method through a protocol, the UE and base station can obtain the effective time using the same method. The calculation method for the effective time is shown below:

[0400] or

[0401] or

[0402] or

[0403] or

[0404] or

[0405] or

[0406] or

[0407]

[0408] Based on the above calculation method, add a correction value △T (this correction value can be agreed upon through the protocol or sent by the base station to the UE, and △T is an integer), for example:

[0409] or

[0410] or

[0411] or

[0412]

[0413] For example, when the base station and the UE agree to use the formula To calculate the effective time, the UE and base station substitute the RAR_window and RAR_offset values ​​(which can be obtained from the broadcast message) into the formula to calculate the same m value, and then use this m value to obtain the effective time of the updated timing offset. This method avoids adding new signaling indication m values ​​and can adjust the m value according to the round-trip delay between the beam / cell and the base station, providing greater flexibility.

[0414] It is understandable that the above method of specifying m and n values ​​determines the effective time relative to the time of transmitting and receiving signals. Similarly, the effective time can be specified using absolute time. For example, the base station sends an effective information message to the UE, which includes an effective time. This effective time instructs the UE to begin using the updated timing offset value in the first time slot of the 98th frame of the transmitted signal. Correspondingly, the base station begins receiving the signal using the updated timing offset value in the first time slot of the 98th frame of the received signal from the UE. This absolute time effective time can be sent to the UE using the method of sending m and n values ​​described above, which will not be elaborated upon here.

[0415] After the UE receives the latest timing offset, i.e., the second timing offset, it can use the second timing offset to send base station scheduling data information or control channel information, etc., to the base station after the second timing offset takes effect. The following details the types of the fifth message.

[0416] Method 1

[0417] The fifth message includes HARQ-ACK feedback messages for Physical Downlink Shared Channel (PDSCH) data, such as the HARQ-ACK message in the fourth message (Msg4). Figure 6 In step 605, the UE can be: sending a HARQ-ACK message to the base station according to the second timing offset. This HARQ-ACK message is used to confirm that the conflicting access message has been correctly received; correspondingly, the base station receives the HARQ-ACK message. For example, if the UE receives the PDSCH signal ending in time slot x, then in time slot x+K1+K... offset Send the corresponding HARQ-ACK feedback.

[0418] Method 2

[0419] The fifth message includes uplink data. For example... Figure 6In step 605, the UE can be: sending uplink data scheduled by the base station to the base station according to the second timing offset (the base station sends the uplink data scheduled via RAR authorization and DCI indication); correspondingly, the base station receives the uplink data. For example, if the base station schedules the UE to send Physical Uplink Shared Channel (PUSCH) data via DCI instruction, and the DCI signaling is in time slot x, then the UE in time slot x... Send PUSCH data. Where μ PUScH Related to the subcarrier spacing of PUSCH, μ PUSCH When μ = 0, the PUSCH subcarrier spacing is 15 kHz. PDCCH Related to the subcarrier spacing of the Physical Downlink Control Channel (PDCCH), μ PDCCH When = 0, the PDCCH subcarrier spacing is 15KHz.

[0420] Method 3

[0421] The fifth message includes a sounding reference signal (SRS). The base station sends DCI signaling in time slot x to trigger the aperiodic SRS signal. After receiving the triggering signaling, the UE, in time slot x... Send a non-periodic SRS signal. SRS Related to the subcarrier spacing of the SRS signal, μ PDCCH When = 0, the SRS signal subcarrier spacing is 15KHz.

[0422] It is understood that the communication steps using the updated timing offset described above are merely illustrative examples and are not limited to communication steps using the updated timing offset or the original timing offset. For instance, a base station will use the updated timing offset or the original timing offset when determining the reference resource timing information for transmitting channel state information.

[0423] The following describes how to update the timing offset during subsequent communication after the UE has accessed the system.

[0424] During subsequent communication between the UE and the base station (i.e., after the UE accesses the base station), the relative motion between the UE and the satellite will cause changes in the round-trip time delay between the UE and the base station, thus requiring adjustment of the timing advance used by the UE. Therefore, one approach is for the UE to obtain the timing advance based on a timing advance adjustment command (TA adjustment) sent by the base station. Another approach is for the UE to obtain the timing advance based on its own location information and the base station's location information.

[0425] The following two methods can be used to update the timing offset in subsequent communications:

[0426] The difference between the two methods is whether the timing offset being used is updated (including the second timing offset) is determined by the UE side or the base station side.

[0427] Method 1: The UE side decides whether to update the timing offset, including:

[0428] When a UE receives a timing advance adjustment instruction sent by a base station (e.g., timing advance change rate or timing advance adjustment value, etc.), it can use the timing advance adjustment instruction to adjust the timing advance amount used by its transmitted signal, and determine whether to update the second timing offset based on the adjusted timing advance amount; or, the UE can adjust the timing advance amount used based on its own location information and ephemeris information, and determine whether to update the second timing offset based on the timing advance amount.

[0429] Understandably, the second timing offset here is a general term for the timing offset that the UE is using after accessing the system, and can be understood as the timing offset that the UE and the base station are using. This feature also applies to other embodiments of this application.

[0430] The UE can determine whether to update the second timing offset based on the adjusted timing advance (i.e., the latest timing advance adjustment used by the UE): the timing offset obtained by formula (1) and the timing offset currently in use can be used to determine whether to update the timing offset (at this time, the latest timing advance adjustment is substituted into TA_New). For specific operations, please refer to Figure 6 The description of the UE determining whether to update the first timing offset using the second timing offset based on the update threshold is not detailed here. If the UE determines to update the timing offset, it sends the updated second timing offset, or a change based on the updated second timing offset and the reference timing offset, or a second set of adjustment parameters, etc., to the base station. Specific transmission methods and parameters can be found in the section "Method for the UE to Indicate the Second Timing Offset to the Base Station" above. It is important to note that the second timing offset in this section needs to be replaced with the updated second timing offset and other relevant replacements.

[0431] For example, K in formula (11) offset1 Replace with the updated K offset2 Then the UE refers to the updated The formula determines △K offset The value of ΔK. Then the second set of adjustment parameters includes ΔK. offset The UE sends △K to the base station. offset Value. Correspondingly, the base station receives ΔK. offset Then, according to the updated The updated K is obtained by calculating the formula. offset2 value.

[0432] For example, the UE sends S to the base station K , △K offset , △K offset_time The base station calculates the corresponding updated second timing offset using the methods in formulas (2) to (32) above, taking at least one parameter value from parameters such as α, β, etc. Alternatively, the UE sends S to the base station. K , △K offset , △K offset_time The base station uses the change in at least one of the parameters, such as α, β, etc., to calculate the updated timing offset value (i.e., the updated second timing offset). For a specific example, please refer to Method 2 in "Method for UE to Indicate Second Timing Offset to Base Station" above.

[0433] Furthermore, after the UE sends the updated second timing offset or second adjustment parameter to the base station, the base station receives the updated second timing offset or second adjustment parameter sent by the UE. And after the updated second timing offset takes effect, the UE sends the uplink data scheduled by the base station to the base station according to the updated second timing offset.

[0434] It is understandable that the relevant methods for determining the effective time of the updated second timing offset can be found in the description of the method for determining the effective time of the second timing offset, and will not be elaborated here.

[0435] Method 2: The base station decides whether to update the timing offset, including:

[0436] When a UE receives a timing advance adjustment command (e.g., timing advance change rate or timing advance adjustment value) from a base station, the timing advance adjustment command is used to instruct the UE to update the timing advance. The UE can adjust the timing advance used for transmitting signals according to the timing advance adjustment command to obtain the adjusted timing advance.

[0437] The UE sends a second timing offset to the base station based on the adjusted timing advance, or based on the change between the updated second timing offset and the reference timing offset, or a second set of adjustment parameters, etc. (refer to Method 1 above). Correspondingly, the base station receives the relevant information sent by the UE, obtains the second timing offset, and then determines whether to update the timing offset, i.e., whether to update the second timing offset. For specific operations, please refer to... Figure 6 The description of how the base station determines whether to use the second timing offset to update the first timing offset based on the update threshold is not detailed here.

[0438] If the base station determines that the timing offset needs to be updated, then the base station sends the updated second timing offset, or an adjustment parameter based on the change between the updated second timing offset and the reference timing offset, or an indication of the updated second timing offset to the UE. The design related to the base station sending the above-mentioned parameters to the UE can be found in the descriptions of the methods described above for the UE to obtain the first timing offset from the 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; these details will not be elaborated here.

[0439] For example, K in the method for obtaining the first timing offset from the broadcast message by the UE offset1 Replace with the updated K offset2 (i.e., the updated second timing offset), including formulas (2) to (32) and other listed formulas. The base station sends S to the UE. K , △K offset , △K offset_time The value of at least one of the parameters such as α, β, etc.; accordingly, the UE can use one of the methods in formula (2) to formula (32) in "Method for UE to obtain first timing offset from broadcast message" to calculate the updated second timing offset.

[0440] Furthermore, the UE obtains the updated second timing offset based on the change between the updated second timing offset and the reference timing offset, or the adjustment parameters used to indicate the updated second timing offset. After the updated second timing offset takes effect, the UE sends uplink data scheduled by the base station to the base station based on the updated second timing offset.

[0441] It is understandable that the relevant methods for determining the effective time of the updated second timing offset can be found in the description of the method for determining the effective time of the second timing offset, and will not be elaborated here.

[0442] It is understandable that the uplink data in the above two methods is only a general term, and it can be any information sent by the UE.

[0443] The UE also needs to update the second timing offset in the following scenarios: when the UE switches cells; when the UE switches beams; or when the UE switches a partial bandwidth BWP.

[0444] It should be understood that different beams can be distinguished in the protocol based on bandwidth part (BWP), transmission configuration indicator (TCI), or synchronization signal block (SSB). In other words, beams can be indicated by BWP, TCI, or SSB. Therefore, the UE and the base station can indicate beam switching through the switching of BWP, TCI, or SSB, so for the UE and / or the base station, the actual switching may be BWP, TCI, or SSB. Therefore, the beams described in this application can also be replaced by BWP, TCI, or SSB.

[0445] In beam switching scenarios, in this embodiment, the beam before switching can be called the serving beam, and the beam after switching can be called the target beam. Furthermore, the base station transmitting the serving beam can be called the 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 can be called the target base station (or, the target base station is the base station to which the target beam belongs). Figure 3 For example, the current terminal device is within the coverage area of ​​beam #2, which is the serving beam of the terminal device. The beam #3 (or beam #1) after the UE handover is the target beam. It can be understood that the serving beam can be replaced by the serving BWP, serving TCI, or serving SSB; correspondingly, the target beam can be replaced by the target BWP, target TCI, or target SSB. For ease of description, the following will use beams as an example to introduce the embodiments of this application.

[0446] In handover scenarios, the timing offsets used in the serving beam and the target beam may differ. Therefore, the UE needs to update the second timing offset. It can be understood that the updated second timing offset referred to here is the timing offset used by the target beam. The following will use the timing offset used by the target beam as an example to illustrate this application.

[0447] The base station can inform the UE of the timing offset to be used in the target beam in advance before the handover, which can be done in the following two ways:

[0448] 1) Send the difference between the timing offset to be used by the UE in the target beam or cell and the timing offset to be used by the UE in the serving beam or cell.

[0449] 2) The UE calculates the timing offset using the timing advance information provided by the base station regarding its use in the target beam or cell. That is... Where TA_value is the timing advance used by the UE in the target cell or beam, K offsetThis represents the timing offset that the UE will use in the target cell or beam. The base station can also calculate the timing offset that the UE will use based on this formula.

[0450] In certain scenarios, the UE needs to inform the base station of the timing offset it will use in the target beam or cell. For example, when the UE performs an inter-satellite handover, it can calculate the timing advance to be used after the handover using its location information and the target satellite's location information (which can be obtained from ephemeris information). In this case, the UE needs to report the timing offset it will use in the target beam or cell. This includes the following two methods:

[0451] 1) The UE informs the base station of the timing offset value it will use in the target beam or cell.

[0452] 2) The UE sends the timing advance it will use in the target beam or cell to the base station. The base station receives the timing advance sent by the UE and then calculates it according to the formula. The timing offset used by the UE in the target beam or cell is calculated. The UE can also calculate the timing offset it will use based on this formula.

[0453] The UE can obtain the timing offset or the difference between the timing offsets used by the target beam or cell through a broadcast message, which may include any one or more of SIB1, MIB, and OSI. Alternatively, the UE can obtain the timing offset used by the target beam through any one or more of RRC messages, DCI, group DCI, MAC, and TAC. Optionally, in addition to obtaining the timing offset used by the target beam through broadcast or unicast messages, the UE can also obtain the timing offset used by the target beam through multicast. Optionally, the timing offset used by the target beam can also be carried with data transmission or in a separately allocated PDSCH. It is understood that the UE can also obtain the change between the timing offset used by the target beam and the reference timing offset through the above methods.

[0454] Furthermore, when a UE performs beam switching, the timing offset used by the UE in the target beam can also be transmitted in the initial BWP signaling, BWP-DownlinkCommon signaling, BWP-UplinkCommon signaling, BWP-DownlinkDedicated signaling, BWP-UplinkDedicated signaling, or MeasObjectNR signaling. Some specific examples are given below:

[0455] For example: When the UE performs a beam switching, after switching to the initial BWP, K is sent in the RRC signaling corresponding to the BWP.offset Other non-initial BWPs issue K in BWP-DownlinkCommon or BWP-UplinkCommon. offset Here K offset It could also be information related to obtaining the timing offset, such as the timing offset value, S... K , △K offset , △K offset_time , α, β, etc., parameter values ​​or parameter differences.

[0456] For example, when a UE performs a beam switching, the base station can send the K signal used in the target beam to the UE via BWP-DownlinkDedicated and BWP-UplinkDedicated signaling. offset ; or the K used in transmitting the target beam offset K used in the service beam offset The difference is sent to the UE. For example:

[0457] For example, the signaling format sent by the base station is as follows:

[0458]

[0459]

[0460] Wherein, the parameter Koffset can represent the K used by the UE in the target beam. offset ; or it may indicate the K used in the target beam. offset K used in the service beam offset Difference. 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 in the signaling, where the value of Koffset is an integer between 0 and 16 determined by the base station.

[0461] Before initiating a BWP, beam, or cell handover, a measurement procedure needs to be triggered. Therefore, the base station can also send the K used by the UE in the target beam to the UE through measurement configuration and the corresponding RRC signaling during handover. offset ; or the K used in transmitting the target beam offset K used in the service beam offset Difference.

[0462] For example, the signaling format sent by the base station is as follows:

[0463]

[0464] According to the inter-cell handover signaling procedure, the K used in the target beam is sent to the UE within the serving cell beam via an RRC reconfiguration message. offset ; Send the K used in the target beam to the UE offset K used in the service beam offset Difference.

[0465] It is understood that the various classification methods shown above can be combined with each other. For example, this application provides a method for updating timing offsets, such as... Figure 10a and Figure 10b As shown.

[0466] like Figure 10a As shown, the method for updating the timing offset includes:

[0467] 1001. Base station broadcast common timing advance (common TA) and first timing offset (K) offset1 ).

[0468] 1002. The UE sends a random access preamble to the base station; correspondingly, the base station receives the random access preamble.

[0469] Optionally, a UE without positioning capabilities can use a common timing advance to send a random access preamble. A UE with positioning capabilities can use a timing advance obtained from the UE's location information and satellite information to send a random access preamble; alternatively, a UE with positioning capabilities can also use a common timing advance to send a random access preamble.

[0470] 1003. The base station sends a random access response to the UE, which includes a timing advance command; correspondingly, the UE receives the random access response.

[0471] 1004. The UE determines the second timing offset based on the timing advance used (i.e. the latest timing advance), as shown in formula (1).

[0472] Optionally, the UE can obtain the second timing offset according to formula (1) and use the update threshold mentioned above to determine how to update the first timing offset using the second timing offset.

[0473] 1005. The UE sends a Msg3 message to the base station according to the first timing offset broadcast; correspondingly, the base station receives the Msg3 message according to the first timing offset; wherein, the Msg3 message includes a second timing offset.

[0474] 1006. The base station sends a contention resolution message or a conflict resolution message to the UE; correspondingly, the UE receives the contention resolution message or the conflict resolution message.

[0475] 1007. The base station sends a timing advance adjustment instruction to the UE; correspondingly, the UE receives the timing advance adjustment instruction.

[0476] 1008. The UE determines the latest timing advance based on the timing advance adjustment command; or, based on the UE's location information and the satellite's location information. Further, after determining the latest timing advance, the UE can calculate the updated second timing offset based on this latest timing advance. The UE then sends this updated second timing offset to the base station.

[0477] 1009. The UE sends uplink data scheduled by the base station to the base station according to the second timing offset; correspondingly, the base station receives the uplink data according to the second timing offset.

[0478] Optionally, after the updated second timing offset takes effect, the UE can also send uplink data scheduled by the base station to the base station according to the updated second timing offset.

[0479] The method illustrated in this application is given by way of example, assuming an uplink subcarrier spacing of 15 kHz. During random access, the maximum round-trip time calculated by the base station based on the beam coverage area is 20.87 ms. K is calculated based on this value. offset1 =21. The base station side will use K offset1 =21 is sent to the UE via broadcast or Msg2, and the UE uses K offset1 =21 Send Msg3. Simultaneously, the UE calculates K based on the latest TA value to be used when sending Msg3. offset1 Whether an update is needed depends on the following: Assume the TA value used by the UE when sending Msg3 is 19.9ms, i.e., TA_New = 19.9ms. The calculation should then proceed accordingly. K offset1 If a change occurs, the UE sends a new K to the base station in Msg3. offset2 =20.

[0480] After the UE successfully accesses the system, the distance between the UE and the satellite will change during subsequent communication between the UE and the base station, and the UE's timing advance will also change accordingly. When the UE calculates the latest timing advance based on the TA adjustment command or TA rate command issued by the base station or based on its own location information and ephemeris information, the timing advance for the UE to transmit uplink data has changed. Assuming the UE is using a TA value of 18.9ms at this time, according to... Discovery and currently in use of K offset2 If they are different, then the UE will use K. offset2 Report to the base station.

[0481] To avoid redundancy, only the following is shown. Figure 10b Zhongyu Figure 10a The methods shown differ in some ways.

[0482] Steps 1101 to 1103 can be referred to as steps 1001 to 1003.

[0483] 1104. The UE sends Msg3 to the base station according to the first timing offset broadcast; correspondingly, the base station receives Msg3 according to the first timing offset; wherein, Msg3 includes the timing advance used by the UE.

[0484] 1105. The base station determines the second timing offset based on the timing advance used by the UE.

[0485] Optionally, after obtaining the second timing offset based on the timing advance used by the UE, the base station may also use the update threshold mentioned above to determine how to update the first timing offset using the second timing offset.

[0486] 1106. The base station sends a contention resolution message or a conflict resolution message to the UE; correspondingly, the UE receives the contention resolution message or conflict resolution message; wherein the contention resolution message or conflict resolution message includes a second timing offset.

[0487] 1107. The base station sends a timing advance adjustment instruction to the UE; correspondingly, the UE receives the timing advance adjustment instruction.

[0488] Furthermore, the UE determines the latest timing advance based on the timing advance adjustment instruction; or, based on the UE's location information and the base station's location information.

[0489] 1108. The UE sends the latest timing advance to the base station; correspondingly, the base station receives the latest timing advance.

[0490] Furthermore, the base station determines the updated second timing offset based on the latest timing advance; and the base station sends the updated second timing offset to the UE.

[0491] 1109. The UE sends uplink data to the base station according to the second timing offset; correspondingly, the base station receives the uplink data according to the second timing offset.

[0492] Optionally, after the updated second timing offset takes effect, the UE can also send uplink data to the base station according to the updated second timing offset.

[0493] Understandable Figure 10a and Figure 10bThese are just two examples. The various classification methods shown in this application can also be combined according to their inherent logic, and all such combinations fall within the protection scope of this application.

[0494] The method described above can be applied to scenarios where the area covered by the base station (beam, cell, or BWP) can include UEs with positioning capabilities, UEs without positioning capabilities, or UEs that do not use positioning capabilities. Alternatively, the method described above can also be applied to scenarios where UEs in the area covered by the base station do not have positioning capabilities or do not use positioning capabilities. For example, since the UE does not have positioning capabilities or does not use positioning capabilities, the UE needs to determine the first timing offset based on the common timing advance amount broadcast by the base station. And formula (1) above can be replaced by formula (33):

[0495]

[0496] Wherein, TA_common is the common timing advance amount, and TA_command is the timing advance adjustment amount included in the random access response.

[0497] Furthermore, the method described above can also be applied to scenarios where the UE strictly adjusts the timing advance amount according to the timing advance command sent by the base station, and where the UE strictly adjusts the timing advance amount according to the timing advance adjustment instruction sent by the base station. Thus, 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 strictly adjusts the timing advance amount according to the method indicated by the base station, after the UE receives Msg2 sent by the base station, the Msg3 sent by the UE may not include the indication information. Also, after the base station sends the timing advance adjustment instruction to the UE, the UE does not send the updated second timing offset; or the second adjustment parameter set, etc., to the base station. That is to say, in this scenario, the UE will strictly adjust the timing advance amount according to the timing advance command (included in Msg2) and the timing advance adjustment instruction sent by the base station. Therefore, both the base station and the UE are aware of the changes in the timing offset. The base station and the UE can agree on a formula for updating the timing offset, and the base station and the UE can update the timing offset according to this formula and the update threshold.

[0498] Therefore, in cases where the UE has no positioning function or does not use positioning function, this method proposes a way to update the timing offset without signaling interaction, which can save signaling overhead. Specifically, it includes:

[0499] The UE adjusts the timing advance amount used according to the timing advance adjustment instruction from the base station. When the timing advance adjustment amount used by the UE changes, the UE can refer to the difference between the timing offset obtained by formula (1) and the timing offset currently in use to determine whether to update the timing offset (at this time, the latest timing advance adjustment amount is substituted into TA_New). For specific operations, please refer to Figure 6 The description of how the UE determines whether to update the first timing offset using the second timing offset based on the update threshold is not detailed here. If the UE determines to update the timing offset, then the new timing offset is adopted based on the effective time. For the design related to the effective time of this updated timing offset, please refer to the description of the method for determining the effective time of the second timing offset; it will not be detailed here.

[0500] While the base station sends a timing advance adjustment command to the UE, it can also calculate the timing advance amount currently being used by the UE. Therefore, the difference between the timing offset obtained from formula (1) and the timing offset currently being used can be used to determine whether to update the timing offset. For specific operations, please refer to [reference needed]. Figure 6 The description of how the base station determines whether to update the first timing offset using the second timing offset based on the update threshold is not detailed here. If the base station determines to update the timing offset, then the new timing offset is adopted based on the effective time. For the design details regarding the effective time of this updated timing offset, please refer to the explanation of the method for determining the effective time of the second timing offset; it will not be detailed here.

[0501] This method saves signaling by having the UE and the base station calculate and update the timing offset using the same formula. Understandably, this method is illustrated using formula (1) and does not limit the specific form of the formula.

[0502] In other words, the UE and the base station can each determine the updated timing offset using the same formula or method, so that the updated timing offset can take effect directly at the agreed time, a pre-set time, or the time specified in the protocol. This method avoids signaling interaction between the UE and the base station, saving signaling overhead.

[0503] The following describes another method for updating the timing offset provided in this application.

[0504] To reduce access latency and signaling overhead, a two-step random access procedure has been proposed, such as... Figure 11As shown, in the first step, the terminal device simultaneously sends a random access preamble and data to the base station. In the second step, the base station sends a random access response to the terminal device. During this two-step random access process, the terminal device sends the random access preamble and data in the first step, thus reducing uplink data transmission latency. Furthermore, the base station does not need to send scheduling information corresponding to Msg3 to the terminal device, thereby reducing signaling overhead. Typically, MsgA can be used to represent the first interaction message in the two-step random access process. MsgA is sent by the terminal device to the base station. The MsgA message includes a MsgA preamble portion and a MsgA data portion. The preamble is transmitted on the MsgA physical random access channel (PRACH), and the data portion is transmitted on the MsgA PUSCH physical channel.

[0505] Figure 12 This is a schematic flowchart of a method for updating timing offsets provided in an embodiment of this application. Optionally, this method can be applied to two-step random access. Figure 12 As shown, the method includes:

[0506] 1201, Base station broadcast first timing offset K offset1 Alternatively, the base station may broadcast one or more of the following: common timing advance (TA), the orbital altitude of the base station, the duration of the MsgB reception window, and the delay start duration of the MsgB reception window. For this method, refer to the aforementioned method for the UE to obtain the first timing offset from the broadcast message; it will not be detailed here.

[0507] 1202. The UE sends MsgA to the base station to request access to the system using the broadcast common TA or its own calculated TA value; correspondingly, the base station receives the MsgA.

[0508] 1203. The base station sends MsgB to the UE; correspondingly, the UE receives the MsgB.

[0509] MsgB includes timed advance commands, leading IDs, etc.

[0510] 1204. The UE, based on the first timing offset K offset1 A MsgB HARQ-ACK message is sent to the base station; correspondingly, the base station receives the HARQ-ACK message.

[0511] Optionally, the UE can also determine the second timing offset K based on the timing advance used. offset2 For this K offset2 With K offset1The relationship between them can be referred to in the above. Figure 6 The update threshold in the MsgB. 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.

[0512] 1205. The UE sends an indication message to the base station; correspondingly, the base station receives the indication message.

[0513] This indication information is used to indicate the second timing offset. It is understood that, regarding how the second timing offset is indicated, the aforementioned method for the UE to indicate the second timing offset to the base station can be referenced.

[0514] After the UE sends an indication message to the base station, the base station receives the indication message sent by the UE and obtains a second timing offset. After the second timing offset takes effect, the UE sends uplink data scheduled by the base station to the base station according to the updated second timing offset.

[0515] It is understandable that the relevant methods for determining the effective time of the second timing offset can be found in the description of the method for determining the effective time of the second timing offset, and will not be elaborated here.

[0516] Optionally, in step 1201 above, the base station may also only broadcast the common timing advance (TA). In this case, a UE without positioning capabilities can use the common TA to send a preamble to request access. A UE with positioning capabilities obtains a more accurate TA value based on its location information and satellite location information (which can be obtained from ephemeris information), and uses this to adjust the timing advance before sending the preamble. Therefore, a UE with positioning capabilities can carry its used TA value in the PUSCH data when sending MsgA. The method for sending the TA value can refer to the method of reporting the latest TA value used in Msg3 in the 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. The relevant design for determining whether to update can be referred to the aforementioned... Figure 6 The update threshold in the data.

[0517] Optionally, if the base station can distinguish whether the UE is using location functionality, in some embodiments, a UE without location functionality may not carry its TA value in MsgA. Methods for distinguishing whether a UE is using location functionality include, for example, distinguishing by different preamble groups, by identifiers in uplink signals, or by whether the UE carries its TA value in MsgA.

[0518] Optionally, if the base station cannot distinguish whether the UE has positioning capabilities, the UE without positioning capabilities will also carry its TA value in the PUSCH data when sending MsgA. The method for sending the TA value can refer to the method for reporting the latest TA value used in Msg3 during the four-step random access procedure.

[0519] In some embodiments, after receiving MsgA, if MsgA carries the TA value used by the UE, then the base station determines the appropriate value according to the formula. or Determine K offset1 Whether an update is needed can be determined, for example, based on the update threshold mentioned above. Here, TAC_value is the adjustment value included in the timing advance adjustment command that the base station needs to send to the UE. It can be understood that the TA value used by the UE carried in MsgA can be used to determine the second timing offset K. offset2 Or it can be used to determine whether the timing offset needs to be updated. Or the base station will use K offset2 The value is sent to the UE via MsgB.

[0520] In other embodiments, if MsgA does not carry the TA value used by the UE, it indicates that the UE uses the broadcast common TA value to send the preamble, thereby both the UE and the base station use the formula. or K was calculated offset2 At this time, both the base station side and the UE side know that the UE is using K. offset2 In this case, the MsgB sent by the base station to the UE may not carry K. offset2 However, if satellite movement and changes in the TA used by the UE are taken into account, the base station can also adjust the K... offset2 Inform the UE via MsgB.

[0521] It is understood that the specific description of the indication method for the second timing offset, as well as the effective time, can be found in the aforementioned method.

[0522] Optional, Figure 12 The method shown may also include:

[0523] The base station sends a timing advance adjustment command to the UE, and the UE receives the timing advance adjustment command.

[0524] The UE sends data information to the base station according to the timing advance adjustment instruction. The data information includes the updated second timing offset; or, the data information includes a second set of adjustment parameters, which is used to determine the updated second timing offset.

[0525] It is understandable that the method of updating the timing offset in the two-step random access method described above can also be applied to UEs in the base station coverage area that do not have positioning function or do not use positioning function. It can also be applied to UEs strictly adjusting the timing advance amount 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.

[0526] The methods described above all involve the UE making timing adjustments in advance. However, there may also be a scenario where the base station compensates for a portion of the delay, and the UE makes timing adjustments in advance for the remaining delay.

[0527] In this case, the parameters related to timing advance mentioned above can all be reduced by the value of uplink signal delay compensation by the base station when the UE determines the timing offset.

[0528] For example, the formula above It can be replaced with the following formula:

[0529]

[0530] max_RTDD = max_RTD – delay_compensated (35)

[0531] Where max_RTDD represents the maximum round-trip delay difference for the satellite-covered beam or cell; delay_compensated represents the delay compensation value applied by the base station to the uplink signal. It can be seen that the maximum round-trip delay difference is the difference between the maximum round-trip delay between the UE and the base station in the beam or cell and the delay compensation value applied by the base station.

[0532] For example, the above formula (11) can be replaced by the following formula (36):

[0533]

[0534] For example, the above formula (33) can be replaced by the following formula (37):

[0535]

[0536] The embodiments of this application have been described in detail above. The communication device of this application is described below.

[0537] Figure 13 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application, such as... Figure 13 As shown, the communication device includes a processing unit 1301, a transmitting unit 1302, and a receiving unit 1303.

[0538] In one embodiment, the processing unit 1301 is configured to generate a third message; the third message includes indication information, which indicates a second timing offset, the second timing offset being an updated first timing offset, and the first timing offset indicating the degree of delay in the communication device sending the third message.

[0539] The sending unit 1302 is configured to send a third message to the network device according to the first timing offset; the sending unit 1302 is also configured to send a fifth message to the network device according to the second timing offset.

[0540] In one possible implementation, the sending unit 1302 is further configured to send a first message to the network device, the first message including a random access preamble; the receiving unit 1303 is further configured to receive a second message sent by the network device, the second message including a random access response message; and the receiving unit 1303 is further configured to receive a fourth message sent by the network device, the fourth message including a random access contention resolution message.

[0541] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the second timing offset.

[0542] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes a first set of adjustment parameters used to determine the second timing offset.

[0543] In one possible implementation, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the delay start duration of the random access response RAR receive window and the duration of the RAR receive window; or parameters determined based on the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or

[0544] The parameters are determined based on the common timing advance; or based on the orbital altitude of the network device; or based on the round-trip delay between the communication device and the network device.

[0545] In one possible implementation, the fourth message includes the second timing offset; or, the fourth message includes a change based on the second timing offset and a reference timing offset; wherein the reference timing offset is the timing offset currently used by the communication device or a preset timing offset.

[0546] In one possible implementation, the receiving unit 1303 is further configured to receive activation information sent by the network device, the activation information indicating the activation time of the second timing offset; or the sending unit 1302 is further configured to send activation information to the network device, the activation information indicating the activation time of the second timing offset; or the second timing offset becomes effective m time slots after the communication device sends the third message, where m is a preset integer; or the second timing offset becomes effective n time slots after the communication device receives the fourth message, where n is a preset integer.

[0547] In one possible implementation, the receiving unit 1303 is further configured to receive a broadcast message sent by the network device; wherein the broadcast message includes any one or more of the following: the delay start duration of the RAR receive window and the duration of the RAR receive window; or the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or the common timing advance; or the orbital altitude of the network device.

[0548] In one possible implementation, when the broadcast message includes the delay start duration of the RAR receive window and the duration of the RAR receive window, the first timing offset satisfies the following condition:

[0549]

[0550] Among them, K offset1 The value of the first timing offset; the duration of the RAR receiving window, which represents the duration for which the communication device receives the RAR; the delay start duration of the RAR receiving window, which represents the delay duration for which the communication device opens the RAR receiving window after sending the first message; the slot_duration is the unit of duration; the △K offset This is the timing offset difference, ΔK offset It is an integer.

[0551] In one possible implementation, when the broadcast message includes the delay start duration and duration of the random access contention resolution timer, the first timing offset satisfies the following condition:

[0552]

[0553] Wherein, RCR_timer is the duration of the random access contention resolution timer, which represents the maximum allowed time interval between the start of the random access contention resolution timer after the communication device sends the third message and the receipt of the fourth message; RCR_offset is the delay start duration of the random access contention resolution timer, which represents the delay duration for the communication device to start the random access contention resolution timer after sending the third message; slot_duration is the unit of duration; △K offset This is the timing offset difference, ΔK offset It is an integer.

[0554] In one possible implementation, the fifth message includes any one of data information, feedback message, or sounding reference signal (SRS).

[0555] In one possible implementation, the receiving unit 1303 is further configured to receive a timing advance adjustment instruction sent by the network device, the timing advance adjustment instruction being used to indicate the updating of 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 according to the second timing offset, the second adjustment parameter set being used to determine the updated second timing offset.

[0556] In one possible implementation, the transmitting unit 1302 is further configured to receive an updated second timing offset or a change between the updated second timing offset and the reference timing offset sent by the network device when one or more of the following conditions are met; wherein the one or more conditions include: the communication device switching cells; or the communication device switching beams; or the communication device switching a portion of the bandwidth (BWP).

[0557] It should be understood that when the above-mentioned 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, the receiving unit 1302 may be a receiver, or the sending unit 1302 and the receiving unit 1303 may be integrated into one device, such as a transceiver.

[0558] 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, the receiving unit 1303 may be an input interface, or the transmitting unit 1302 and the receiving unit 1303 may be integrated into one unit, such as an input / output interface or a communication interface, etc.

[0559] The communication device in this application embodiment has any of the functions of the terminal device in the above method, which will not be described again here.

[0560] Reuse Figure 13 In another embodiment, the receiving unit 1303 is configured to receive a third message sent by the terminal device according to a first timing offset; wherein the first timing offset is used to indicate the degree of delay in the network device receiving the third message; and the third message includes indication information, which is used to indicate a second timing offset, the second timing offset being an updated first timing offset; the receiving unit 1303 is also configured to receive a fifth message sent by the terminal device.

[0561] In one possible implementation, 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.

[0562] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes the second timing offset.

[0563] In one possible implementation, the indication information for indicating the second timing offset includes: the indication information includes a first set of adjustment parameters used to determine the second timing offset.

[0564] In one possible implementation, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the delay start duration of the random access response RAR receive window and the duration of the RAR receive window; or parameters determined based on the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or

[0565] The parameters are determined based on the common timing advance; or based on the orbital altitude of the communication device; or based on the round-trip time delay between the terminal device and the communication device.

[0566] In one possible implementation, the fourth message includes the second timing offset; or, the fourth message includes a change based on the second timing offset and a reference timing offset; wherein the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0567] In one possible implementation, the sending unit 1302 is further configured to send activation information to the terminal device, the activation information indicating the activation time of the second timing offset; or the receiving unit 1303 is further configured to receive activation information sent by the terminal device, the activation information indicating the activation time of the second timing offset; or the second timing offset becomes effective m time slots after the communication device receives the third message, where m is a preset integer; or the second timing offset becomes effective n time slots after the communication device sends the fourth message, where n is a preset integer.

[0568] In one possible implementation, the transmitting unit 1302 is further configured to transmit a broadcast message; wherein the broadcast message includes any one or more of the following: the delay start duration of the RAR receive window and the duration of the RAR receive window; or the delay start duration of the random access contention resolution timer and the duration of the random access contention resolution timer; or the common timing advance; or the orbital altitude of the communication device.

[0569] In one possible implementation, when the broadcast message includes the delay start duration of the RAR receive window and the duration of the RAR receive window, the first timing offset satisfies the following condition:

[0570]

[0571] Among them, K offset1 The value of the first timing offset; the duration of the RAR receiving window, which represents the duration for which the terminal device receives the RAR; the delay start duration of the RAR receiving window, which represents the delay duration for which the terminal device opens the RAR receiving window after sending the first message; the slot_duration is the unit of duration; the △K offset This is the timing offset difference, ΔK offset It is an integer.

[0572] In one possible implementation, when the broadcast message includes the delay start duration and duration of the random access contention resolution timer, the first timing offset satisfies the following condition:

[0573]

[0574] Wherein, RCR_timer is the duration of the random access contention resolution timer, which represents the maximum allowed time interval between the start of the random access contention resolution timer after the terminal device sends the third message and the receipt of the fourth message; RCR_offset is the delay start duration of the random access contention resolution timer, which represents the delay duration for the terminal device to start the random access contention resolution timer after sending the third message; slot_duration is the unit of duration; △K offset This is the timing offset difference, ΔK offset It is an integer.

[0575] In one possible implementation, the fifth message includes any one of data information, feedback message, or sounding reference signal (SRS).

[0576] In one possible implementation, the sending unit 1302 is further configured to send a timing advance adjustment instruction to the terminal device, the timing advance adjustment instruction being used to indicate the update of the second timing offset; the receiving unit 1303 is further configured to receive the updated second timing offset or the second adjustment parameter set sent by the terminal device, the second adjustment parameter set being used to determine the updated second timing offset.

[0577] In one possible implementation, the transmitting unit 1302 is further configured to transmit an updated second timing offset or a change between the updated second timing offset and the reference timing offset to the terminal device when any one or more of the following conditions are met; wherein any one or more of the conditions include: the terminal device switching cells; or the terminal device switching beams; or the terminal device switching a portion of the bandwidth (BWP).

[0578] It should be understood that when the above-mentioned communication device is a network device or a component in a network 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, the receiving unit 1302 may be a receiver, or the sending unit 1302 and the receiving unit 1303 may be integrated into a single device, such as a transceiver.

[0579] 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, the receiving unit 1303 may be an input interface, or the transmitting unit 1302 and the receiving unit 1303 may be integrated into one unit, such as an input / output interface or a communication interface, etc.

[0580] The communication device in this application embodiment has any of the functions of the network device in the above method, which will not be described in detail here.

[0581] Furthermore, when the aforementioned processing unit is implemented using a processor, and the receiving unit and transmitting unit are integrated into one unit and implemented using a transceiver, such as... Figure 14 As shown. The communication device 140 includes at least one processor 1420, used to implement the functions of the terminal device in the method provided in the embodiments of this application; or, used to implement the functions of the network device in the method provided in the embodiments of this application. The communication device 140 may also include a transceiver 1410. The transceiver is used to communicate with other devices / appliances via a transmission medium. The processor 1420 uses the transceiver 1410 to send and receive data and / or signaling, and is used to implement the corresponding methods of the above-described method embodiments.

[0582] Optionally, the communication device 140 may further include at least one memory 1430 for storing program instructions and / or data. The memory 1430 is coupled to the processor 1420. The coupling in this embodiment is an indirect coupling or communication connection between devices, units, or modules, and can be electrical, mechanical, or other forms, for information exchange between devices, units, or modules. The processor 1420 may operate in conjunction 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.

[0583] This application embodiment does not limit the specific connection medium between the transceiver 1410, processor 1420, and memory 1430. This application embodiment... Figure 14 The memory 1430, processor 1420, and transceiver 1410 are connected via a bus 1440. Figure 14 The connections between other components are shown in thick lines only and are not intended to be limiting. This bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, Figure 14 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0584] In the embodiments of this application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0585] Understandable, for Figure 14 For a detailed implementation of the communication device shown, please refer to [reference needed]. Figure 13 The functions of the terminal equipment shown; or, Figure 14 The specific implementation method of the communication device shown can also be found in [reference]. Figure 13 The functions of the network devices shown.

[0586] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, apparatuses, or units, or they may be electrical, mechanical, or other forms of connection.

[0587] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of this application, depending on actual needs.

[0588] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0589] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0590] In addition, according to the method for updating timing offset provided in the embodiments of this application, this application also provides a computer program for performing the operations and / or processes performed by the terminal device in the method provided in this application.

[0591] This application also provides a computer program for performing the operations and / or processes performed by a network device in the methods provided in this application.

[0592] This application also provides a computer-readable storage medium storing computer instructions that, when executed on a computer, cause the computer to perform the operations and / or processes performed by a terminal device in the method provided in this application.

[0593] This application also provides a computer-readable storage medium storing computer instructions that, when executed on a computer, cause the computer to perform operations and / or processes performed by a network device using the methods provided in this application.

[0594] This application also provides a computer program product, which includes computer code or instructions, and the method of the method embodiment of this application is implemented when the computer code or instructions are run on a computer.

[0595] This application also provides a computer program product, which includes computer code or instructions, and the method of the method embodiment of this application is implemented when the computer code or instructions are run on a computer.

[0596] This application also provides a wireless communication system, including the terminal device and network device described in the embodiments of this application.

[0597] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0598] Based on the above appendix Figure 6 The description of the relevant methods shows that Msg2 can carry an adjustment parameter △K, which is determined based on the coverage area of ​​the beam where the UE is located. Similarly, the adjustment parameter △K value of Koffset can also be determined based on the coverage area of ​​the cell where the UE is located. Accordingly, it is obtained through the formula for determining Koffset (Koffset=f{Max_RTD_cell,time_duration}), for example, optionally, Max_RTD_cell represents the maximum round-trip time between the UE and the base station within the cell coverage area.

[0599] If the base station performs latency compensation when receiving signals from the UE, then the formula for determining Koffset can be rewritten based on the above methods and formulas. For example, optionally, Koffset can be determined based on the coverage area of ​​the beam. Similarly, alternatively, Koffset can be determined based on the coverage area of ​​the cell, and the above formula can be modified to...

[0600] Instead of carrying △K in Msg2, it can be transmitted in the RRCSetup signaling, i.e., in Msg4. Preferably, when carrying △K-related information in the RRCSetup signaling (msg4), the Koffset used by the UE when sending Msg3 can work (i.e., ensuring that the initial Koffset obtained by the UE based on the broadcast message is greater than the maximum round-trip time).

[0601] Optionally, in the methods described above, only Msg2 can carry the Koffset, meaning the UE directly uses the Koffset transmitted by Msg2 to send Msg3. In this case, the Koffset can be a beam-level or cell-level Koffset.

[0602] The above appendix Figure 6 The related methods are based on the transmission of Koffset in a four-step random access procedure. For a two-step random access procedure, MsgB can be used to transmit ΔK or Koffset. The design should refer to the above formula, and the UE calculates Koffset by combining the broadcast parameters and ΔK according to the agreed formula.

[0603] It is understood that the above formulas are merely illustrative examples and do not limit the specific formula forms for obtaining Koffset and ΔK. For example, broadcast parameters can also include the duration of the RAR receive window, the duration of the RAR receive window delay start, the duration of the random access contention resolution timer, and the duration of the random access contention resolution timer delay start, etc.

[0604] For example, Koffset and ΔK can be obtained using the following formulas:

[0605]

[0606] Where RAR_window is the duration of the RAR receive window; RAR_delay is the delay time for starting the RAR receive window. Alternatively,

[0607]

[0608] or,

[0609]

[0610] Where RCR_timer is the duration of the timer used to resolve random access contention; RCR_offset is the delay start duration of the timer used to resolve random access contention.

[0611] or,

[0612]

[0613] or,

[0614]

[0615] Where TA_common is the common timing advance for broadcasts.

[0616] Compared to directly sending the Koffset value to the UE, signaling overhead can be saved by combining broadcast parameters and ΔK. Furthermore, as shown in Table 2, a comparison of cell-level Koffset, beam-level Koffset, and UE-level Koffset in terms of signaling overhead and end-to-end latency is presented. It can be seen that compared to cell-level Koffset, beam-level Koffset has a smaller end-to-end latency, and compared to UE-level Koffset, beam-level Koffset has lower signaling overhead.

[0617] Table 2 Comparison of different Koffset update mechanisms

[0618] Community-level Koffset Beam-level Koffset UE level Koffset Signaling overhead Low middle high End-to-end delay big middle Small

[0619] Figure 15 This application provides a schematic diagram of a reference-point-based NTN communication system, which allows for updating timing offsets within the system. Optionally, the method for updating the timing offset is applicable to a four-step random access scenario, and specifically includes:

[0620] 1501. The satellite (gNB) broadcasts multiple Koffset values ​​to the cell's coverage area.

[0621] 1502. After receiving the broadcast message, the UE determines the corresponding Koffset value based on the received SSB index number.

[0622] Optionally, in step 1501, the multiple Koffset value information can be Koffset numbers or IDs, such as Koffset1, Koffset2, Koffset3, etc. In step 1502, for example, when the SSB index number received by the UE is 1, the Koffset1 value is used. When the SSB index number received by the UE is 3, the Koffset3 value is used. This method, by establishing a relationship (e.g., mapping) between Koffset values ​​and SSB index numbers, allows the UE to use beam-level Koffset values, which can reduce end-to-end latency.

[0623] Optionally, the satellite can broadcast information such as Koffset1, ΔKoffset2, ΔKoffset3, ΔKoffset4, ... The UE can obtain the corresponding Koffset value using the following formula:

[0624] Koffset1 = Koffset1

[0625] Koffset2=Koffset1+△Koffset2

[0626] Koffset3=Koffset1+△Koffset3

[0627] Koffset4=Koffset1+△Koffset4

[0628] …(Base value + specific variable)

[0629] or,

[0630] Koffset1 = Koffset1

[0631] Koffset2=Koffset1+△Koffset2

[0632] Koffset3=Koffset1+△Koffset2+△Koffset3

[0633] Koffset4=Koffset1+△Koffset2+△Koffset3+△Koffset4

[0634] …(Base value + accumulated value of this variable)

[0635] As can be seen from Table 3, which shows the relationship between the number of synchronization broadcast blocks and the subcarrier spacing and carrier frequency, a maximum of 64 synchronization broadcast blocks (SSBs) can be broadcast when the carrier frequency is greater than 6 GHz. The SSB index is the index of the 64 synchronization broadcast blocks, indicated by 3 bits of the PBCH and 3 bits implicitly represented by the PBCH scrambling mode.

[0636] Table 3 Relationship between the number of synchronous broadcast blocks and subcarrier spacing and carrier frequency

[0637] Subcarrier spacing carrier frequency Number of synchronous broadcast blocks 15k f<3GHz 4 15k 3GHz<f<6GHz 8 30k f<3GHz 4 30k 3GHz<f<6GHz 8 120k f>6GHz 64 240k f>6GHz 64

[0638] Optionally, in step 1501, the multiple Koffset value information can be multiple Koffset reference point coordinates, such as Koffset reference point coordinate 1, Koffset reference point coordinate 2, Koffset reference point coordinate 3, etc. In step 1502, after receiving the broadcast message, the UE calculates the Koffset value to be used using the corresponding Koffset reference point coordinates based on the received SSB index number.

[0639] For example, in Figure 16 In the NTN system architecture diagram shown, which replaces the Koffset value based on reference point coordinates, when the SSB index number received by the UE is 3, the Koffset reference point coordinates 3 are used to obtain the Koffset value to be used. The UE calculates the round-trip time delay (RTD_reference) between the Koffset reference point 3 and the satellite based on the Koffset reference point coordinates 3 and the satellite position coordinates (which can be obtained from ephemeris information), and then calculates the Koffset value to be used based on this round-trip time delay. Optionally, it can be calculated using the following formula:

[0640]

[0641] Optionally, if the impact of service link and feeder link latency on Koffset calculation is considered, for example when the satellite is operating in transparent mode, each UE needs to use two reference points to calculate the Koffset value to be used:

[0642] In step 1501, the multiple Koffset value information can be multiple Koffset reference point coordinates and one Koffset feeder link reference point coordinate (which can be referenced). Figure 8a (and the design described by its method), for example, Koffset feeder link reference point coordinates, Koffset reference point coordinate 1, Koffset reference point coordinate 2, Koffset reference point coordinate 3, etc.

[0643] In step 1502, after receiving the broadcast message, the UE determines the corresponding Koffset value based on the received SSB index number, including: calculating the Koffset value to be used using the Koffset feeder reference point coordinates and the corresponding Koffset reference point coordinates based on the received SSB index number. For example, when the UE receives an SSB index number of 1, it uses the Koffset feeder reference point coordinates and the corresponding Koffset reference point coordinate 1 to obtain the Koffset value to be used. The UE calculates the round-trip time delay (RTD_reference) between the Koffset reference point and the satellite based on the Koffset reference point coordinate 1 and the satellite position coordinates (which can be obtained from ephemeris information). The UE calculates the round-trip time delay (RTD_reference) between the Koffset feeder reference point and the satellite based on the Koffset feeder reference point coordinates and the satellite position coordinates. Then, the UE calculates the Koffset value to be used based on the RTD_reference and RTD_reference_feeder. Optionally, it can be calculated using the following formula:

[0644]

[0645] Optionally, to allow for flexible configuration of broadcast Koffset values ​​or Koffset reference points on the network side, an indicator bit can be added to indicate whether multiple Koffset values ​​or multiple Koffset reference point coordinates are being transmitted. For example... Figure 17 The diagram A shows a Koffset value / Koffset reference point coordinate indicator bit. This bit indicates whether the subsequent transmission is of at least one Koffset value or at least one Koffset reference point coordinate. For example, a 0 indicates that at least one Koffset value is being transmitted, and a 1 indicates that at least one Koffset reference point coordinate is being transmitted. When the indicator bit is 0, the transmitted Koffset values ​​can be: Koffset1, Koffset2, Koffset3… When the indicator bit is 1, the transmitted Koffset reference point coordinates can be: Koffset reference point coordinate 1, Koffset reference point coordinate 2, Koffset reference point coordinate 3… The specific usage of the Koffset value and reference point can be found in the above embodiment. If the influence of the power supply link delay on determining the Koffset value is considered, the Koffset power supply link reference point coordinates can be transmitted together with the Koffset reference point coordinates, such as… Figure 18 The diagram below shows the Koffset value / Koffset reference point coordinate indicator.

[0646] Flexible configuration of broadcast Koffset values ​​and / or Koffset reference points brings benefits to the system operating in different modes:

[0647] 1. Steerable Mode: When the system operates in steerable mode, the coverage area of ​​the satellite beam remains unchanged for a period of time, and the broadcast Koffset reference point also remains unchanged. The system can be configured to broadcast the Koffset reference point via an indicator bit, thus eliminating the need for the system to update this value, which reduces the complexity of system broadcast updates.

[0648] 2. Non-staring mode: When the system is operating in non-staring mode, the coverage area of ​​the satellite beam will move with the movement of the satellite. At this time, the Koffset value of the beam does not change. Therefore, the system can be configured to broadcast the Koffset value through the indicator bit.

[0649] Optionally, based on a similar idea, the Koffset value or Koffset reference point can be replaced with the corresponding Koffset angle value. The UE uses the Koffset angle value to calculate the round-trip delay, and then uses a method similar to that described above to calculate the Koffset value.

[0650] like Figure 19 The diagram illustrates the Koffset angle (Koffset feed link angle). Assuming the satellite's velocity along its direction of motion is V, the satellite (gNB) broadcasts at least one Koffset angle (corresponding to the beam) and one Koffset feed link angle to the UE. The Koffset angle can replace the previously mentioned Koffset value or Koffset reference point, and the Koffset feed link angle can replace the previously mentioned Koffset value or Koffset feed link reference point.

[0651] After the UE obtains the corresponding Koffset angle α and Koffset feeder link angle β according to the SSB index, it can optionally calculate the Koffset to be used according to the following formula (refer to the above embodiment for other formula symbols):

[0652]

[0653] If the UE only obtains the corresponding Koffset angle α based on the SSB index, then optionally, the Koffset to be used can be calculated according to the following formula:

[0654]

[0655] In gaze mode, Koffset is represented by the angle of Koffset, which avoids frequent updates and reduces the complexity of the system broadcast process compared to the Koffset value method.

[0656] The methods for determining the initial timing offset at the cell level and the beam level, as well as the methods for updating the timing offset, have been introduced above. The following sections will further describe the methods for determining the initial timing offset at the beam level and the cell level.

[0657] The method for determining the initial timing offset at the beam level (such as beam specific or beam-specific) is as follows:

[0658] For example, as described above Figure 15 The introduction states that the base station broadcasts multiple Koffsets (also written as K in this article) to the cell's coverage area. offset The UE then determines the corresponding Koffset value based on the SSB index number, TCI number, or beam number. The base station broadcasts multiple Koffset value information to the cell coverage area, including: broadcasting multiple timing offset Koffset values ​​via SIB1 messages, or broadcasting Koffset values ​​corresponding to multiple beams via broadcast messages, such as SIB1 messages. Here, beam-level timing offset refers to the same timing offset value used by all UEs in the corresponding beam, i.e., all using the same beam-level timing offset. For example, the maximum round-trip delay between the gNB and the UE in the beam can be used to determine the beam-level timing offset. The beam-level timing offset includes the beam-level initial timing offset, where "initial" indicates the parameters used in the initial stage (or the first n times, such as the first or second time) of accessing the beam, or the basic parameters used in the beam.

[0659] In one possible implementation, the base station can broadcast multiple Koffset values ​​via the random access configuration generic RACH-ConfigGeneric signaling in the SIB1 message or signaling with similar functionality. The RACH-ConfigGeneric signaling carries the set of parameters required during the terminal's random access to the system. Alternatively, it can be understood as adding multiple Koffset values ​​to the RACH-ConfigGeneric parameters (or signaling, etc.) in the SIB1 signal. For example, the RACH-ConfigGeneric signaling may include one or more variable fields, which are used to indicate the aforementioned multiple Koffset values.

[0660] For example, the RACH-ConfigGeneric parameter can include the variable field Koffset-list, which can represent multiple Koffset values, i.e., timing offset values ​​corresponding to multiple beams. Alternatively, the Koffset-list variable field can include two variable fields: Koffset1 and Koffset-diff. Koffset1 represents the timing offset value of beam 1, and Koffset-diff represents the difference in timing offset between other beams and beam 1. Furthermore, there can be a maximum of 63 timing offset differences, meaning the Koffset-list variable field can represent the Koffsets of 64 beams. These 63 timing offset differences can be used to determine the timing offsets corresponding to 63 beams, and Koffset1 can be used to determine the timing offset corresponding to one beam.

[0661] In other words, the variable field Koffset-diff in the embodiments of this application can be understood as △Koffset2, △Koffset3 or △Koffset4 in the above embodiments.

[0662] For example, the RACH-ConfigGeneric signaling format in the SIB1 message is as follows:

[0663]

[0664] In this embodiment, the value ranges of the variable domain Koffset1 and the variable domain Koffset-diff can be determined based on the maximum round-trip time between cells or beams in the communication scenario supported by the standard protocol (e.g., related to orbital altitude and minimum communication angle), the maximum round-trip time difference between cells or beams, and the time unit slot_duration for calculating the timing offset.

[0665] For example, in a GEO pass-through scenario, when the minimum communication angle is 10 degrees, the maximum round-trip time is 541.46 ms. The duration unit, slot_duration, is taken as the minimum slot length, which is 0.125e-3 s. Other signaling examples below also use the minimum slot length as the duration unit and will not be repeated. Since 541.46e-3 / 0.125e-3 = 4331.68, the variable field Koffset1 needs 13 bits to indicate 0 to 4332. The 13 bits of the variable field Koffset1 can represent the range 0 to 8191. In the above signaling example, only the range 0 to 4332 is used; the unused range 4333 to 8191 can be reserved or used for other indication purposes.

[0666] The range of values ​​for the variable domain Koffset-diff can be determined by the maximum round-trip time difference between beams, satellite orbital altitude, cell size, or minimum communication angle.

[0667] For example, in a GEO transparent transmission scenario, the cell diameter is 450km, the minimum communication angle is 10 degrees, and the maximum round-trip delay difference within the cell is 2.933e-3s. Since 2.933e-3 / 0.125e-3 = 23.464, 6 bits are needed to indicate the value range of -24 to +24. The 6 bits of a timing offset difference in the variable field Koffset-diff can represent -31 to +31. In the above signaling example, only the range of -24 to +24 is used. The unused ranges of -31 to ±25 and +25 to +31 can be reserved for other indication purposes.

[0668] For example, after the UE obtains the Koffset-list signaling, it can 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, then the Koffset value of beam 2 can also be obtained as Koffset1 + the first Koffset-diff value (i.e., Koffset1 + the first timing offset difference), and the Koffset value of beam 3 is Koffset1 + the second Koffset-diff value (i.e., Koffset1 + the second timing offset difference), and so on. As mentioned above, beam numbers, such as beam 1, beam 2, etc., can be associated with SSB index numbers or TCI numbers; for example, the SSB index number or TCI number is the beam number. This signaling transmission method provides flexibility and saves signaling bit overhead in multi-beam scenarios.

[0669] Optionally, it can be agreed that after the UE receives the Koffset-diff value, it subtracts a fixed value to obtain the timing offset difference corresponding to a certain beam that the UE can use. Compared with the above scheme of directly sending the timing offset difference that can be used directly to the UE, this method allows the UE to calculate the timing offset difference corresponding to a certain beam that can be used, leaving the computation to the UE and reducing the computational complexity on the base station side. For example, the Koffset-diff variable field uses 6 bits to represent 0 to 48. When the UE receives the Koffset-diff value, it subtracts a fixed value (assuming the fixed value is 24), so the timing offset difference represented by the UE is in the range of -24 to +24. Specifically, if a certain value in the Koffset-diff variable field is 8, the UE receives this value and subtracts the fixed value of 24 to obtain -16. The UE uses -16 as the timing offset difference for the beam corresponding to this value.

[0670] The method for determining the initial timing offset at the cell level (cell specific or cell-specific) is as follows:

[0671] The base station broadcasts the initial Koffset value of the cell via a broadcast message (e.g., SIB1) or sends the initial Koffset value to the UE via RRC signaling (e.g., RRC Setup, RRC Reconfiguration, or RRC Resume). In other words, the base station can use the above methods to enable UEs within the cell to obtain the initial Koffset value, so that UEs within the cell can use this initial Koffset value. The cell-level timing offset refers to the timing offset value used by all UEs in the corresponding cell, i.e., they all use this cell-level timing offset. For example, the cell-level timing offset can be determined by the maximum round-trip time between the gNB and the UE in the cell. The cell-level timing offset includes the cell-level initial timing offset, where "initial" indicates the parameters used initially when accessing the cell or the basic parameters used in the cell.

[0672] In one possible implementation, the base station can broadcast the Koffset value corresponding to the cell via RACH-ConfigGeneric signaling in the SIB1 message. For example, the RACH-ConfigGeneric signaling may contain one or more variable fields that can be used to indicate the aforementioned Koffset value. For instance, these one or more variable fields may be the variable fields Koffset_initial, Koffset-LEO, Koffset-complement, Koffset-LEO-600, Koffset-LEO-1200, and Koffset-GEO as described in the following embodiments.

[0673] The specific description of the RACH-ConfigGeneric signaling is as follows:

[0674] Method 1

[0675] A new variable field, Koffset_initial, is added to the RACH-ConfigGeneric parameter to represent the initial timing offset used by the UE within the cell. For example, the value range of this variable field Koffset_initial can be determined based on the maximum round-trip time (e.g., related to orbital altitude and minimum communication angle) supported by the standard protocol. It is understood that the description of the value range of this variable field Koffset_initial can be found in the description of variable field Koffset1 above. This signaling transmission method saves signaling overhead compared to beam-level Koffset signaling transmission.

[0676] For example, the RACH-ConfigGeneric signaling format in the SIB1 message is as follows:

[0677]

[0678] Method 2

[0679] Two new variable fields, Koffset-LEO and Koffset-complement, are added to the RACH-ConfigGeneric parameter. These fields can be used to determine the initial timing offset. For example, the value range of Koffset-LEO and Koffset-complement (including the range and / or the number of bits represented) can be determined based on the satellite's orbital altitude range and minimum communication angle. Therefore, to further save signaling bits, the initial timing offset can be combined and indicated based on the orbital altitude range.

[0680] For example, the RACH-ConfigGeneric signaling format in the SIB1 message is as follows:

[0681]

[0682] The newly added variable field Koffset-complement is optional, meaning it can be sent or not. For an example below, please refer to the following section for instructions on whether to send the Koffset-complement parameter or under what conditions.

[0683] For example, in scenarios where the orbital altitude is no higher than 1200km, with a minimum communication angle of 10 degrees, the maximum round-trip time is 41.745895ms, and the initial timing offset is 41.745895e-3 / 0.125e-3 = 333.9672, corresponding to 9 bits. Therefore, the network side can send only Koffset-LEO signaling (9 bits), i.e., without sending Koffset-complement. In this case, only 9 bits of signaling are needed to represent the timing offset parameter, which can be represented in the range of 0 to +334. The range that 9 bits can indicate is 0 to +511. In the above signaling example, only the range of 0 to +334 is used. The unused range of +335 to +511 can be reserved or used for other indication purposes.

[0684] For example, in scenarios with an orbital altitude greater than 1200km, the network side can send Koffset-LEO and Koffset-complement signaling (4 bits) to the UE. Koffset-complement represents the high-order bits, and Koffset-LEO represents the low-order bits. Koffset-LEO and Koffset-complement together form a 13-bit signaling, representing the range 0 to 4332. The range that 13 bits can represent is 0 to 8191. In the above signaling example, only the range 0 to 4332 is used; the unused range 4333 to 8191 can be reserved or used for other indication purposes. The indication range of the combination of Koffset-LEO and Koffset-complement can be referred to the description of the variable field Koffset1 above.

[0685] Therefore, after the UE obtains the Koffset-LEO or Koffset-LEO and Koffset-complement signaling, it can determine the timing offset to be used based on the signaling. This signaling transmission method provides flexibility and saves some signaling bits in scenarios with low orbital altitudes.

[0686] It is understood that the range of Koffset in the signaling example above is merely exemplary. This application does not limit the range of Koffset values, and the range of Koffset values ​​can be agreed upon according to the actual deployment conditions.

[0687] Method 3

[0688] Three new variable fields, Koffset-LEO-600, Koffset-LEO-1200, and Koffset-GEO, are added to the RACH-ConfigGeneric parameter to represent the timing offsets used by the UE within the cell. The value range (including the range and / or the number of bits represented) of Koffset-LEO-600, Koffset-LEO-1200, or Koffset-GEO can be determined based on the satellite's orbital altitude range and minimum communication angle. Specifically, Koffset-LEO-600 represents timing offset parameters related to orbital altitudes not exceeding 600km, Koffset-LEO-1200 represents timing offset parameters related to orbital altitudes greater than 600km but not exceeding 1200km, and Koffset-GEO represents timing offset parameters related to orbital altitudes not exceeding 36000km. The Koffset-LEO-600, Koffset-LEO-1200, or Koffset-GEO parameters can be set as optional; the following example illustrates how to send signaling.

[0689] For example, in scenarios where the orbital altitude is no higher than 600km, the network side can send only Koffset-LEO-600 signaling, i.e., without sending Koffset-LEO-1200 and Koffset-GEO. When the minimum elevation angle is 10 degrees, the maximum round-trip time in the LEO-600 scenario is 25.755ms, and the maximum timing offset is 25.755e-3 / 0.125e-3 = 206.04, corresponding to 8 bits (as described in the LEO-600 transparent transmission scenario in the above embodiment). In this case, only 8 bits of signaling need to be sent for the UE to determine the timing offset, representing a range of 0…+207. The range that 8 bits can indicate is 0 to +255. In the above signaling example, only the range of 0 to +207 is used. The unused range of 208 to 255 can be reserved or used for other indication purposes.

[0690] For example, in scenarios where the orbital altitude is greater than 600km but not greater than 1200km, the network side can send Koffset-LEO-1200 signaling to the UE, i.e., without sending Koffset-LEO-600 and Koffset-GEO. In this case, 9 bits of signaling (corresponding to the description in the LEO-1200 transparent transmission scenario in the above embodiment) need to be sent so that the UE can use it to determine the timing offset. It can be understood that the description of the value range of Koffset-LEO-1200 signaling can be referred to the description of Koffset-LEO above, and will not be detailed here.

[0691] For example, in scenarios where the orbital altitude is higher than 1200km, the network side only needs to send Koffset-GEO signaling, i.e., it does not send Koffset-LEO-600 and Koffset-LEO-1200. In this case, 13 bits of signaling (corresponding to the description in the GEO transparent transmission scenario in the above embodiment) need to be sent so that the UE can use it to determine the timing offset, which is represented by a range of 0 to +4332. It can be understood that the description of the value range of Koffset-GEO signaling can be referred to the description of Koffset-LEO, Koffset-complement and Koffset-LEO-600 above, and will not be detailed here.

[0692] For example, the RACH-ConfigGeneric signaling format in the SIB1 message is as follows:

[0693]

[0694] It is understood that the above signaling format values ​​are merely examples and should not be construed as limiting the embodiments of this application.

[0695] In this embodiment of the application, the base station can also add a new variable field corresponding to the timing offset in the PUSCH-ConfigCommon physical layer uplink shared channel general configuration signaling in SIB1 or the PUSCH-Config physical layer uplink shared channel configuration signaling in RRC signaling. For a detailed description of adding the new variable field corresponding to the timing offset in the PUSCH-ConfigCommon physical layer uplink shared channel general configuration signaling in SIB1 or the PUSCH-Config physical layer uplink shared channel configuration signaling in RRC signaling, please refer to methods one to three above, and will not be detailed here.

[0696] It is understood that the values ​​of each signaling shown in the embodiments of this application are merely examples and should not be construed as limiting the embodiments of this application.

[0697] The methods and embodiments described above can be combined to create timing offset update methods and processes for different scenarios. For example, the following will illustrate the combined updates of cell-level, beam-level, or UE-level timing offsets in different scenarios.

[0698] In other words, the cell-level Koffset, beam-level Koffset, or UE-level Koffset shown above can be used in combination.

[0699] It is understandable that UE-level (UE specific or UE-specific) timing offset means that different timing offset values ​​can be used between UEs in a cell / beam.

[0700] For example, during initial access, the UE obtains the cell-level Koffset value via a broadcast message. After the UE initiates random access, the base station updates its Koffset value to the beam level based on the UE's beam. As shown in Table 2, updating the Koffset from the cell level to the beam level can reduce end-to-end latency. Furthermore, when the UE has higher latency requirements, such as in scenarios requiring low latency, the base station and UE can update the Koffset to the UE level. As shown in Table 2, updating the Koffset to the UE level results in a smaller end-to-end latency (including scheduling latency) compared to using both cell-level and beam-level Koffsets, making it suitable for scenarios with low latency requirements.

[0701] For example, during initial access, the UE obtains the cell-level Koffset value via a broadcast message. 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 latency requirements.

[0702] 1) When the UE has low requirements for latency performance and is not sensitive to latency, the base station can allow this type of UE to continue using the cell-level Koffset, or update it to the beam-level Koffset.

[0703] 2) When the UE has high latency performance requirements and requires low latency, the base station can update the timing offset value used by the UE to the UE-level Koffset. This scheme requires the gNB to send a signaling instruction to the UE to update the Koffset to the beam level or to the UE level, or the UE to request the gNB to update the Koffset to the beam level or to the UE level.

[0704] For example, if the UE requires low latency, the UE can independently determine and report to the base station the updated cell-level Koffset value to the UE-level Koffset value; or, the UE can independently determine and report to the base station the updated beam-level Koffset value to the UE-level Koffset value.

[0705] For example, when a UE has latency performance requirements, it can send indication information to the base station. This indication information can indicate the UE's latency requirements or the level of timing offset the UE requests to use (e.g., cell level, beam level, or UE level). The base station receives this indication information and determines whether to update the timing offset value used by the UE. If an update is needed, the base station sends information indicating the need to update the Koffset value. For instance, the base station can instruct the UE to update to a beam-level Koffset value or a UE-level Koffset value.

[0706] Optionally, the base station can instruct the UE whether to enable the Koffset update mechanism or which Koffset update mechanism to use. If not enabled, the cell-level Koffset will not be used to update to the beam-level or UE-level Koffset, and the UE will not need to report TA or latency requirements or the 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 indicate whether to enable a certain Koffset update mechanism:

[0707] The signaling indicates whether the UE-specific Koffset update mechanism is enabled. If enabled, it means that the base station and UE can update the Koffset from the cell level or beam level to the UE level Koffset. If disabled, it means that the UE continues to use the currently used Koffset level. The benefit is that different Koffset update mechanisms can be selected according to the UE's service requirements and scheduling latency requirements, avoiding the additional overhead of Koffset update signaling.

[0708] The signaling indicates whether the beam-specific Koffset update mechanism is enabled. If enabled, it means that the base station and UE can update the Koffset from the cell level or UE level to the beam level Koffset. If disabled, it means that the UE continues to use the currently used Koffset level. The benefit is that different Koffset update mechanisms can be selected according to the UE's service requirements and scheduling latency requirements, avoiding the additional overhead of Koffset update signaling.

[0709] The signaling indication specifies whether a beam-specific or UE-specific Koffset update mechanism is used, or whether updating the Koffset to other levels is not supported. This signaling indication method tells the base station and / or UE in this scenario whether they support updating the Koffset level to the beam level, the UE level, or not changing the used Koffset level. This signaling indication avoids ambiguity regarding the Koffset update mechanism between the base station and the UE. Furthermore, it offers benefits such as allowing the selection of different Koffset update mechanisms based on the UE's service requirements and scheduling latency requirements, and avoiding the additional overhead of Koffset update signaling.

[0710] The following will illustrate the combination of the above methods and various embodiments in specific scenarios with examples.

[0711] Scenario 1: Update the cell-level Koffset value to the beam-level Koffset value.

[0712] In this scenario, it is assumed that the UE obtains the cell-level Koffset value during initial access.

[0713] For example, when a UE requests access to the system, the base station, such as the gNB, transmits the 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. Here, Koffset_old represents the Koffset value currently used by the gNB and the UE, or the reference timing offset value, or the initial Koffset. Koffset_new represents the updated Koffset value to be used by the gNB and the UE, i.e., the timing offset value updated based on Koffset_old. The gNB can determine the ΔKoffset value here based on the beam-level Koffset; that is, the gNB determines the updated Koffset value Koffset_new to be used by the UE based on the UE's beam (for example, the gNB determines the Koffset_new value based on the maximum round-trip time between the UE and the gNB within the coverage area of ​​the UE's beam), and then obtains the ΔKoffset value according to ΔKoffset = Koffset_old - Koffset_new. The gNB can transmit △Koffset via signaling such as Msg2, Msg4, or RRCsetup. Setting △Koffset as optional in the signaling (meaning it can be sent or not) is to take into account that if the network side decides not to update Koffset, the gNB can choose not to send △Koffset to the UE, that is, the gNB and the UE do not update the Koffset that is currently in use.

[0714] In one possible implementation, the base station can transmit ΔKoffset using the ServingCellConfig signaling in the RRCsetup signaling. The RRCReconfiguration and RRCResume signaling also contain ServingCellConfig signaling, and the ΔKoffset value can also be sent via RRCReconfiguration and RRCResume signaling. For example, the ServingCellConfig signaling includes one or more variable fields that can be used to indicate ΔKoffset.

[0715] Method 1

[0716] A new variable field, Koffset-difference, is added to the ServingCellConfig parameter to represent the timing offset difference ΔKoffset. The UE can use this timing offset difference Koffset-difference to update Koffset. The range of values ​​for Koffset-difference (such as the range or the corresponding number of bits) can be determined based on the maximum round-trip time difference between beams, satellite orbital altitude, cell size, and minimum communication angle.

[0717] For example, in a GEO transparent transmission / regeneration scenario, the maximum round-trip time difference in a cell is 10.3 ms. 10.3e-3 / 0.125e-3 = 82.4 ms. The variable field Koffset-difference requires 8 bits to indicate -83 to 83. The 8 bits of Koffset-difference can represent -127 to +127. In the above signaling example, only the range -83 to 83 is used. The unused ranges -127 to -84 and +84 to +127 can be reserved for other indication purposes. This transmission timing offset difference scheme saves signaling overhead compared to directly transmitting the complete Koffset value.

[0718] For example, the signaling format described above can be as follows:

[0719]

[0720] Method 2

[0721] Add a new variable field, Koffset-difference-list, to the ServingCellConfig parameter or a similar parameter. This field represents the difference between the Koffset value used by the UE in multiple beams within the cell and the cell-level Koffset. In other words, Koffset-difference-list represents multiple Koffset differences; for example, it can represent the differences between the Koffset values ​​corresponding to up to 64 beams and the cell-level Koffset of their respective cells.

[0722] For example, the signaling format described above can be as follows:

[0723]

[0724] In this embodiment, the range of values ​​for the variable field Koffset-difference-list can be determined based on the maximum round-trip time of a cell or beam in the communication scenario supported by the standard protocol (e.g., related to orbital altitude and minimum communication angle), the maximum round-trip time difference between the cell and the beam, and the unit slot_duration for calculating the timing offset.

[0725] For example, in a GEO transparent transmission scenario, the cell diameter is 450km, the minimum communication angle is 10 degrees, and the maximum round-trip delay difference within the cell is 2.933e-3s. Since 2.933e-3 / 0.125e-3 = 23.464, 6 bits are needed to indicate the value range of -24 to +24. The 6 bits of a timing offset difference in the variable field Koffset-difference-list can represent -31 to +31. In the above signaling example, only the range of -24 to +24 is used. The unused ranges of -31 to ±25 and +25 to +31 can be reserved for other indication purposes.

[0726] For example, after a UE obtains the Koffset-difference-list signaling, it can determine the beam level Koffset value corresponding to its beam based on the Koffset value it is currently using (or the Koffset value it received previously or the cell-level Koffset value it is currently using) and the Koffset difference indicated by the variable field Koffset-difference-list. For example, if the Koffset-difference-list indicates 64 Koffset differences, the UE selects the corresponding Koffset difference from the Koffset-difference-list based on its beam number (e.g., determined by the correspondence between the beam number and the SSB number or TCI number). For example, if the beam number is 5, the UE selects the 5th Koffset difference indicated by the Koffset-difference-list (assuming the beam number starts from 1) or the 4th Koffset difference indicated by the Koffset-difference-list (assuming the beam number starts from 0). The UE can obtain the beam-level Koffset value corresponding to its current beam by adding the selected Koffset-difference-list value (i.e., the UE's current Koffset value plus the timing offset difference selected based on the beam number). Both the UE and gNB calculate, obtain, and update the beam-level Koffset value using this method. This signaling transmission method provides flexibility and saves signaling bit overhead in multi-beam scenarios.

[0727] Method 3

[0728] Two new variable fields, Koffset-difference-GEO and Koffset-difference-LEO, are added to the ServingCellConfig parameters to represent the timing offset difference ΔKoffset used for different orbit ranges. The UE can use this timing offset difference to update Koffset. The gNB selects to send Koffset-difference-GEO or Koffset-difference-LEO based on the communication scenario (orbit altitude range). After obtaining Koffset-difference-GEO or Koffset-difference-LEO, the UE can obtain the ΔKoffset value and then update the Koffset value according to Koffset_new = Koffset_old + ΔKoffset.

[0729] Koffset-difference-GEO represents the timing offset difference used in communication scenarios where the orbital altitude is greater than 1200km and less than 36000km. Its range is determined by the maximum round-trip delay difference between beams and is related to the satellite orbital altitude, cell size, and minimum communication angle. For a detailed explanation, please refer to the description of Koffset-difference above. When the orbital altitude of the communication scenario is greater than 1200km and less than 36000km, the network side only needs to send Koffset-difference-GEO signaling, i.e., it does not send Koffset-difference-LEO signaling. In this case, 8 bits of signaling need to be sent for the terminal to determine the timing offset.

[0730] Koffset-difference-LEO represents the timing offset difference parameter for orbital altitudes not exceeding 1200km. Its representation range is determined based on the maximum round-trip delay difference between beams. For example, in the LEO-1200 scenario, the maximum round-trip delay difference within the cell is 3.18ms, 3.18e-3 / 0.125e-3 = 25.44, and the variable field Koffset-difference-LEO requires 6 bits to indicate the range -26 to 26. The 6 bits of Koffset-difference-LEO can represent -31 to +31. In the above signaling example, only the range -26 to 26 is used; the unused ranges -31 to -27 and +27 to +31 can be reserved for other indication purposes. This transmission timing offset difference scheme provides flexibility and saves signaling bits in scenarios with low orbital altitudes.

[0731] For example, the signaling format described above can be as follows:

[0732] Koffset-difference-GEO INTEGER(-83..83)OPTIONAL,

[0733] Koffset-difference-LEO INTEGER(-26..26)OPTIONAL,

[0734] Optionally, the gNB can also send the timing offset difference value ΔKoffset, i.e., the Koffset difference, to the UE via MAC CE signaling. Upon receiving the Koffset difference, the UE updates its Koffset according to Koffset_new = Koffset_old + ΔKoffset. For example, the ΔKoffset value can be represented by the aforementioned 8-bit Koffset-difference signaling or the 6-bit Koffset-difference-LEO signaling sent to the UE via MAC CE signaling. A detailed description of this MAC CE signaling can be found above and will not be elaborated upon here.

[0735] Scenario 2: Update the Koffset value at the beam level.

[0736] In gaze mode, as the relative position of the satellite and the UE changes, the beam-specific Koffset of the UE's beam will change.

[0737] When the system uses the beam-level initial Koffset, the gNB can update the beam-specific Koffset through several signaling methods. This means that both the gNB and the UE still use the beam-specific Koffset, but the specific Koffset value changes during the update. In one possible implementation, the network device can indicate the updated Koffset (i.e., beam-specific Koffset) through RRC signaling, RRC reconfiguration signaling, or MAC CE signaling. For example, the RRC reconfiguration signaling includes one or more variable fields (such as Koffset-list) to indicate the updated Koffset. For example, the ServingCellConfig in the RRC signaling includes ΔKoffset. For example, the MAC CE signaling includes ΔKoffset. These are described in detail below:

[0738] Method 1: RRC Reconfiguration signaling, for example, using RRC Reconfiguration signaling to update the Koffset. The base station sends this RRC Reconfiguration signaling to the UE. After receiving the RRC Reconfiguration signaling, the UE selects the corresponding Koffset value according to its beam and updates the currently used Koffset value. For example, the RRC Reconfiguration signaling includes the updated values ​​of the aforementioned Koffset-list variable fields. The specific signaling length design can be found in the description of the Koffset-list variable field parameters above.

[0739] Method 2: RRC signaling. For example, adding a Koffset difference parameter, such as △Koffset, to the ServingCellConfig in the RRC signaling. △Koffset can 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 UE's beam and the satellite and gateway (e.g., the gNB determines the Koffset_new value based on the maximum round-trip delay between the UE and the gNB within the coverage area of ​​the UE's beam). Then, the △Koffset value is obtained according to △Koffset = Koffset_old - Koffset_new. Therefore, the base station sends this RRC signaling to the UE. After receiving the RRC signaling, the UE updates its Koffset according to Koffset_new = Koffset_old + △Koffset. The signaling design for the Koffset difference can refer to the description of the Koffset-difference variable field parameter above.

[0740] Method 3: MAC CE signaling. For example, the gNB can send the timing offset difference ΔKoffset value, i.e., the Koffset difference, to the UE via MAC CE signaling. The signaling design for the Koffset difference can be found in the description of the Koffset-difference parameter above.

[0741] In Scenario 1 above, when the gNB and UE use the cell-level initial Koffset scheme, after the UE requests access to the system, the gNB and UE update the Koffset from the cell level to the beam level. As the relative positions of the satellite, UE, and gateway change, the beam-level Koffset of the UE's beam will also change, meaning the beam-level Koffset value will change and needs to be updated. The gNB can update the beam-specific Koffset value using the following two signaling methods.

[0742] Through RRC signaling, for example, by using the ServingCellConfig signaling in RRC signaling to carry △Koffset

[0743] Koffset-difference INTEGER(-83..83)OPTIONAL,

[0744] For an introduction to the Koffset-difference variable field, please refer to the description of adding a new variable field Koffset-difference to the ServingCellConfig parameters mentioned above.

[0745] The gNB sends the △Koffset value, i.e. the difference Koffset, to the UE via MAC CE signaling.

[0746] Scenario 3: Update the Koffset value at the UE level.

[0747] When the UE is able to report TA, it means that the UE has established a connection with the gNB and has obtained a usable Koffset value. Therefore, the gNB only needs to update the Koffset based on this value.

[0748] For example, such as Figure 6 In the illustrated embodiment, the UE can use Msg3 to report the TA value to indicate the second timing offset. That is, the UE can send its TA information or location information to the gNB in ​​Msg3 (or other messages, such as those sent when the timing offset needs to be updated later) during the RACH process. If a TA value is sent, it can be the TA value itself, a quantized TA value, an updated Koffset value, or a Koffset difference. After accessing the system, the UE can also report values ​​related to its TA value in other uplink messages, which the gNB uses to determine the updated Koffset value.

[0749] In the method described above where the UE sends indication information to indicate the second timing offset, the UE sends a TA-related value to the gNB. This can be done by subtracting the common TA (which can be positive, negative, or zero) from the TA value the UE is currently using, or by subtracting the absolute value of the common TA from the TA value the UE is currently using (i.e., obtaining the difference between the absolute values ​​of the used TA and common TA), i.e., sending TA-applied (e.g., TA_applied = TA_use - TA_common) to the gNB, or sending half of the TA_applied value to the gNB (which then multiplies it by 2 to obtain the TA_applied value). Here, TA_use represents the TA value the UE is currently using or will soon use, TA_common represents the common TA value, and TA_applied represents the difference between TA_use and TA_common. After receiving the TA-related value sent by the UE, the gNB obtains the TA value the UE is currently using or will soon use based on TA_use = TA_applied + TA_common.

[0750] For example, if 16Ts / 2 u Send TA values ​​in time units if TA_use – TA_common is not an integer multiple of 16Ts / 2 u UE or gNB can be based on or The TA-related value sent by the UE to the gNB is calculated. Here, Ts represents 1 / (15e3*2048) seconds, and μ is related to the subcarrier spacing, i.e., the subcarrier spacing is 2. μ 15kHz.

[0751] In one possible implementation, the UE can indicate the TA or its related value via a third or fifth message or other uplink messages (e.g., authorized PUSCH resources, uplink physical layer control channel messages, etc.). For example, the aforementioned third or fifth message or other 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, etc. below), which can be used to indicate the aforementioned TA or its related value.

[0752] Method 1

[0753] A new variable field, TA-applied (time advance used), is added to represent the TA-related values ​​reported by the UE. The gNB uses the received TA-applied field to determine the TA value used or about to be used by the UE. The range and number of bits for the TA-applied signaling are determined by the orbital altitude, minimum communication angle, and time dimension in the communication scenario.

[0754] For example, when the satellite's orbital altitude is no higher than GEO orbit and the minimum elevation angle is 10 degrees, at 16Ts / 2 u Since the unit of measurement is time, the range of TA-applied needs to be 0 to 4155513, requiring 22 bits to represent. The range that 22 bits can represent is 0 to 4194303. In the signaling example above, only the range of 0 to 4155513 is used. The unused range of 4155514 to 4194303 can be reserved for other indication purposes. For example, after receiving the TA-applied parameter, the gNB can add it to the common TA (quantized common TA value), multiply it by the time unit to obtain the TA value currently used by the UE, or TA-applied can represent the TA value currently used by the UE; that is, multiplying TA-applied by the time unit gives the duration of the TA used by the UE. It is understandable that the protocol supports different satellite orbital altitudes, minimum communication angles, and time units, so the indication range that TA-applied needs to support may differ. The indication range and number of bits of TA-applied can be defined according to the specific communication scenario.

[0755] For example, the signaling format of the above-mentioned TA-applied is as follows:

[0756] TA-applied INTEGER(0..4155513)OPTIONAL,

[0757] Method 2

[0758] Three new variable fields, TA-applied-LEO-600, TA-applied-LEO-1200, and TA-applied-GEO, are added to represent the timing advance values ​​used by the gNB to determine the timing advance values ​​being 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 possible minimum communication angle, and the time unit. Specifically, TA-applied-LEO-600 represents parameters related to the timing advance values ​​used by the UE in communication scenarios with an orbital altitude not exceeding 600 km; TA-applied-LEO-1200 represents parameters related to the timing advance values ​​used by the UE in communication scenarios with an orbital altitude not exceeding 1200 km; and TA-applied-GEO represents parameters related to the timing advance values ​​used by the UE in communication scenarios with an orbital altitude not exceeding 36000 km. Referring to the design principles of the representation range and number of bits of the above-mentioned parameter TA-applied, the representation range and number of bits of TA-applied-LEO-600, TA-applied-LEO-1200 and TA-applied-GEO can be obtained.

[0759] For example, in the Msg3 RRCSetupRequest signaling, relevant signaling for UE reporting of TA (Task Alignment) can be added, such as TA-applied-LEO-600 / TA-applied-LEO-1200 / TA-applied-GEO. The UE obtains the satellite's orbital altitude based on ephemeris information or satellite orbital information, and then selects one of the corresponding TA-applied-LEO-600 / TA-applied-LEO-1200 / TA-applied-GEO signaling to send the TA value. For scenarios where the orbital altitude is no higher than 600km, the UE can use the TA-applied-LEO-600 signaling instead of sending TA-applied-LEO-1200 and TA-applied-GEO. The advantage of this is that in low-Earth orbit satellite communication systems, the UE can use a smaller signaling length to send TA-related values.

[0760] For example, the signaling formats of TA-applied-LEO-600, TA-applied-LEO-1200, and TA-applied-GEO are as follows:

[0761] TA-applied-LEO-600 INTEGER(0..197800)OPTIONAL,

[0762] TA-applied-LEO-1200 INTEGER(0..320609)OPTIONAL,

[0763] TA-applied-GEO INTEGER(0..4155513)OPTIONAL,

[0764] Method 3

[0765] In the method described above where the UE sends indication information to indicate the second timing offset, the UE can report the Koffset value to be updated or the Koffset difference instead of reporting the TA-related value. For example, using the Koffset difference. A new variable field, Koffset_difference_UE, is added to represent the timing offset difference reported by the UE to the gNB, which is the difference between the Koffset value to be updated and the currently used Koffset. It can be understood that the UE can also report the Koffset difference in other uplink messages.

[0766] The range and number of bits occupied by Koffset_difference_UE are related to the frequency and threshold of Koffset updates reported by the UE. Taking a Koffset difference of no more than 7 as an example, Koffset_difference_UE requires 3 bits. After receiving Koffset_difference_UE, the gNB can obtain the Koffset value to be updated for both the gNB and the UE based on Koffset_new = Koffset_old + Koffset_difference_UE.

[0767] For example, the signaling format of the above Koffset_difference_UE is as follows:

[0768] Koffset_difference_UE INTEGER(0..7)OPTIONAL

[0769] In the method described above where the UE sends indication information to indicate the second timing offset, the UE can report its location information to the gNB. For example, an Earth-Centered, Earth-Fixed (ECEF) coordinate system can be used. Assuming the range represents a maximum distance of 20 km from the Earth's surface and the Earth's radius is 6371 km, then each dimension of the three-dimensional coordinate position needs to represent -6391 to 6391 km. When the resolution of each dimension of the three-dimensional coordinate is 0.125 m, 27 bits are required, so the three dimensions require 27 * 3 = 81 bits. When the resolution of each dimension of the three-dimensional coordinate is 0.25 m, 26 bits are required, so the three dimensions require 26 * 3 = 78 bits. For example, a variable field UE-Position can be added to represent the UE's position coordinates. The variable field UE-Position includes three variable values ​​representing the UE's three-dimensional coordinate related values. The representation range and number of bits occupied by the UE-Position signaling are related to the Earth's radius, the highest possible distance of the UE from the horizontal plane, and the resolution of the position coordinate representation. For example, the location information signaling sent by the UE can be represented as:

[0770] UE-Position SEQUENCE(3OF INTEGER(-67108863..67108863))OPTIONAL,

[0771] or

[0772] UE-Position SEQUENCE(3OF INTEGER(-33554431..33554431))OPTIONAL,

[0773] For example, the aforementioned TA-applied-LEO-600, TA-applied-LEO-1200, TA-applied-GEO, UE-Position, or Koffset_difference_UE signaling can be carried in the RRCSetupRequest message.

[0774] When the gNB receives the UE-Position signaling, it multiplies the received 3D coordinate values ​​by the coordinate resolution. For example, assuming the coordinate resolution is 0.125m, and the gNB receives the UE-Position signaling values ​​as (50976000, 1688000, 1592000), the gNB can obtain the UE's actual ECEF 3D coordinates as (50976000*0.125=6372km, 1688000*0.125=211km, 1592000*0.125=199km).

[0775] Optionally, to reduce signaling overhead, it can be agreed that the location coordinates sent by the UE can be subtracted by a fixed value before sending the coordinate difference. For example, the UE can subtract 6371km from each latitude of its three-dimensional coordinates before sending the coordinate difference. After receiving the coordinate difference, the gNB adds 6371km to each latitude to obtain the UE's coordinate value. The above signaling design can save signaling overhead.

[0776] Method 4

[0777] The gNB and UE can agree that the UE reports TA-related parameters to the gNB via uplink physical layer control channel (PUCCH) messages. For example, the UE can send the TA-related signaling parameters reported in the methods and embodiments described in this application, or indication information sent by the UE (for indicating the second timing offset), via uplink physical layer control channel messages. This method can avoid the UE requesting uplink resources to report TA-related parameters, saving uplink resource request and scheduling time.

[0778] In this embodiment of the application, after the UE accesses the system, the UE can send the TA value to the gNB through the uplink MAC CE message or PUSCH, and the above-mentioned design method for the signaling length related to reporting TA can be referred to.

[0779] The above method and examples illustrate how to update Koffset during cell handover. The following example uses a signaling flow diagram specific to a communication scenario:

[0780] 1) During the handover process, measurements are taken first, and then the source gNB sends RRCReconfiguration signaling to the UE. As can be seen from the signaling above, the cell-level or beam-level Koffset exists in the RRCReconfiguration. Therefore, the UE can obtain the Koffset value of the target cell / beam through RRCReconfiguration. For RACHless handover, the source cell also sends RRCReconfiguration signaling to the UE. The UE will receive the SIB1 of the target cell and can similarly obtain the Koffset of the target cell / beam.

[0781] 2) After the UE completes handover, the Koffset can be updated from the cell level to the beam level. Alternatively, it can be updated to the UE level Koffset, following the same signaling procedure as when the UE is randomly connected to a cell.

[0782] Satellite switching is equivalent to cell handover, as described in the handover signaling procedure above.

[0783] The above method and examples illustrate how to update Koffset during beam switching. The following example uses a signaling flow from a specific communication scenario:

[0784] When the source beam and the target beam belong to the same cell, the beam switch does not switch satellites, so the UE can continue to use the currently used cell level or UE level Koffset.

[0785] If the Koffset used by the UE is beam-level, then it needs to be discussed in two categories:

[0786] 1. When the system uses the beam-level initial Koffset scheme, the gNB can update the beam-specific Koffset through the following two signaling methods.

[0787] 1) The Koffset-list is updated via RRC signaling, such as using RRCReconfiguration signaling. The UE selects the corresponding Koffset value according to the beam it is in, that is, it updates the Koffset value that is currently in use.

[0788] or,

[0789] The UE needs to select the Koffset value to be used for the corresponding target beam based on the Koffset group (e.g., Koffset-list message) sent in the broadcast signal.

[0790] 2) The gNB can send the ΔKoffset value, i.e., the Koffset difference, to the UE via MAC CE signaling. After receiving it, the UE updates the Koffset according to Koffset_new = Koffset_old + ΔKoffset. For example, the gNB can send the above 8-bit or 6-bit signaling to the UE to represent the ΔKoffset value via MAC CE signaling.

[0791] 2. When the system uses the cell-level initial Koffset scheme, and the UE uses the beam-level Koffset after accessing the system, the gNB can update the beam-specific Koffset through the following two signaling methods.

[0792] 1) Through RRC signaling, for example, by using the ServingCellConfig signaling in RRC signaling to carry △Koffset (e.g., using the Koffset-difference signaling mentioned above).

[0793] 2) The gNB sends the △Koffset value, i.e. the Koffset difference, to the UE via MAC CE signaling.

[0794] Gateway switch:

[0795] When a soft gateway switch occurs, the UE can receive signals from both gateways simultaneously, which can be equivalent to a cell handover process.

[0796] When a hard gateway switch occurs, the UE can only receive signals from one gateway at a time, instantly switching from the source gateway to the target gateway. During this time, the feeder link latency changes. The gNB can send the UE the Koffset used at the target gateway or the difference between the current Koffset and the Koffset used, i.e., ΔKoffset.

[0797] Since the Koffset value needs to be updated for the UE of the entire beam or cell, the Koffset can be updated by carrying ΔKoffset in the RRCReconfiguration signaling.

[0798] or,

[0799] The gNB uses MAC CE signaling to send the target gateway's Koffset or ΔKoffset to the UE.

[0800] Sending ΔKoffset might require the same number of bits as the full Koffset. For example, in some special scenarios, the network performs timing compensation on the uplink signal before the handover, but not after. In this case, ΔKoffset needs to include the complete round-trip time, and the number of bits required for ΔKoffset is the same as for the full Koffset. If the protocol does not support this type of special scenario, the number of bits required to represent ΔKoffset will be less than the number of bits required to represent the full Koffset, saving signaling bits.

[0801] In the above method for the UE to send indication information to indicate the second timing offset, the UE sends TA-related values ​​to the gNB. The following example illustrates how the UE reports the TA it is using or its related values.

[0802] The UE reports its currently used TA or TA-related value. The gNB determines the UE's TA value and, based on this, determines the Koffset value that the UE needs to update, as described above: Therefore, the following are several methods for a UE to indicate to the base station the TA it is using.

[0803] Method 1: UE reports TA rate

[0804] To save signaling overhead when the UE reports its TA value, the UE can report its current TA rate of change (TA_R) and current TA value (TA_Va) to the gNB. The UE can calculate the TA rate of change based on information such as its location, satellite location, velocity direction, and velocity magnitude. Both the UE and the gNB can calculate the TA value the UE will use subsequently based on TA_R and TA_Va, and then calculate the Koffset value. For example, Where t represents the moment when Koffset is to be calculated or used, and t0 represents the moment when the UE uses the TA_Va value. If the gNB subsequently sends a TAC command to the UE to adjust the TA value, then the formula for calculating Koffset can be adjusted to... Where TAC_ac represents the cumulative value of the TAC commands sent by the gNB to the UE. For example, if the gNB sends two TAC commands to the UE, the sum of the adjustments from the two TAC commands is TAC_ac. It can be agreed that both the UE and the gNB calculate the Koffset value according to the above formula and update it to the latest Koffset value. Alternatively, the gNB calculates the Koffset value according to the above formula, and if an update is needed, it indicates the updated Koffset value or the difference between the latest Koffset and the original Koffset to the UE.

[0805] Method 2: Report the difference in TA

[0806] To save on signaling overhead when the UE reports a TA (Task Value), each time the UE reports the TA value it is currently using, it can report the difference between the TA value it is currently using and the TA value it reported last time, or the difference between the TA value it is currently using and the TA value it previously indicated to the UE by the gNB. This reduces the indication range and signaling bits required for reporting the TA. For example, if the UE previously reported a TA value of TA1 to the gNB, and the TA value it is currently using is TA2, then the UE will report a TA value of TA2-TA1 to the gNB. When the gNB receives the (TA2-TA1) value reported by the UE, it can add it to the TA value TA1 previously reported by the UE to obtain the TA value TA2 that the UE is currently using.

[0807] Method 3: Reporting TA values

[0808] UE periodically reports TA values: The gNB configures resources for periodically reporting TA values ​​to the UE. Therefore, the UE can report the TA it is using based on the resources configured by the base station (the reporting method can be found in the above embodiments). For example, the gNB configures the TA reporting period to be 8 seconds, and time-domain and frequency-domain resources with an 8-second period, in the RRC signaling. The UE periodically reports TA values ​​on these resources.

[0809] Semi-static TA reporting by the UE: In addition to configuring the resources for periodic TA reporting to the UE, the gNB also needs to send activation or deactivation (disabling) signaling to the UE to indicate whether to start the periodic TA reporting function. For example, the gNB can activate or deactivate the periodic TA reporting function through MAC CE. After receiving the activation or deactivation (disabling) signaling, the UE starts or stops periodically reporting TA values.

[0810] UE Aperiodic Reporting of TA Values: The gNB configures uplink resources for reporting TA values ​​to the UE and sends a trigger command to the UE to report TA values. Upon receiving the command (or signaling), the UE reports the TA value it is currently using to the gNB once. For example, the gNB can trigger the UE to report TA values ​​via a DCI command. After receiving the trigger command, the UE reports the TA value immediately or after a pre-defined period. Specifically, if the UE receives a DCI trigger command in downlink time slot n, the UE can report the TA value it is currently using in uplink time slot n+M. Here, M is a non-zero integer, and M is related to the size of the TA value used by the UE, for example... delta is a non-negative integer variable that is agreed upon by the gNB and the UE to take into account the processing delay, or a non-negative integer variable that the gNB configures for the UE.

[0811] The methods described above for reporting TA and TA-related values ​​can be used in combination, and will not be elaborated further here.

[0812] In this embodiment, Koffset can solve the problem that the timing of receiving uplink data on the network side is later than the timing of sending the corresponding downlink data. For example, as Figure 20 As shown, the gNB receives an uplink HARQ-ACK in uplink time slot n corresponding to a PDSCH carrying a MAC-CE instruction (or MAC-CE signaling). This MAC-CE instruction is a downlink signal configuration instruction, and the UE assumes that the downlink configuration is effective in the downlink time slot. The first time slot afterwards, i.e., the time slot in When the subcarrier spacing is 2 μ At 15kHz, the number of time slots contained in a subframe, where X is a non-negative integer agreed upon in the protocol or configured through parameters, such as X = 3.

[0813] For example, the configuration instructions for downlink signals carried in the PDSCH by the MAC CE can be resource configurations for downlink ZP CSI-RS, or deactivation of already active downlink ZP CSI-RS resource configurations. As another example, instructions carried in the PDSCH can indicate the mapping relationship between TCI status and code points ('Transmission Configuration Indication') in the DCI domain. As yet another example, instructions carried in the PDSCH can activate / deactivate semi-static CSI reporting configurations. And as yet another example, instructions carried in the PDSCH can activate / deactivate CSI-RS / CSI-IM configurations.

[0814] Depend on Figure 20 It can be seen that when the timing compensation of the uplink data by the network side or gNB is greater than or equal to... When the network receives a HARQ ACK / NACK from the UE for a command carried in the PDSCH, it will not be earlier than the effective time of the downlink signal configuration of that command. Therefore, the gNB will not be able to know in a timely manner whether the UE has correctly decoded the PDSCH or MACCE carrying that command. That is, when the MAC CE configuration for downlink data takes effect, the network has not yet received the UE's feedback HARQ ACK / NACK for the MAC CE. After the UE sends a HARQ ACK in time slot n, it will assume that the downlink time slot... The start command takes effect immediately, which can lead to different interpretations of the effective time of the command by the UE and gNB, causing communication conflicts. The timing compensation value for uplink data mentioned here represents the amount by which the network side or gNB delays the receive window when receiving uplink data.

[0815] To improve the above issues, a Koffset can be introduced based on the network-side timing compensation value for uplink data. The UE assumes that the downlink configuration takes effect at... Time slots, such as Figure 21 As shown, when an appropriate Koffset value is used (delaying the downlink signal configuration command's effective time to ensure that the command only takes effect after the gNB receives the corresponding ACK, i.e., the time length represented by Koffset should not be less than the time length represented by the network side's timing compensation value for uplink data), the gNB can make the downlink configuration command effective after receiving the HARQ ACK sent by the UE for the corresponding downlink configuration command, ensuring that both the UE and the gNB make the downlink configuration command effective in the same downlink time slot.

[0816] In this embodiment, Koffset can be obtained using the following formula:

[0817] For example:

[0818] Here, `time_compensated` is the timing compensation value applied by the network side to the uplink data sent by the UE. The unit can be seconds, milliseconds, microseconds, slot length, symbol length, or other time units. `time_compensate` is equivalent to `delay_compensated` mentioned above. The gNB can send the `Koffset` value to the UE. In this way, both the gNB and the UE obtain the `Koffset` value and can determine the effective time of the downlink signal configuration command based on the `Koffset` value.

[0819] Alternatively, gNB can also calculate Koffset using the following formula:

[0820]

[0821] Here, △K represents an integer agreed upon in the protocol to adjust the Koffset value (considering calculation errors and / or processing delays, etc.).

[0822] Alternatively, the gNB can send to the UE The UE and gNB determine the timing offset value Koffset_new based on the system error and / or processing delay.

[0823] Koffset_new = Koffset + △K

[0824] After receiving Koffset and ΔK, both the gNB and the UE obtain the effective time of the downlink signal configuration instruction based on Koffset_new. That is, the UE assumes that the downlink configuration takes effect on... Time slot.

[0825] Alternatively, the gNB can send the time_compensated value to the UE, and the UE and gNB can calculate the Koffset value to be used according to the formula:

[0826]

[0827] Optionally, when calculating Koffset, a fixed value can be added or subtracted from the calculation formula given in this application. For example, considering the differences in duplex modes (time-division duplex (TDD) and frequency-division duplex (FDD)) or the influence of network device location / positioning errors, a time offset value TA_offset can be added or subtracted when calculating Koffset. When using FDD, TA_offset = 0; when using TDD, TA_offset = 624. For example,

[0828] Alternatively, the gNB can send the time_compensated and ΔK values ​​to the UE, and the UE and gNB can calculate the Koffset value to be used according to the formula:

[0829]

[0830] Here, time_compensated can be a time quantity or a quantified time quantity. That is, the time unit of time_compensated can be determined according to the actual use case, and there is no limitation here.

[0831] Alternatively, the gNB can send the time_compensated and Δtiming_offset values ​​to the UE, and the UE and gNB can calculate the Koffset value to be used according to the formula:

[0832]

[0833] Among them, △timing_offset is the adjustment value of gNB to time_compensated to take into account processing delay and calculation error. It can be the amount of time or the quantized amount of time. That is, the time unit of △timing_offset can be determined according to the actual use case.

[0834] Alternatively, to save signaling overhead and reduce the number of bits of information transmitted related to Koffset, the gNB can send a timing offset difference ΔKoffset based on another time-related value (known to both the UE and gNB, such as a time-related value agreed upon by the gNB and UE, a time-related value sent by the gNB to the UE, or a time-related value sent by the UE to the gNB). The UE and gNB then calculate the Koffset to be used according to the agreed formula.

[0835]

[0836] Alternatively, you can directly calculate Koffset using the time_related parameter, i.e.

[0837]

[0838] Alternatively, the gNB can send a time difference component Δtiming (Δtiming is a time length value) based on another time-related quantity. The UE and gNB calculate the Koffset to be used according to the agreed formula, i.e.

[0839]

[0840] Alternatively, the gNB can transmit a scale factor S (S is a non-negative number) based on another time-related quantity, and the UE and gNB calculate the Koffset to be used according to an agreed formula, i.e.

[0841]

[0842] Alternatively, the gNB can jointly send ΔKoffset and / or Δtiming and / or S, and the UE and gNB calculate the Koffset to be used according to an agreed formula, for example...

[0843]

[0844] For example, the time_related parameter can be 2H / c or 4H / c, where H represents the satellite's orbital altitude (which the UE can obtain from the ephemeris information sent by the network side), and c represents the speed of light.

[0845] Alternatively, the `time_related` parameter can be a common timing advance (TA). The common timing advance can be obtained in, but is not limited to, the following ways: selecting a reference point (e.g., the point closest to the base station) within the beam or cell's coverage area and calculating the reference point-satellite distance; or, the round-trip time between the reference point, satellite, and ground station, with the common timing advance equal to this round-trip time or equal to this round-trip time plus / minus a fixed value (this fixed value accounts for the inaccuracy of satellite location information, processing delays, or the impact of the UE's altitude on TA usage; this fixed value is constant over a relative period and can be changed). The reference point can be a point on the serving link or a feeder link. Depending on the reference point's location, the transmitted common TA value may be positive, negative, or zero; this is not limited here. Similarly, the base station may also send the UE a reference point's location coordinates, and the UE calculates the common timing advance based on the round-trip time between the satellite's location and the reference point's location.

[0846] Alternatively, the `time_related` parameter can be existing timer or receive window parameters and combinations thereof in the methods and embodiments described above, because these timer durations and receive window durations are related to the round-trip time and processing latency of the UE and gNB. Furthermore, the gNB will send these parameters to the UE via broadcast, unicast, or other means, so that both the UE and gNB are aware of these timer durations and receive window durations. For example, some timer durations related to round-trip time may be agreed upon or sent between the UE and gNB, which can be used as or used to form the `time_related` parameter, as shown below:

[0847] The delay start duration (Timer offset) of the discontinuous receive downlink retransmission round-trip timer (drx-HARQ-RTT-TimerDL) is calculated as offset_of_drx-HARQ-RTT-TimerDL.

[0848] The delay start duration (Timer offset) of the discontinuous receive uplink retransmission round-trip timer (drx-HARQ-RTT-TimerUL) is calculated as offset_of_drx-HARQ-RTT-TimerUL.

[0849] The delay start time (Timer offset) of the random access contention resolution timer (ra-ContentionResolutionTimer) is offset_of_ra-ContentionResolutionTimer or RCR_offset.

[0850] Schedule request to disable timer (sr-ProhibitTimer) timer_sr-ProhibitTimer

[0851] Reassembly timer (t-Reassembly)

[0852] Discard Timer (timer_discardTimer)

[0853] The length of the receive window (ra-ResponseWindow) for receiving RAR (Random Access Response) signals is timer_ra-ResponseWindow.

[0854] The `time_related` parameter can include one or more of the parameters mentioned above. For example, the `time_related` parameter can be the time length represented by `offset_of_drx-HARQ-RTT-TimerDL`. After the UE receives the `ΔKoffset` sent by the gNB, both the gNB and the UE can calculate the `Koffset` to be used according to the following formula.

[0855]

[0856] Similarly, after the UE receives the S sent by the gNB, both the gNB and the UE can calculate the Koffset to be used according to the following formula.

[0857]

[0858] For example, the `time_related` parameter can be the sum of the time lengths represented by `offset_of_drx-HARQ-RTT-TimerDL` and `timer_t-Reassembly`. After the UE receives the `ΔKoffset` sent by the gNB, both the gNB and the UE can calculate the `Koffset` to be used according to the following formula.

[0859]

[0860] It is understandable that, according to the above description, "Since the base station needs to inform the UE not only of the duration of the RAR receiving window, but also of the delay start duration of the RAR receiving window, the first timing offset can also be determined based on the duration of the RAR receiving window and the delay start duration of the RAR receiving window." Therefore, Koffset can be calculated based on the sum of the time length represented by the duration of the RAR receiving window and the delay start duration of the RAR receiving window, i.e. This method also applies here. In addition, the method of obtaining Koffset using the above formula (10) or (11) also applies here, such as △Koffset_time or △Koffset can be equal to 0. Of course, △Koffset_time or △Koffset can be non-zero, which is not limited here.

[0861] It is understandable that, according to the above description, "Since the base station needs to inform the UE not only of the duration of the random access contention resolution timer, but also of the delay start duration of the random access contention resolution timer, the first timing offset can also be determined based on the duration of the random access contention resolution timer and the delay start duration of the random access contention resolution timer." Therefore, Koffset can be calculated based on the sum of the duration of the random access contention resolution timer and the delay start duration of the random access contention resolution timer, i.e. This method also applies here. Furthermore, the method for obtaining Koffset using equations (20) or (21) above also applies here.

[0862] Using the formulas, parameters, and methods described above and in the embodiments, different schemes for obtaining Koffset can be obtained, which will not be elaborated here.

[0863] To save signaling overhead and reduce the number of bits of information transmitted related to Koffset, the gNB and UE can agree on a formula to calculate Koffset using information already sent to the UE. 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 gNB can be explained by the following formula:

[0864] time_compensated=RTD(UE,gNB)-TA_related

[0865] Here, the TA_related parameter represents a parameter related to the TA value used by the UE. For example, TA_related can be equal to the TA value used by the UE. RTD(UE,gNB) is the round-trip time between the UE and gNB, or the round-trip time between the UE and the satellite. For example, the parameter RCR_offset represents the minimum round-trip time between gNB and the UE's beam / cell. The time length represented by RCR_offset can be substituted into RTD(UE,gNB) in the above formula to obtain the time_compensated value, and then the above formula can be used to calculate Koffset. For example, the formula... Alternatively, TA_related can represent the scheduling_offset, a timing offset used by the UE related to the uplink scheduling delay. When the UE receives an uplink scheduling command in time slot n, the UE transmits uplink data in time slot n+K2+scheduling_offset. Then, the time length represented by scheduling_offset can be replaced by TA_related and substituted into the above formula to obtain the time_compensated value. Subsequently, the above formula can be used to calculate Koffset. For example, using the formula... If we substitute the quantized value related to RTD(UE,gNB) (quantized using slot_duration) and the quantized value related to TA_related (quantized using slot_duration) into the above formula, we can directly obtain the Koffset value, because the time_compensated obtained at this time is also a quantized value based on slot_duration.

[0866] It is understood that the various parameters (including Koffset, Δ, time_compensated, Δtiming_offset, Δtiming, S, etc.) in the embodiments of this application can be broadcast to the terminal by the network device from at least one of the broadcast information including system information block (SIB) 1, other system information (OSI), and main system information block (MIB). They can also be sent to the terminal via unicast or multicast. If sent during the radio resource control (RRC) connection phase, the network device can carry or indicate this information in at least one of the following: RRC information, RRCReconfiguration message, downlink control information (DCI), group DCI, media access control (MAC) control element (CE), and timing advance command (TAC), or transmit it to the UE with data transmission or carried in a separately allocated PDSCH.

[0867] As described in the above embodiments: after the UE obtains the latest timing offset, i.e., the second timing offset, it can use the second timing offset to send base station scheduling data information or control channel information, etc., to the base station after the second timing offset takes effect. In the three methods described above, in Method 1, K1 is a value obtained from the PDSCH-to-HARQ-timing-indicator instruction index table (dl-DataToUL-ACK signaling transmission table) in the DCI. In Method 2, K2 = 0,…,32, and the value of K2 is indicated by the DCI instruction. Method 3 μ SRS When k = 0, the SRS signal subcarrier spacing is 15 kHz. The k value is configured by the slot offset parameter of the higher layer for each triggering of the SRS resource group.

[0868] In addition to the three methods described above, this application also provides several other methods, as shown below:

[0869] 1) PUSCH transmission timing scheduled by DCI

[0870] If the UE receives uplink grant / scheduling information in downlink time slot n, then the UE's PUSCH data must be stored in the uplink time slot. Send. Where K2 = 0,…,32, the value of K2 is indicated by the DCI instruction. μ PUSCH and μ PDCCH It is related to the subcarrier spacing of PUSCH and PDCCH, that is

[0871] Besides DCI, there is another way to schedule PUSCH: configured grant. This scheduling method also requires the use of Koffset, and the automatic Koffset update scheme of this invention can be used.

[0872] 2) RAR-authorized scheduling of PUSCH transmission timing

[0873] When the UE receives PDSCH data carrying RAR messages in downlink time slot n, the UE needs to send random access message 3 (Msg3) in uplink PUSCH time slot n+K2+Δ+Koffset, where Δ is a value agreed upon by the protocol.

[0874] 3) PUSCH transmission timing carrying CSI

[0875] When a UE receives a Channel State Information (CSI) request via DCI in downlink time slot n, the UE needs to transmit the CSI in uplink PUSCH time slot n+K+Koffset. The value of K is indicated by the DCI command.

[0876] 4) CSI Reference Resource Timing

[0877] When the UE needs to send a CSI report in uplink time slot n', the CSI reference resource needs to be in downlink time slot nn. CSI_ref -Koffset is sent to the UE. Among them, n CSI_ref It is a numerical value related to the type of CSI report, as agreed upon in the agreement. μ DL and μ UL Related to the uplink and downlink subcarrier spacing, i.e., downlink subcarrier spacing. Uplink

[0878] 5) MAC CE activation timer

[0879] The gNB receives an uplink HARQ-ACK in uplink time slot n corresponding to a PDSCH carrying a MAC-CE instruction. This MAC-CE instruction indicates the configuration of the downlink signal. The UE assumes that the MAC-CE instruction for the downlink configuration is effective in the downlink time slot. The first time slot afterwards. When the subcarrier spacing is 2 μ At 15kHz, the number of time slots contained in a subframe, where X is a non-negative integer agreed upon in the protocol or configured through parameters. For example, the configuration instructions for downlink signals carried by the MAC CE in the PDSCH can be resource configuration for downlink ZP CSI-RS, or deactivation of already active downlink ZP CSI-RS resource configuration.

[0880] The gNB receives an uplink HARQ-ACK corresponding to a PDSCH carrying a command in uplink time slot n. This command configures the uplink signal, and the UE assumes that the command for this uplink configuration is effective in the uplink time slot. The first time slot afterwards. When the subcarrier spacing is 2 μ At 15kHz, the number of time slots contained in a subframe, where X is a non-negative integer agreed upon in the protocol or configured through parameters. For example, instructions carried in the PDSCH can activate / deactivate SRS resource configurations.

[0881] It is understood that in the above embodiments, the initial timing offset can also be expressed as the first timing offset, Koffset1, or K. offset1 Equal representation. Koffset and K offset These can be understood as the same parameter; time_duration and slot_duration can also be understood as the same parameter, as can ΔKoffset and ΔK, etc. Furthermore, in the various embodiments described above, Koffset or timing offset can be understood as the initial timing offset or the updated timing offset, etc. Whether it is the initial timing offset or the updated timing offset depends on the specific circumstances of the specific embodiment. The aforementioned Max_RTD_beam can be understood as the maximum round-trip time between the UE and the base station within the beam coverage area.

[0882] It is understood that the execution order of updating and using the timing offset shown above is not limited in the embodiments of this application. For example, when a UE or network device sends a message for updating the timing offset, it may not send the message for updating the timing offset based on the timing offset. As another example, when a UE or network device sends a message based on the timing offset, that message may not include information indicating the updated timing offset. Figure 10a For example, when the UE sends an uplink message to the base station based on the second timing offset, the uplink message may not include the updated second timing offset.

[0883] It is understood that the above methods and embodiments are explained using four-step random access and two-step random access as examples. The above methods, such as the method for obtaining and updating the timing offset, are not limited to use in the random access step and can be used at any stage of communication. For example, the second message, third message, etc., described in this application can be replaced with a certain downlink message and a certain uplink message.

[0884] It is understood that the implementation methods not described in one embodiment can be referred to in other embodiments, etc., and will not be detailed here.

Claims

1. A communication method applied to a terminal side, characterized by, The method comprises: receiving a timing offset difference value; updating a timing offset according to the timing offset difference value to obtain an updated timing offset, wherein the updated timing offset is used to delay a time slot for sending uplink information.

2. The method of claim 1, wherein: the updated timing offset is equal to the timing offset minus the timing offset difference value; or the updated timing offset is equal to the timing offset plus the timing offset difference value.

3. The method according to claim 1 or 2, characterized in that, The timing offset before the updating is at least one of the following: a timing offset currently used by the terminal, a reference timing offset value, and an initial timing offset. The reference timing offset is a timing offset configured through a broadcast message.

4. The method of claim 3, wherein, 5. The method of any one of claims 1-4, wherein: the timing offset difference value is carried in a medium access control control element (MAC CE) message. The timing offset difference value occupies 6 bits in the MAC CE.

6. The method of claim 5, wherein, The timing offset is in units of time slots.

7. The method according to any one of claims 1 to 6, characterized in that, The method further comprises:

8. The method according to any one of claims 1 to 7, characterized in that, receiving downlink information at a time slot n, and determining a time slot for sending uplink information according to the time slot n, the updated timing offset, and a K value, wherein the K value is a value indicated by a network side. The method comprises:

9. A communication method applied to the network side, characterized in that, determining a timing offset difference value, wherein the timing offset difference value is used to update a timing offset to obtain an updated timing offset, and the updated timing offset is used to delay a time slot for sending uplink information; and sending the timing offset difference value.

10. The method of claim 9, wherein: the updated timing offset is equal to the timing offset minus the timing offset difference value; or the updated timing offset is equal to the timing offset plus the timing offset difference value. The timing offset before the updating is at least one of the following: a timing offset currently used by the terminal, a reference timing offset value, and an initial timing offset.

11. The method according to claim 9 or 10, characterized in that, The reference timing offset is a timing offset configured through a broadcast message.

12. The method of claim 11, wherein, 13. The method of any one of claims 9-12, wherein: the timing offset difference value is carried in a medium access control control element (MAC CE) message. The timing offset difference value occupies 6 bits in the MAC CE.

14. The method of claim 13, wherein, The timing offset is in units of time slots.

15. The method according to any one of claims 9-14, characterized in that, The apparatus comprises:

16. A communications device, characterized by a transceiver configured to receive a timing offset difference value; a processing unit configured to update a timing offset according to the timing offset difference value to obtain an updated timing offset, wherein the updated timing offset is used to delay a time slot for sending uplink information.

17. The apparatus of claim 16, wherein: the updated timing offset is equal to the timing offset minus the timing offset difference value; or the updated timing offset is equal to the timing offset plus the timing offset difference value. The timing offset before the updating is at least one of the following: a timing offset currently used by the terminal, a reference timing offset value, and an initial timing offset.

18. The apparatus of claim 16 or 17, wherein, The reference timing offset is a timing offset configured through a broadcast message. ​ 19. The apparatus of claim 18, wherein, ​ 20. The apparatus of any of claims 16-19, wherein the timing offset difference is carried in a medium access control control element (MAC CE) message. The timing offset difference occupies 6 bits in the MAC CE.

21. The apparatus of claim 20, wherein, The timing offset is in units of slots.

22. The apparatus of any of claims 16-21, wherein, 23. The apparatus of any of claims 17-22, wherein the transceiver is further configured to receive downlink information at a slot n, and the processing unit is further configured to determine a slot for transmitting uplink information based on the slot n, the updated timing offset, and a K value, the K value being a value indicated by a network side. comprising: a processing unit configured to determine a timing offset difference, the timing offset difference being used to update a timing offset to obtain an updated timing offset, the updated timing offset being used to delay a slot for transmitting uplink information; and a transceiver configured to transmit the timing offset difference.

24. A communications device, characterized by 25. The apparatus of claim 24, wherein the updated timing offset is equal to the timing offset minus the timing offset difference; or the updated timing offset is equal to the timing offset plus the timing offset difference. The timing offset before the update is at least one of: a timing offset currently used by the terminal, a reference timing offset value, and an initial timing offset. The reference timing offset is a timing offset configured through a broadcast message.

28. The apparatus of any of claims 24-27, wherein the timing offset difference is carried in a medium access control control element (MAC CE) message. The timing offset difference occupies 6 bits in the MAC CE.

26. The apparatus of claim 24 or 25, wherein, The timing offset is in units of slots.

27. The apparatus of claim 26, wherein, comprising a processor and a memory coupled to the processor; the memory is configured to store computer-executable instructions; the processor is configured to execute the computer-executable instructions stored in the memory to cause the communication apparatus to perform the method of any of claims 1-8; or the processor is configured to execute the computer-executable instructions stored in the memory to cause the communication apparatus to perform the method of any of claims 9-15.

29. The apparatus of claim 28, wherein, comprising a processor and an interface circuit; 30. The apparatus of any of claims 24-29, wherein, the interface circuit is configured to receive code instructions and transmit the code instructions to the processor; the processor executes the code instructions to cause the method of any of claims 1-8 to be performed; or the processor executes the code instructions to cause the method of any of claims 9-15 to be performed.

31. A communications device, characterized by The computer-readable storage medium is configured to store instructions that, when executed, cause the method of any of claims 1-8 to be implemented; or the computer-readable storage medium is configured to store instructions that, when executed, cause the method of any of claims 9-15 to be implemented. The instructions, when executed on the processor, cause the method of any of claims 1-8 to be implemented; or the instructions, when executed, cause the method of any of claims 9-15 to be implemented. ​ 32. A communications device, characterized by ​ ​ 33. A computer-readable storage medium, characterized in that, ​ 34. A computer program product comprising instructions, wherein: ​ 35. A communication system, characterized by including the apparatus of any one of claims 16-23 and the apparatus of any one of claims 24-30.

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