A communication method and apparatus

Abstract

The application provides a communication method and device. The method comprises the following steps: when a network device receives a first message from a terminal device in a first beam area, determining a first parameter value required by the terminal device to adjust a TA according to a round-trip time between the terminal device and the network device and a time delay compensation value of the first beam area, and then sending a second message to the terminal device. The first beam area is a coverage area of at least one first beam included in a first beam group; and the first parameter value is carried in the second message. Thus, the method can prevent time offset jump when the terminal device performs beam switching in the beam area corresponding to the same beam group, effectively reduces the frequency of time offset jump, and can align the time when the uplink data sent by the terminal device located in a single cell reaches the network device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and in particular to a communication method and device. BACKGROUND

[0002] In recent years, with the rapid development of mobile communication technology, the ground cellular network has basically covered the population-dense areas. However, in some special communication scenarios (such as the Gobi, desert, ocean, remote mountainous areas, etc.), the ground cellular network is difficult to completely cover. In addition, the ground infrastructure for providing the ground cellular network in some areas is damaged after being subjected to natural disasters such as floods, earthquakes, typhoons, snow disasters, etc., so that the ground cellular network in these areas cannot provide reliable network services, resulting in that the users in these areas cannot normally use the network. In order to solve this problem, the industry introduces a non-terrestrial network (Non-terrestrial Networks, NTN) to realize that the users in these areas can normally use the network. Among them, the NTN network includes a satellite communication network, a high altitude platform station (high altitude platform station, HAPS), and an air-to-ground network, and the NTN network has the characteristics of wide coverage and being not affected by the ground natural disasters, and can effectively complement the ground cellular network to provide more reliable communication services for users. Exemplarily, according to the different satellite orbit heights, the satellites can be divided into geostationary earth orbit (Geostationary Earth Orbit, GEO) satellites, middle earth orbit (Middle Earth Orbit, MEO) satellites, and low earth orbit (Low Earth Orbit, LEO) satellites.

[0003] However, in the random access stage in the satellite communication scenario, due to the long distance between the satellite and the terminal device (such as a smart phone), the round-trip delay between the satellite and the terminal device is large. For example, taking the LEO satellite as an example, the round-trip delay between the LEO satellite and the terminal device is greater than 6ms, and in the random access stage, since the cyclic prefix (Cyclic Prefix, CP) length contained in the random access preamble sent by the terminal device is limited, the network device (such as a base station) cannot correctly receive the random access preamble. At the same time, since the timing advance command (timing advance command, TAC) carried in the random access response (Random Access Response, RAR) sent by the network device has a limited length, the network device cannot indicate to adjust a too large delay, so that the time when the uplink data sent by the terminal device arrives at the network device cannot be aligned.

[0004] To solve the above problems, the following solutions are mainly used at present.

[0005] Solution one: In order to ensure that the terminal device can accurately access the network device in the satellite communication scenario, and the time of uplink data of the terminal device reaching the network device can be aligned, the network device sends ephemeris information to the terminal device, and the ephemeris information includes the coordinate position and orbit information of the satellite. After receiving the ephemeris information, the terminal device determines the round-trip delay between the satellite and the terminal device according to the position of the terminal device and the coordinate position of the satellite, and determines the timing advance (TA) required for the terminal device to send data according to the round-trip delay.

[0006] The above solution one needs to adjust the function configuration of each terminal device, that is, configure the function of obtaining the ephemeris information of the satellite for each terminal, which is not suitable for a large number of terminal devices.

[0007] Solution two: In order to ensure that the terminal device can accurately access the network device in the satellite communication scenario, and the time of uplink data of the terminal device reaching the network device can be aligned, the network device pre-compensates the time offset at the beam level, that is, the network device determines the round-trip delay between the network device and the beam center point of a certain beam according to the coverage position and coverage range of the beam on the ground, and takes the round-trip delay as the time delay compensation value corresponding to the beam. Then, the network device determines the parameter value required for the terminal device to adjust the TA according to the time delay compensation value and the estimated TA, and the parameter value is carried in the TAC. Then, the network device sends the RAR to the terminal device, and the RAR carries the TAC.

[0008] The above solution two uses the beam-level pre-compensation method, so that the time delay compensation values pre-compensated by different beams providing communication services for the terminal device at different times are different, resulting in the problem of time offset jump when the terminal device switches from one beam to another beam. Meanwhile, in the case of multiple beams in a single cell, if the TAs pre-compensated by multiple beams are different, the receiving times of multiple beams are different, resulting in that the time of uplink data sent by the terminal device reaching the network device is not aligned. SUMMARY

[0009] Embodiments of the present application provide a communication method and device to effectively reduce the frequency of time offset jump, and ensure that multiple beams in a single cell are scheduled in the same beam group, so that the time of uplink data (or uplink message or uplink signal, etc.) sent by the terminal device located in the single cell reaching the network device can be aligned.

[0010] In a first aspect, an embodiment of the present application provides a communication method, which can be executed by a network device or a component (such as a chip system or a circuit, etc.) capable of supporting functions required by the network device to implement the method. Optionally, taking the network device as an example, in the method, when the network device receives a first message from a terminal device in a first beam area, the network device can determine a first parameter value required by the terminal device to adjust a TA according to a round-trip time delay between the terminal device and the network device and a time delay compensation value of the first beam area; and then the network device can send a second message to the terminal device. The first beam area is a coverage area of at least one first beam included in a first beam group; the first message is used to indicate that the terminal device requests to access the network device in a random access process; the second message carries the first parameter value; and the second message is used to indicate a response of the network device to the request of the terminal device in the random access process.

[0011] In the above method, the network device can assign the same time delay compensation value to at least one beam included in the same beam group, so that the terminal device does not have a time offset jump when performing beam switching in the beam area corresponding to the same beam group, which helps to effectively reduce the frequency of time offset jump. The method can also implement scheduling of multiple beams in a single cell (i.e., the same cell) in the same beam group, so that the uplink data (or uplink message or uplink signal, etc.) sent by the terminal device located in the single cell can arrive at the network device at the same time. In addition, the above design does not need to adjust the functional configuration of multiple terminal devices, so the workload of adjusting the functional configuration of the terminal devices can be reduced.

[0012] In a possible design, for each beam group, the beam group needs to meet a corresponding beam grouping rule. Optionally, there are two possible forms of the beam grouping rule. For example, taking a first beam group as an example, a first beam grouping rule that needs to be met by the first beam group is that a difference between a maximum round-trip time delay corresponding to the first beam group and a minimum round-trip time delay corresponding to the first beam group is less than or equal to a first value, and / or the difference between the maximum round-trip time delay and the minimum round-trip time delay is less than or equal to a second value. A second beam grouping rule that needs to be met by the first beam group is that a difference between the maximum round-trip time delay corresponding to the first beam group and a third value is less than or equal to the first value, and / or the difference between the maximum round-trip time delay and the third value is less than or equal to the second value.

[0013] The first value is equal to the sum of the maximum adjustment length of the location area for carrying the first parameter value in the second message and the length of the cyclic prefix carried in the third message; the second value is the length of the cyclic prefix contained in the random access preamble carried in the first message; and the third value is equal to the sum of the minimum round trip delay corresponding to the first beam group and the length of the cyclic prefix carried in the third message; and the third message is from the terminal device.

[0014] In the above design, by setting the difference between the maximum round trip delay corresponding to the first beam group and the minimum round trip delay corresponding to the first beam group to be less than or equal to the first value, or the difference between the maximum round trip delay corresponding to the first beam group and the third value to be less than or equal to the first value, it can be ensured that the time offsets in the first beam group are all within the adjustable range after the first beam group is pre-compensated with the same time delay compensation value, and even if there is a residual time offset, it is also within the length of the CP contained in the third message, thereby ensuring that the network device can correctly receive the third message. By setting the difference between the maximum round trip delay and the minimum round trip delay to be less than or equal to the second value, or the difference between the maximum round trip delay and the third value to be less than or equal to the second value, it can be ensured that the network device can correctly receive the random access preamble from the terminal device, and ensure the correct performance of the subsequent process.

[0015] In a possible design, since there are two possible forms of beam grouping rules, there are also two possible implementation manners of determining the time delay compensation value. Optionally, taking the first beam area corresponding to the first beam group as an example, corresponding to the first beam grouping rule, the time delay compensation value of the first beam area is equal to the minimum round trip delay corresponding to the first beam group. Corresponding to the second beam grouping rule, the time delay compensation value of the first beam area is greater than 0 and less than or equal to the sum of the minimum round trip delay and the length of the cyclic prefix carried in the third message.

[0016] In the above design, the network device pre-compensates at least one beam belonging to the same beam group with the same time delay compensation value, which can ensure that there is no time offset jump phenomenon when the terminal device performs beam switching within the same beam group, and can realize that multiple beams at the same time can only be scheduled in the same beam group in parallel, thereby ensuring that the uplink data (or uplink message or uplink signal, etc.) sent by the terminal device located in the area covered by the same beam group can be aligned in time when reaching the network device.

[0017] In a possible design, after the network device sends the second message to the terminal device located in the first beam area, when the terminal device located in some beam area (such as the first beam area) successfully establishes a communication connection with the network device, the network device can adjust the TA required for the terminal device located in some beam area to send the uplink message, so as to align the time when the uplink data sent by the terminal devices located in different beam areas reaches the network device in the data transmission stage.

[0018] For example, taking the terminal device located in the first beam area as an example, the terminal device successfully accesses the network device, and the network device can send a fourth message to the terminal device. The fourth message carries a second parameter value required for the terminal device to adjust the TA, and the second parameter value is determined by the network device according to the difference between the uplink message receiving time corresponding to the first beam area and the uplink message receiving time corresponding to the second beam area. The second beam area is the coverage area of at least one second beam included in the second beam group.

[0019] In the design, the network device sends the fourth message to the terminal device located in the first beam area, so as to facilitate the terminal device to timely and accurately adjust the TA, thereby achieving that the time when the uplink data (or uplink message or uplink signal, etc.) sent by the terminal devices located in multiple different beam areas reaches the network device can be aligned, and thereby the flexibility of beam scheduling in the data transmission stage can be improved.

[0020] In a possible design, before the network device receives the first message from the terminal device located in the first beam area, the network device can first divide the multiple beams corresponding to the network device into at least one beam group. The at least one beam group includes the first beam group, and each beam group corresponds to a beam area.

[0021] In the design, the network device divides the multiple beams corresponding to the network device into at least one beam group, so that the at least one beam included in the same beam group is pre-compensated with the same time delay compensation value. This can prevent time offset jump when the terminal device performs beam switching in the beam area corresponding to the same beam group, can effectively reduce the frequency of time offset jump, and can divide multiple beams belonging to the same cell (i.e., a single cell) in the same beam group. This can help to ensure that the multiple beams in the single cell are scheduled in the same beam group, so that the time when the uplink data (or uplink message or uplink signal, etc.) sent by the terminal device located in the single cell reaches the network device can be aligned.

[0022] In a second aspect, an embodiment of the present application provides a communication method, which can be executed by a terminal device or a component (such as a chip system or a circuit, etc.) capable of supporting functions required by the terminal device to implement the method. Optionally, taking the terminal device as an example, in the method, the terminal device can send a first message to a network device, where the first message is used to indicate that the terminal device requests to access the network device, and the terminal device is located in a first beam area. When the terminal device receives a second message from the network device, the terminal device can adjust a TA required by the terminal device to send a first uplink message according to a first parameter value carried in the second message. The second message is used to indicate a response of the network device to the request of the terminal device in a random access process, and the first parameter value is determined by the network device according to a round trip time (RTT) between the terminal device and the network device and a time delay compensation value of the first beam area. The first beam area is a coverage area of at least one first beam included in a first beam group, and the first uplink message is used to indicate an uplink message sent by the terminal device after the second message.

[0023] In the above design, by allocating the same time delay compensation value to at least one beam included in the same beam group, the terminal device can not have a time offset jump when performing beam switching in the beam area corresponding to the same beam group, which helps to effectively reduce the frequency of time offset jump and implement scheduling of multiple beams in a single cell (i.e., the same cell) in the same beam group, so that the uplink data (or uplink message or uplink signal, etc.) sent by the terminal device located in the single cell can be aligned in time when reaching the network device. In addition, the above design does not need to adjust the functional configuration of the multiple terminal devices, so the workload of adjusting the functional configuration of the terminal devices can be reduced.

[0024] In a possible design, for each beam group, the beam group needs to meet a corresponding beam grouping rule. Optionally, there are two possible forms of the beam grouping rule. For example, taking a first beam group as an example, a first beam grouping rule that needs to be met by the first beam group is that a difference between a maximum RTT corresponding to the first beam group and a minimum RTT corresponding to the first beam group is less than or equal to a first value, and / or the difference between the maximum RTT and the minimum RTT is less than or equal to a second value. A second beam grouping rule that needs to be met by the first beam group is that a difference between the maximum RTT corresponding to the first beam group and a third value is less than or equal to the first value, and / or the difference between the maximum RTT and the third value is less than or equal to the second value.

[0025] The first value is equal to the sum of the maximum adjustment length of the location area in the second message for carrying the first parameter value and the length of the cyclic prefix carried in the third message; the second value is the length of the cyclic prefix contained in the random access preamble carried in the first message; and the third value is equal to the sum of the minimum round trip delay corresponding to the first beam group and the length of the cyclic prefix carried in the third message; and the third message is from the terminal device.

[0026] In the above design, by setting the difference between the maximum round trip delay corresponding to the first beam group and the minimum round trip delay corresponding to the first beam group to be less than or equal to the first value, or the difference between the maximum round trip delay corresponding to the first beam group and the third value to be less than or equal to the first value, it can be ensured that the time offsets in the first beam group are all within the adjustable range after the first beam group is pre-compensated with the same time delay compensation value, and even the residual time offset is also within the length of the CP contained in the third message, thereby ensuring that the network device can correctly receive the third message. By setting the difference between the maximum round trip delay and the minimum round trip delay to be less than or equal to the second value, or the difference between the maximum round trip delay and the third value to be less than or equal to the second value, it can be ensured that the network device can correctly receive the random access preamble from the terminal device, and ensure the correct progress of the subsequent process.

[0027] In a possible design, after the terminal devices in some beam areas (such as the first beam area) adjust the TA required for the terminal devices to send the first uplink message, when the terminal devices in some beam areas successfully establish a communication connection with the network device, in order to align the time when the uplink data sent by the terminal devices in different beam areas reaches the network device in the data transmission stage, the network device can adjust the TA required for the terminal devices in some beam areas to send the uplink message accordingly.

[0028] Exemplarily, taking a terminal device located in the first beam area as an example, the terminal device successfully accesses the network device, and the terminal device can receive a fourth message from the network device and adjust the TA of the terminal device according to a second parameter value carried in the fourth message and required for the terminal device to adjust the TA. The second parameter value is determined by the network device according to the difference between the uplink message receiving time corresponding to the first beam area and the uplink message receiving time corresponding to the second beam area, and the second beam area is the coverage area of at least one second beam included in the second beam group.

[0029] In the design, the network device can send the fourth message to the terminal device in the first beam area, so that the terminal device can adjust the TA in time and accurately, and thus the uplink data (or uplink message or uplink signal, etc.) sent by the terminal devices in the multiple different beam areas can arrive at the network device at the same time, thereby helping to improve the flexibility of beam scheduling in the data transmission stage.

[0030] In a third aspect, an embodiment of the present application provides a communication apparatus. Optionally, the communication apparatus can be a communication device (such as a network device or a terminal device), or can also be a chip or the like arranged in a communication device (such as a network device or a terminal device). In one example, when the communication apparatus is used to implement the function of the network device in the communication method embodiment provided by the present application, the beneficial effects can be referred to the description of the first aspect, which will not be repeated here. The communication apparatus has the function of implementing the behaviors in the method embodiments of the first aspect. The function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In a possible design, the communication apparatus includes a communication module and a processing module. The processing module is configured to, when receiving a first message from a terminal device in a first beam area, determine a first parameter value required by the terminal device to adjust a TA according to a round-trip delay between the terminal device and the network device and a time delay compensation value of the first beam area. The first beam area is a coverage area of at least one first beam included in a first beam group, and the first message is used to indicate that the terminal device requests to access the network device in a random access process. The communication module is configured to send a second message to the terminal device. The first parameter value is carried in the second message, and the second message is used to indicate a response of the network device to the request of the terminal device in the random access process. These modules can perform the corresponding functions in any possible implementation design of the first aspect, and the specific implementation can be referred to the detailed description in the method embodiments, which will not be repeated here.

[0031] In another example, when the communication device is used to implement the functions of the terminal device in the communication method embodiments provided in this application, the beneficial effects can be found in the description of the second aspect, which will not be repeated here. The communication device has the function of implementing the behavior in the method examples of the second aspect described above. The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In one possible design, the communication device includes a communication module and a processing module. The communication module is used to send a first message to the network device. The first message indicates that the terminal device requests access to the network device, and the terminal device is located within a first beam area. The communication module is also used to receive a second message from the network device. The second message carries a first parameter value and indicates the network device's response to the terminal device's request during random access. The processing module is used to adjust the TA required for the terminal device to send a first uplink message based on the first parameter value. The first parameter value is determined by the network device based on the round-trip delay between the terminal device and the network device, and the delay compensation value of the first beam area. The first beam area is the coverage area of ​​at least one first beam included in the first beam group. The first uplink message is used to indicate an uplink message sent by the terminal device after the second message. These modules can perform the corresponding functions in any possible implementation design of the second aspect described above, as detailed in the method examples, and will not be repeated here.

[0032] Fourthly, embodiments of this application provide a network device, which includes a first transceiver and a first processor. Optionally, the network device further includes a first memory. The first memory is used to store computer programs or instructions. The first processor is coupled to the first memory and the first transceiver. When the first processor executes the computer program or instructions, it causes the network device to perform any of the possible design methods described in the first aspect.

[0033] Fifthly, embodiments of this application provide a terminal device, which includes a second transceiver and a second processor. Optionally, the terminal device further includes a second memory. The second memory is used to store computer programs or instructions. The second processor is coupled to the second memory and the second transceiver. When the second processor executes the computer program or instructions, it causes the terminal device to perform any of the possible design methods described in the second aspect above.

[0034] Sixthly, embodiments of this application provide a communication system comprising a network device and a terminal device. The network device is used to implement the method in any possible design of the first aspect described above, and the network device is used to implement the method in any possible design of the second aspect described above.

[0035] In a seventh aspect, an embodiment of the present application provides a computer program product, which comprises a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer program or instructions cause the computer to perform the method in any possible design of the first aspect or the method in any possible design of the second aspect.

[0036] In an eighth aspect, an embodiment of the present application provides a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer program or instructions cause the computer to perform the method in any possible design of the first aspect or the method in any possible design of the second aspect.

[0037] In a ninth aspect, an embodiment of the present application further provides a chip, which is coupled with a memory, and the chip is used to read the computer program stored in the memory and execute the method in any possible design of the first aspect or the method in any possible design of the second aspect.

[0038] In a tenth aspect, an embodiment of the present application further provides a chip system, which comprises a processor, and the processor is used to support a computer device to implement the method in any possible design of the first aspect or the method in any possible design of the second aspect. In a possible design, the chip system further comprises a memory, and the memory is used to save the necessary program and data of the computer device. The chip system can be composed of a chip, or can contain a chip and other discrete devices.

[0039] On the basis of the implementation manners of the aspects provided in the present application, further combinations can be made to provide more implementation manners. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 FIG. 1 shows a schematic diagram of a satellite system according to an embodiment of the present application;

[0041] Figure 2 FIG. 2 shows a schematic diagram of a satellite system according to another embodiment of the present application;

[0042] Figure 3 FIG. 3 shows a flowchart of a communication method according to an embodiment of the present application;

[0043] Figure 4 FIG. 4 shows a schematic diagram of a beam grouping according to an embodiment of the present application;

[0044] Figure 5 FIG. 5 shows a flowchart of another communication method according to an embodiment of the present application;

[0045] Figure 6 Fig. 1 shows a schematic diagram of a time interval for a base station to transmit downlink data and receive uplink data according to an embodiment of the present application;

[0046] Figure 7 Fig. 2 shows a schematic diagram of a possible communication device according to an embodiment of the present application;

[0047] Figure 8 Fig. 3 shows a schematic diagram of a possible network device according to an embodiment of the present application;

[0048] Figure 9 Fig. 4 shows a schematic diagram of a possible terminal device according to an embodiment of the present application. DETAILED DESCRIPTION

[0049] Before introducing the technical solutions provided by the present application, first, some terms involved in the present application are explained and described so as to facilitate understanding by those skilled in the art.

[0050] (1) NTN refers to a network established using non-terrestrial communication technology, which can include but is not limited to a network that uses resources on a communication platform such as a satellite platform, an unmanned aerial vehicle (UAV) platform, or a high-altitude communication platform (HAPS) to provide communication services.

[0051] For example, NTN can include but is not limited to a satellite system, a UAV communication system, and a HAPS system. According to the height of the satellite from the earth's surface (i.e., the satellite orbit height), the satellite system can be divided into a geostationary orbit (GEO) satellite system, a medium earth orbit (MEO) satellite system, and a low earth orbit (LEO) satellite system.

[0052] Compared with a terrestrial communication network, NTN has the characteristics of wider coverage, higher path loss, larger delay, faster speed, and lower cost. With the increasing popularity of NTN research, the 3rd generation partnership project (3GPP) has also conducted standardization research on NTN, aiming to supplement or enhance the communication performance of the mobile communication system through the construction of NTN.

[0053] (2) network device, which can refer to any kind of device with wireless transceiver function. In the embodiments of the present application, the network device can include but is not limited to: an evolved NodeB (such as NodeB or eNB or e-NodeB) in a long term evolution (LTE) communication system, a base station (such as gNodeB or gNB) or a transmission receiving point (TRP) in a 5th generation (5G) new radio (NR) communication system, a base station in a subsequent evolution of 3GPP, an access node in a wireless-fidelity (WiFi) system, a wireless relay node or a wireless backhaul node, etc. Optionally, the base station can be a macro base station, a micro base station, a pico base station, a small station, a relay station, a balloon station, a gateway station (or called ground station, earth station, gateway station) or a satellite station, etc. Optionally, the base station can include one or more co-sited or non-co-sited TRPs.

[0054] Optionally, in some embodiments, the network device can also be a wireless controller in a cloud radio access network (CRAN) scenario, a centralized unit (CU) or a distributed unit (DU).

[0055] Optionally, in a network structure, the network device can include a CU node and a DU node. This structure can split the protocol layers of the network device, with part of the protocol layer functions being centrally controlled by the CU, and the rest of the protocol layer functions being distributed in the DU and controlled by the CU.

[0056] For example, the PDCP layer and the protocol layer above it can be arranged in the CU, and the protocol layer below the PDCP (such as the RLC layer and the MAC layer, etc.) can be arranged in the DU. It should be noted that this protocol layer division is only an example, and other protocol layer divisions can also be used. The radio frequency device can be remote or integrated in the DU, or partially remote and partially integrated in the DU, and the embodiments of the present application do not make any limitation. In addition, in some embodiments, the control plane (CP) and the user plane (UP) of the CU can be separated and implemented by different entities, which are respectively the control plane CU entity (CU-CP entity) and the user plane CU entity (CU-UP entity).

[0057] In the network architecture, signaling generated by the CU can be sent to the terminal device through the DU, or signaling generated by the terminal device can be sent to the CU through the DU. The DU can directly transmit the signaling to the terminal device or the CU through protocol layer encapsulation without parsing the signaling. In the network architecture, the CU is divided into a network device on the radio access network (RAN) side, and in addition, the CU can also be divided into a network device on the core network (CN) side, which is not limited by the present application.

[0058] Optionally, in some embodiments, the network device can also be a server, a wearable device, or a vehicle-mounted device, etc.

[0059] Exemplarily, the network device is taken as a base station for example. The plurality of network devices can be the same type of base station, or can be different types of base stations. The base station can communicate with the terminal device, or can communicate with the terminal device through a relay station. Optionally, the terminal device can communicate with a plurality of network devices carrying different communication technologies, for example, the terminal device can communicate with a base station carrying a base station supporting an LTE network, and can also communicate with a base station carrying a base station supporting a 5G network, and can also support dual connectivity with the base station carrying the LTE network and the base station carrying the 5G network.

[0060] (3) The terminal device is a device with wireless transceiver function. Optionally, the terminal device can be deployed on land, including indoor or outdoor, handheld, wearable or vehicle-mounted, or can also be deployed on the water surface (such as ships, etc.), or can also be deployed in the air (such as airplanes, balloons or satellites, etc.).

[0061] Exemplarily, the terminal device can be a mobile phone, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a vehicle-mounted terminal device, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home or a wearable terminal device, etc.

[0062] Optionally, the terminal device can also be referred to as a terminal, a user equipment (UE), an access terminal device, a vehicle-mounted terminal, an industrial control terminal, a UE unit, a UE station, a mobile station, a mobile station (MS), a mobile terminal (MT), a remote station, a remote terminal device, a mobile device, a UE terminal device, a terminal device, a wireless communication device, a UE agent, or a UE apparatus, etc. In the present application, the terminal device can be fixed in position or mobile, and the present application does not limit this.

[0063] (4) Core network (CN), responsible for terminal device registration, mobility management, session management, etc. Optionally, the core network has multiple functional units, which can be divided into control plane and data plane functional entities. The access and mobility management unit (AMF) is used to manage user access, security authentication, and mobility management. The user plane functional unit (UPF) is used to manage user plane data transmission, traffic statistics, and other functions. The session management function unit (SMF) is used to complete UE IP address allocation, UPF selection, charging and quality of service (QoS) policy control, etc. The policy control function unit (PCF) is used to manage charging policies and QoS policies. The network exposure function unit (NEF) is used to expose the services and capabilities of 3GPP network functions to the application function unit (AF), and also allows the AF to provide information to the 3GPP network function.

[0064] (5) Beam refers to the main lobe of the directional array diagram. Optionally, the network device (such as a base station) can adjust the weight of the antenna so that the satellite beam can point to different directions and have different coverage ranges. In the present application, the coverage range of the beam refers to the coverage range of the beam on the ground. For example, the coverage range of the beam can contain at least one location point. As the satellite moves and the weight is adjusted, the coverage range of the beam will also change.

[0065] (6) Random access preamble, used for terminal device to inform network device (such as base station) that there is a random access request, and enable the base station to estimate the transmission delay between the terminal device and the terminal device, so that the base station can calibrate the uplink timing and inform the terminal device through TAC. Optionally, the physical layer random access preamble is composed of a cyclic prefix (CP) and a data part (sequence, Seq).

[0066] In the LTE communication system, the parameters of several random access preamble formats can be seen in Table 1.

[0067] Table 1

[0068] Random access preamble format [TECHNICAL FIELD] CP ]] T Seq ]]> 0 3168*Ts 24576*Ts 1 21024*Ts 24576*Ts 2 6240*Ts 2*24576*Ts 3 21024*Ts 2*24576*Ts 4 (see Note) 448*Ts 4096*Ts

[0069] Wherein, T CP represents the time domain length of CP, T Seq represents the time domain length of Seq, Ts = 1 / (15k*2048) = 1 / 30720000s = 32.55208ns.

[0070] In the NR communication system, the parameters of several random access preamble formats can be seen in Table 2 and Table 3. Table 2 is for L RA = 839 and Δf RA ∈{1.25,5}kHz random access preamble. Table 3 is for L RA ∈{139,571,1151} and Δf RA = 15*2 u kHz random access preamble, wherein u represents subcarrier configuration, u ∈{0,1,2,3,5,6}.

[0071] Table 2

[0072]

[0073] Table 3

[0074]

[0075]

[0076] Wherein, N CP RA represents the time domain length of CP, κ = Ts / Tc = 64, Tc = 1 / (480k*4096) = 0.5086ns, taking the random access preamble format 0 as an example, N CPRA = 3168K*Tc; L RA denotes the sequence length of the random access preamble; Δf RA denotes the subcarrier spacing of the random access preamble; N u denotes the time domain length of Seq.

[0077] (7) Round-trip time (RTT) refers to the round-trip time between two locations where devices communicate, or can also refer to the round-trip time between two points. For example, taking a terminal device and a network device as an example, assuming that the distance between the location A where the terminal device is located and the location B where the network device is located is Sab, then RTT = Sab*2 / speed of electromagnetic wave propagation.

[0078] (8) Radio resource control (RRC) connection state, in a communication system, the RRC connection state of a terminal device includes three types: RRC connected (RRC_connected, referred to as connected state), RRC idle (RRC_idle, referred to as idle state), and RRC inactive (RRC_inactive, referred to as inactive state). Among them, the RRC idle state and the RRC inactive state can be collectively referred to as the RRC non-connected state.

[0079] When the terminal device is in the idle state, the RRC connection between the terminal device and the network device is released, and the network device and the terminal device no longer save the terminal device context information. The terminal device can receive the broadcast information (such as system information) and the paging message sent by the network device.

[0080] When the terminal device is in the inactive state, the RRC connection between the terminal device and the network device is suspended, but the terminal device and the terminal device continue to save the context information of the terminal device. When the terminal device enters the connected state from the inactive state, the network device and the terminal device can quickly recover the RRC connection between the terminal device and the network device based on the saved context information of the terminal device, so that the terminal device can quickly recover to the connected state.

[0081] When the terminal device is in the connected state, the RRC connection exists between the terminal device and the network device, and the two can communicate based on the RRC connection.

[0082] (9) Synchronization signal block (SSB), which is periodically sent by a network device and used for terminal device cell search process to achieve time-frequency synchronization with the network device.

[0083] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0084] The communication method provided by the embodiments of the present application can be applied to a communication system comprising a terminal device and a network device, for example, in an NTN. Exemplarily, the present application takes a satellite system in an NTN as an example for illustration. According to the communication mode of the satellite, the satellite system can be divided into a bent pipe mode and a regenerative mode.

[0085] Figure 1 Exemplarily, the satellite system schematic diagrams of the two bent pipe modes provided by the embodiments of the present application are shown. In Figure 1 In the satellite system shown, the satellite (which can also be referred to as a high altitude platform station (HAPS), a high altitude vehicle, or a satellite base station, etc.) only acts as a frequency converter and repeater, and the signal is generated and transmitted by a satellite ground station.

[0086] For example, as shown in a of Figure 1 The satellite can access the network using a non-3GPP radio protocol. The communication connection between the terminal device and the satellite, and between the satellite and the satellite ground station, is established through a non-3GPP radio protocol interface. The satellite ground station can comprise an access point, and the satellite ground station and the CN can communicate with each other through an Ng interface (such as an N2 interface, an N3 interface, etc.), and the CN and the data network (DN) can communicate through an N6 interface.

[0087] Figure 1 The difference between b of and a of Figure 1 is that the satellite can access the network through a 3GPP radio protocol. As shown in b of Figure 1 The satellite ground station is a base station, and the satellite can be equivalent to a repeater. The satellite can establish a communication connection with the satellite ground station through a Uu interface (or air interface), and the terminal device and the satellite can establish a communication connection through other transceivers. The interfaces between the satellite ground station, the CN and the DN are the same as those in a of Figure 1 The same places can be referred to each other, and here will not be repeated.

[0088] Figure 2 Exemplarily, the satellite system schematic diagrams of the two regenerative modes provided by the embodiments of the present application are shown. In Figure 2 In the satellite system shown, the satellite can carry a base station or a DU in the base station. The satellite can understand and process the signals received from the ground, and transmit the processed signals to the terminal device to realize signal regeneration.

[0089] For example, as shown in a of Figure 2As shown in a of FIG. 1, the satellite is equipped with a base station, and the satellite ground station also contains a base station. The terminal device and the satellite can establish a communication connection through a Uu interface, and the satellite and the satellite ground station can establish a communication connection through an Xn interface. The interfaces between the satellite ground station, the CN, and the DN are the same as those in a of FIG. 1, which can be mutually referred to and will not be repeated here. Figure 1 As shown in a of FIG. 1, the satellite system shown in a of FIG. 1 can also be a satellite system without a base station. In this case, the satellite ground station does not contain a base station. Figure 2 As shown in a of FIG. 1, the satellite system shown in a of FIG. 1 can also be a satellite system without a base station. In this case, the satellite ground station does not contain a base station.

[0090] As shown in b of FIG. 1, the satellite is equipped with a DU in the base station, and the satellite ground station contains a CU in the base station. The terminal device and the satellite can establish a communication connection through a Uu interface, and the satellite and the satellite ground station can establish a communication connection through an F1 interface. The interfaces between the satellite ground station, the CN, and the DN are the same as those in a of FIG. 1, which can be mutually referred to and will not be repeated here. Figure 2 As shown in b of FIG. 1, the satellite system shown in b of FIG. 1 can also be a satellite system without a base station. In this case, the satellite ground station does not contain a CU in the base station. Figure 1 As shown in b of FIG. 1, the satellite system shown in b of FIG. 1 can also be a satellite system without a base station. In this case, the satellite ground station does not contain a CU in the base station.

[0091] It should be noted that the satellite ground station in the satellite system shown in Figure 1 , Figure 2 may also be referred to as a gateway, a ground station, and an earth station, and is used to access the satellite to the network. In addition, the satellite and the satellite ground station in the above satellite system can also be referred to as network devices.

[0092] It should be noted that Figure 1 , Figure 2 only one satellite and one satellite ground station are shown, and in actual scenarios, multiple satellites and / or multiple satellite ground stations can be adopted according to needs. Each satellite can provide communication services to one or more terminal devices, each satellite ground station can correspond to one or more satellites, and each satellite can correspond to one or more satellite ground stations, which are not limited in the embodiments of the present application.

[0093] It should be noted that the satellite shown in Figure 1 or Figure 2 does not constitute a limitation of the communication system applicable to the embodiments of the present application. Therefore, the communication method provided by the embodiments of the present application can also be applicable to various communication systems, such as various NTN systems, LTE communication systems, 5G communication systems (also referred to as 5G NR systems), 6th Generation (6G) communication systems, and future communication systems.

[0094] In addition, the embodiments of the present application also do not limit the names of the devices in the communication system. For example, the satellite ground station can also have other names in different communication systems or communication scenarios.

[0095] As described in the background, the time delay compensation values provided by the existing scheme for different beams providing communication services for the terminal device at different times are different, resulting in a time offset jump problem when the terminal device switches from one beam to another. In view of this, the present application provides a communication method to effectively reduce the frequency of time offset jumps.

[0096] Based on the satellite system shown in Figure 1 or Figure 2 , the specific implementation of the communication method in the embodiments of the present application is described in detail.

[0097] Figure 3 An exemplary flowchart of a communication method provided by the embodiments of the present application is shown. The method is applicable to Figure 1 or Figure 2 the satellite system shown. The method flow can be implemented by data interaction between the terminal device and the network device. Optionally, the terminal device can be Figure 1 the terminal device shown or a component (such as a chip or integrated circuit) that can support the terminal device to implement the functions required by the method, or it can also be Figure 2 the terminal device shown or a component (such as a chip or integrated circuit) that can support the terminal device to implement the functions required by the method. The network device can be Figure 1 the network device (such as a satellite ground station or a base station) shown or a component (such as a chip or integrated circuit) that can support the network device to implement the functions required by the method, or it can also be Figure 2 the network device (such as a base station or a CU in a base station) shown or a component (such as a chip or integrated circuit) that can support the network device to implement the functions required by the method. In order to facilitate the introduction of the technical solutions provided by the embodiments of the present application, the flow of the communication method is implemented by data interaction between the network device and the terminal device. As shown in Figure 3 , the method comprises:

[0098] Step 301: The terminal device sends a first message to the network device.

[0099] Optionally, in the embodiments of the present application, the network device can divide a plurality of beams corresponding to the network device into at least one beam group according to a preset beam grouping rule, and the at least one beam group includes a first beam group.

[0100] For example, taking the network device as a satellite (also known as HAPS, high-altitude flying object or satellite base station, etc.), a satellite ground station (such as a base station), for example, the satellite can provide communication services to the terminal device located in the coverage area of the satellite, and the satellite can also be connected to the core network device.

[0101] When the communication mode of the satellite is the transparent mode, the satellite ground station can act as a base station of wireless communication, and the satellite can act as a relay of these base stations, and can transparently transmit signals between the satellite ground station and the terminal device.

[0102] Optionally, before the terminal device located in the satellite coverage area randomly accesses the satellite ground station, the satellite ground station can group a plurality of beams generated by the satellite according to a preset beam grouping rule to obtain at least one beam group, wherein each beam group contains at least one beam. Optionally, the area covered by the at least one beam contained in each beam group can be used as a beam area, that is, one beam group corresponds to one beam area, so as to form at least one beam area. For example, taking the first beam group as an example, the area covered by the at least one first beam contained in the first beam group can be used as the first beam area. Illustratively, the at least one beam belonging to the same beam group has the same time delay compensation value, and the same time delay compensation value is the time delay compensation value of the same beam group. For example, taking the first beam group as an example, the at least one first beam contained in the first beam group has the same time delay compensation value.

[0103] When the communication mode of the satellite is the regenerative mode, the satellite can act as a base station of wireless communication, for example, taking a man-made satellite as an example, a base station (such as a 5G base station) is deployed on the man-made satellite, and the satellite ground station can transparently transmit signaling between the man-made satellite and the core network.

[0104] Optionally, before the terminal device located in the satellite coverage area randomly accesses the satellite, the satellite can group a plurality of beams generated by the satellite according to a preset beam grouping rule to obtain at least one beam group, wherein each beam group contains at least one beam. Optionally, the area covered by the at least one beam contained in each beam group can be used as a beam area, so as to form at least one beam area.

[0105] Illustratively, the above-mentioned preset beam grouping rule has the following two possible implementation manners.

[0106] In the first mode, the first beam group is taken as an example. A difference between a maximum round trip time corresponding to the first beam group and a minimum round trip time corresponding to the first beam group is less than or equal to a first value, and / or, the difference between the maximum round trip time corresponding to the first beam group and the minimum round trip time corresponding to the first beam group is less than or equal to a second value. Optionally, the maximum round trip time corresponding to the first beam group can be a round trip time between a position point farthest from the network device in the first beam area and a position point where the network device is located, the minimum round trip time corresponding to the first beam group can be a round trip time between a position point closest to the network device in the first beam area and the position point where the network device is located, the first value is equal to a sum of a maximum adjustment length of a position area for carrying the first parameter value in the second message and a length of a cyclic prefix carried in the third message, and the second value is a length of a cyclic prefix included in a random access preamble carried in the first message. Optionally, the second message can come from the network device, and the third message can come from the terminal device. For example, the third message can be used to indicate that the terminal device requests to establish an RRC connection with the network device in the random access process.

[0107] For example, the preset beam grouping rule in the first mode can satisfy the following form:

[0108] (1) max(RTT)-min(RTT)≤RAR’+Msg3_CP, and / or, (2) max(RTT)-min(RTT)≤randomaccess preamble_CP;

[0109] Wherein, max(RTT) represents a maximum round trip time corresponding to a certain beam group, min(RTT) represents a minimum round trip time corresponding to the beam group, RAR’ represents a maximum adjustment length of a position area for carrying the first parameter value in the second message in the random access process (such as a maximum time offset of TAC that can be adjusted in the second message), Msg3_CP represents a length of a CP carried in a third message (Msg3) sent by the terminal device, and random access preamble_CP represents a length of a CP included in a random access preamble carried in the first message sent by the terminal device.

[0110] Optionally, the network device (such as a satellite) can group a plurality of beams generated by the satellite according to the formula (1) in the first mode, so as to ensure that time offsets in a certain beam group are all within an adjustable range after the same time delay compensation value is pre-compensated, and even if there is a residual time offset, it is also within the length of the CP included in the Msg3, so as to ensure that the network device can correctly receive the Msg3. The network device can group a plurality of beams generated by the satellite according to the formula (2) in the first mode, so as to ensure that the network device can correctly receive the random access preamble from the terminal device, and ensure the correct performance of the subsequent process.

[0111] Optionally, different beam groups in the first mode pre-compensate different time delay compensation values, and at least one beam belonging to the same beam group pre-compensates the same time delay compensation value. For example, the time delay compensation value of each beam group can be equal to the minimum round trip time corresponding to the beam group, i.e., the time delay compensation value of each beam group = min (at least one RTT corresponding to the beam group). In this way, for the same beam group, since the at least one beam included in the beam group pre-compensates the same time delay compensation value, when a certain terminal device switches between the at least one beam included in the beam group, there will be no time offset jump phenomenon, but only time offset jump phenomenon between different beam groups, thereby greatly reducing the frequency of time offset jump. This method can also ensure that multiple beams in a single cell are scheduled in the same beam group, so that the time when the uplink data (or uplink message or uplink signal, etc.) sent by the terminal device located in the single cell reaches the network device can be aligned.

[0112] Optionally, in order to ensure that the uplink data of multiple beams in a single cell can be aligned, the network device can constrain multiple beams at the same time to be able to only be scheduled in the same beam group in parallel, and time division multiplexing (TDM) between different beam groups, which is helpful to ensure that the time when the uplink data sent by the terminal device in the single cell reaches the network device is aligned, for example, at time 1, multiple beams are only scheduled in beam area 1, and at time 2, multiple beams are only scheduled in beam area 2.

[0113] The second mode: taking the first beam group as an example, the difference between the maximum round trip time corresponding to the first beam group and the third value is less than or equal to the first value, and / or, the difference between the maximum round trip time corresponding to the first beam group and the third value is less than or equal to the second value. Wherein, the third value is equal to the sum of the minimum round trip time corresponding to the first beam group and the length of the cyclic prefix carried in the third message.

[0114] For example, the preset beam grouping rule in the second mode can satisfy the following form:

[0115] (1) max(RTT) - third value ≤ RAR' + Msg3_CP, and / or, (2) max(RTT) - third value ≤ randomaccess preamble_CP, third value ≤ min(RTT) + Msg3_CP;

[0116] Optionally, different beam groups in the second mode pre-compensate different time delay compensation values, and at least one beam in a same beam group pre-compensates a same time delay compensation value. For example, the time delay compensation value of each beam group is ≤ min(RTT) + Msg3 CP. Optionally, the time delay compensation value of each beam group can be greater than 0. In this way, for the same beam group, since the at least one beam included in the beam group pre-compensates the same time delay compensation value, when a certain terminal device switches between the at least one beam included in the beam group, time offset jump will not occur, and only time offset jump between different beam groups will occur, thereby greatly reducing the frequency of time offset jump, and ensuring that multiple beams of a single cell are scheduled in a same beam group, so that the time at which uplink data sent by a terminal device located in the single cell reaches the network device can be aligned.

[0117] Of course, the network device can also ensure that the time offset of a certain beam group is within the adjustable range after pre-compensation of the same time delay compensation value, and even the residual time offset is within the length of the CP included in Msg3, thereby ensuring that the network device can correctly receive Msg3, by grouping the multiple beams generated by the satellite according to formula (1) in the second mode. The network device can also ensure that the network device can correctly receive the random access preamble from the terminal device, thereby ensuring the correct performance of the subsequent process, by grouping the multiple beams generated by the satellite according to formula (2) in the second mode.

[0118] For example, in the above-mentioned first mode, when the preset beam grouping rule only needs to satisfy formula (1) in the first mode, the network device can first obtain the round trip time (i.e., multiple round trip times) between multiple position points in the area covered by the multiple beams generated by the satellite and the position point of the network device from other devices, or the network device can first calculate the round trip time (i.e., multiple round trip times) between multiple position points in the area covered by the multiple beams generated by the satellite and the position point of the network device. Then, the network device can determine the maximum round trip time from the multiple round trip times, and can determine the first value according to the maximum time offset that can be adjusted by the TAC in the second message and the length of the CP carried in Msg3. Then, the network device can calculate the first difference between the maximum round trip time and the first value, and can select a round trip time greater than or equal to the first difference from the other round trip times except the maximum round trip time in the multiple round trip times, i.e., at least one round trip time. Finally, the network device can form a beam group from the beam corresponding to the position point of the maximum round trip time and the beam group corresponding to the position point of the selected at least one round trip time. Optionally, the network device can determine the minimum round trip time from the at least one round trip time corresponding to the beam group, and can take the minimum round trip time as the time delay compensation value of the beam group.

[0119] After dividing the beam groups as described above, if there is still one beam among the multiple beams generated by the satellite that has not been grouped, the network device can group that beam into a separate beam group. Optionally, the network device can determine the minimum round-trip time from at least one round-trip time corresponding to that beam, and can use that minimum round-trip time as the delay compensation value for that beam group.

[0120] If at least two of the multiple beams generated by the satellite remain ungrouped, the network device can determine the maximum round-trip time (RTT) from the multiple RTTs corresponding to these at least two beams, and calculate a second difference between the maximum RTT and a first value. Then, the network device can select a RTT greater than or equal to the second difference from the other RTTs corresponding to the at least two beams, thus selecting at least one RTT. The network device can then group the beam to which the location point corresponding to the maximum RTT belongs, along with the beam to which the location point corresponding to the selected at least one RTT belongs, into another beam group, until all the multiple beams generated by the satellite are grouped. Optionally, the network device can determine the minimum RTT from the at least one RTT corresponding to this other beam group and use this minimum RTT as the delay compensation value for this other beam group.

[0121] For example, the result of the network device grouping multiple beams generated by the satellite according to the above grouping method can be found in [reference needed]. Figure 4 In that Figure 4 In the process, the multiple beams generated by the satellite are divided into three beam groups, each beam group corresponding to a beam region, namely beam region 1, beam region 2, and beam region 3. Each beam region contains at least one beam.

[0122] Optionally, when the preset beam grouping rule only needs to satisfy the formula (2) in the manner one, the network device can first acquire, from the other devices, the round trip delays (i.e., multiple round trip delays) between multiple position points in the areas covered by the multiple beams generated by the satellite and the position point where the network device is located, or the network device can first calculate the round trip delays (i.e., multiple round trip delays) between multiple position points in the areas covered by the multiple beams generated by the satellite and the position point where the network device is located. Then, the network device can determine the maximum round trip delay from the multiple round trip delays, and can calculate a third difference value between the maximum round trip delay and the length of the CP contained in the random access preamble. Then, the network device can select, from the round trip delays other than the maximum round trip delay among the multiple round trip delays, a round trip delay greater than or equal to the third difference value, i.e., at least one round trip delay. Finally, the network device can form a beam group by the beam to which the position point corresponding to the maximum round trip delay belongs and the beam to which the position point corresponding to the selected at least one round trip delay belongs. Optionally, the network device can determine the minimum round trip delay from the at least one round trip delay corresponding to the beam group, and can take the minimum round trip delay as the time delay compensation value of the beam group.

[0123] After the network device divides the above beam group, if there is still one beam among the multiple beams generated by the satellite that has not been grouped, the network device can form a beam group by the beam alone. Optionally, the network device can determine the minimum round trip delay from the at least one round trip delay corresponding to the beam, and can take the minimum round trip delay as the time delay compensation value of the beam group.

[0124] If there are still at least two beams among the multiple beams generated by the satellite that have not been grouped, the network device can determine the maximum round trip delay from the multiple round trip delays corresponding to the at least two beams, and can calculate a fourth difference value between the maximum round trip delay and the length of the CP contained in the random access preamble. Then, the network device can select, from the multiple round trip delays other than the maximum round trip delay corresponding to the at least two beams, a round trip delay greater than or equal to the fourth difference value, i.e., at least one round trip delay. Then, the network device can form another beam group by the beam to which the position point corresponding to the maximum round trip delay belongs and the beam to which the position point corresponding to the selected at least one round trip delay belongs, until all the multiple beams generated by the satellite are grouped. Optionally, the network device can determine the minimum round trip delay from the at least one round trip delay corresponding to the another beam group, and can take the minimum round trip delay as the time delay compensation value of the another beam group.

[0125] Optionally, when the preset beam grouping rule needs to satisfy formula (1) and formula (2) in mode one at the same time, the network device can first obtain, from the other device, the round trip delays (i.e., multiple round trip delays) between multiple position points in the areas covered by the multiple beams generated by the satellite and the position point where the network device is located, or the network device can first calculate the round trip delays (i.e., multiple round trip delays) between multiple position points in the areas covered by the multiple beams generated by the satellite and the position point where the network device is located. Then, the network device can determine the maximum round trip delay from the multiple round trip delays, and can determine the first value according to the maximum time offset that can be adjusted by the TAC in the second message and the length of the CP carried in the Msg3. Then, the network device can calculate the first difference value between the maximum round trip delay and the first value, and can calculate the third difference value between the maximum round trip delay and the length of the CP contained in the random access preamble. Finally, the network device can select, from the other round trip delays in the multiple round trip delays except the maximum round trip delay, the round trip delays that are greater than or equal to the first difference value and greater than or equal to the third difference value, that is, at least one round trip delay. Finally, the network device can form a beam group by the beam to which the position point corresponding to the maximum round trip delay belongs and the beams to which the position points corresponding to the selected at least one round trip delay belong. Optionally, the network device can determine the minimum round trip delay from the at least one round trip delay corresponding to the beam group, and can take the minimum round trip delay as the time delay compensation value of the beam group.

[0126] After the network device divides the above beam groups, if there is still one beam in the multiple beams generated by the satellite that has not been grouped, the network device can form a beam group by the beam alone. Optionally, the network device can determine the minimum round trip delay from the at least one round trip delay corresponding to the beam, and can take the minimum round trip delay as the time delay compensation value of the beam group.

[0127] If there are still at least two beams of the plurality of beams generated by the satellite that are not grouped, the network device can determine a maximum round-trip delay from the plurality of round-trip delays corresponding to the at least two beams, and can calculate a second difference between the maximum round-trip delay and the first value, and a fourth difference between the maximum round-trip delay and the length of the CP included in the random access preamble. Then, the network device can select, from the round-trip delays other than the maximum round-trip delay in the plurality of round-trip delays corresponding to the at least two beams, a round-trip delay that is greater than or equal to the second difference and greater than or equal to the fourth difference, that is, at least one round-trip delay. Then, the network device can group the beam to which the position point corresponding to the maximum round-trip delay belongs and the beam to which the position point corresponding to the at least one round-trip delay selected is grouped into another beam group, until all the plurality of beams generated by the satellite are grouped. Optionally, the network device can determine a minimum round-trip delay from the at least one round-trip delay corresponding to the another beam group, and can take the minimum round-trip delay as the time delay compensation value of the another beam group.

[0128] It should be understood that the above is only an exemplary introduction to the possible way of grouping the plurality of beams generated by the satellite by the network device, and the network device can also group the plurality of beams generated by the satellite in other ways, which will not be listed one by one in this application.

[0129] Exemplarily, taking the first beam area as an example, the terminal device located in the first beam area can send a first message to the network device when needing to initiate a random access process, and the first message can be used to indicate that the terminal device located in the first beam area requests to access the network device.

[0130] For example, when a certain terminal device located in the first beam area is in the initial stage of random access, such as the terminal device has not formally accessed the network device or the terminal device is in the RRC non-connected state (such as the RRC idle state or the RRC inactive state), etc., the terminal device can receive the synchronization signal block broadcasted by the network device in a frequency sweeping manner, thereby obtaining the time-frequency offset information of the synchronization signal block, and can obtain the search space of the system information block (SIB) 1. The terminal device can obtain the SIB1 from the network device in the search space of the SIB1, and the SIB1 carries the PRACH resource (such as the PRACH time domain resource or the PRACH frequency domain resource, etc.). Then, the terminal device can initiate a random access process by using the PRACH resource, such as the terminal device sends a first message (i.e. Msg1) to the network device by using the PRACH resource, that is, sends a random access request to the network device.

[0131] Optionally, the network device can also broadcast the location information of the network device or other information used to determine the location information of the network device through the SIB1. The following is exemplarily illustrated by the following possible examples.

[0132] Example one: in a satellite system, the SIB1 broadcast by the network device (such as a satellite or a satellite ground station) can contain ephemeris used to calculate and predict the position of the satellite. After obtaining the SIB1 broadcast by the network device, the terminal device can calculate the position information of the satellite based on the ephemeris in the SIB1.

[0133] Example two: the SIB1 broadcast by the network device can contain real-time location information of the network device. In this way, the terminal device can obtain the location information of the network device contained in the SIB1.

[0134] Optionally, in wireless communication, uplink synchronization between the terminal device and the network device is realized through a random access (RA) process. Exemplarily, the terminal device can initiate the random access process when it is in the following scenarios: (1) initial access from the radio resource control idle (RRC_IDLE) state, i.e. RRC connection establishment; (2) radio resource control connection reestablishment; (3) cell handover; (4) the synchronization state of the uplink of the terminal device is uplink unsynchronized; (5) request for other SI; (6) beam recovery request; or (7) switching from the radio resource control inactive state, etc.

[0135] Optionally, the random access process is divided into a contention-based random access process and a non-contention-based random access process. In the non-contention-based random access process, the network device can allocate a random access preamble to the terminal device and can send an indication message carrying the random access preamble to the terminal device. After receiving the indication message, the terminal device initiates the non-contention-based random access process. In the contention-based random access process, the terminal can initiate the contention-based random access process according to its own needs.

[0136] Optionally, in one example, the terminal device can send a first message to the network device after receiving the first indication information of the network device. The first indication information is used to indicate that the terminal device initiates the random access process, and the first message is used to indicate that the terminal device requests to access the network device in the random access process. Optionally, the first indication message carries the random access preamble allocated by the network device to the terminal device, and the first message carries the random access preamble.

[0137] In another example, the terminal device can send the first message to the network device at initial access. In this case, the first message carries a random access preamble. For example, the terminal device can trigger initial access when it is powered on or when it is turned off from the flight mode.

[0138] In yet another example, the terminal device can send the first message to the network device at cell switching. In this case, the first message carries a random access preamble.

[0139] In some other examples, the terminal device can also send the first message to the network device at uplink synchronization or RRC connection reestablishment, etc. In this case, the first message carries a random access preamble.

[0140] It should be noted that the above is only an example of triggering the terminal device to send the first message to the network device, and does not constitute a limitation on the embodiments of the present application. In the embodiments of the present application, the terminal device can also be triggered to send the first message to the network device in other ways.

[0141] Step 302: When the network device receives the first message from the terminal device in the first beam area, the first parameter value required by the terminal device to adjust the TA is determined according to the round-trip delay between the terminal device and the network device and the delay compensation value of the first beam area.

[0142] Optionally, the delay compensation value of the first beam area can be the delay compensation made by the network device for the message (or signal, etc.) from the terminal device in the first beam area, i.e., the delay compensation value of the first beam area can be the delay compensation made by the network device when receiving the message (or signal, etc.) from the terminal device in the first beam area in order to compensate for the timing difference caused by the round-trip delay between the terminal device and the network device. For example, the delay compensation can be understood as a backward time delay operation on the receiving window when the network device receives the message (or signal, etc.) from the terminal device in the first beam area, and the size of the backward time delay of the receiving window is the delay compensation value of the first beam area.

[0143] Exemplarily, taking a certain terminal device located in the first beam area as an example, the implementation process of the network device receiving the first message from the terminal device is introduced. Optionally, after the network device determines the time delay compensation value of the at least one beam area, for a certain terminal device located in the first beam area, the network device can determine the first receiving time of the first message according to the random access channel occasion corresponding to the terminal device and the time delay compensation value of the first beam area. When the first receiving time of the first message arrives, the network device can receive the first message. That is to say, the network device can receive the first message from the terminal device by delaying the time delay compensation value of the first beam area on the basis of the random access channel occasion. Exemplarily, assuming that the random access channel occasion corresponding to the terminal device is t0 and the time delay compensation value of the first beam area is t1, the network device can calculate the first receiving time of the first message as (t0+t1).

[0144] Optionally, the time delay compensation value of the first beam area can be used to assist the network device in determining the first parameter value required by the terminal device located in the first beam area to adjust the TA.

[0145] Exemplarily, when the network device receives the first message from a terminal device located in a certain beam area (such as the first beam area), the network device can determine the first parameter value required by the terminal device to adjust the TA according to the time delay compensation value of the first beam area (i.e., the time delay compensation value of the first beam group) and the round-trip time delay between the terminal device and the network device. Optionally, in one example, in the implementation process of the terminal device accessing the network device, the round-trip time delay between the terminal device and the network device can be determined by the network device according to the random access preamble from the terminal device. In another example, in the implementation process of the terminal device re-accessing the network device, the round-trip time delay between the terminal device and the network device can be determined by the network device according to the prior time offset information, wherein the terminal device is located in the coverage area of the current satellite.

[0146] For example, assuming that the time delay compensation value of the first beam area is t1 and the round-trip time delay between the terminal device and the network device is t2, the network device can calculate the first parameter value required by the terminal device to adjust the TA as (t2-t1).

[0147] Step 303: The network device sends a second message to the terminal device.

[0148] Optionally, the second message can be used to indicate the request response of the network device to the terminal device in the random access process, and the first parameter value can be carried in the second message.

[0149] For example, taking a base station as an example, when the base station receives a first message from a terminal device located in a first beam area, or when the base station detects a random access preamble carried in the first message, the base station can send a RAR to the terminal device, which can also be referred to as a second message (i.e., Msg2).

[0150] Optionally, the RAR can include, but is not limited to, a sequence number of the random access preamble, a first parameter value, uplink resource allocation information (such as information of uplink resources allocated for a third message (i.e., Msg3), and the like), or a cell radio network temporary identifier, and the like. The uplink resources allocated for the third message can be physical uplink shared channel (PUSCH) resources. Illustratively, the uplink resource allocation information can include resource information for transmitting or scheduling the Msg3. Illustratively, the first parameter value can be transmitted to the terminal device in the form of a TAC (i.e., a range of indicated TA adjustment values, or also referred to as an indicated TA value or an indicated range of TA).

[0151] In addition, optionally, the RAR can also include an uplink scheduling UL grant, which can also be referred to as a RAR grant indication field. Illustratively, the UL grant can include, but is not limited to, a frequency hopping identifier, PUSCH frequency domain resource allocation, or PUSCH time domain resource indication, and the like.

[0152] Optionally, after the network device sends the second message to the terminal device, the network device can receive an uplink message from the terminal device. Illustratively, the implementation process of the network device receiving a first uplink message from a terminal device located in the first beam area is introduced. Optionally, after the network device sends the second message to the terminal device, for a terminal device located in the first beam area, the network device can determine a second reception time of the first uplink message according to a transmission time of the first uplink message corresponding to the terminal device and a time delay compensation value of the first beam area. When the second reception time of the first uplink message arrives, the network device can receive the first uplink message. The first uplink message is used to indicate an uplink message transmitted by the terminal device after the second message. That is, the network device can receive the first uplink message from the terminal device by moving back or delaying the transmission time of the first uplink message by the time delay compensation value of the first beam area. Illustratively, assuming that the transmission time of the first uplink message corresponding to the terminal device is t3, and the time delay compensation value of the first beam area is t1, the network device can calculate the second reception time of the first uplink message as (t3+t1).

[0153] In addition, optionally, after the terminal devices in different beam areas successfully access the network device in the random access stage, in order to align the time when the uplink data sent by the terminal devices in different beam areas reaches the network device in the data transmission stage, the network device can adjust the TA required for the terminal devices in some beam areas to send uplink messages, so that the time when the uplink data sent by the terminal devices in different beam areas reaches the network device in the data transmission stage is aligned, thereby improving the flexibility of beam scheduling in the data transmission stage, and helping to realize that multiple beams of the same cell can be simultaneously scheduled among different beams with aligned uplink data arrival time.

[0154] For example, taking a certain terminal device located in the first beam area as an example, after the terminal device successfully accesses the network device, the network device can send a fourth message to the terminal device to adjust the TA required for the terminal device to send uplink messages. Optionally, the fourth message is used to instruct the terminal device to adjust the TA, and the fourth message carries a second parameter value required for the terminal device to adjust the TA, and the second parameter value is determined by the network device according to the difference between the uplink message receiving time corresponding to the first beam area (i.e., the receiving time of the network device receiving the uplink message from the terminal device in the first beam area) and the uplink message receiving time corresponding to the second beam area (i.e., the receiving time of the network device receiving the uplink message from the terminal device in the second beam area), and the second beam area is the coverage area of at least one second beam included in the second beam group. Optionally, the second beam area can be used as a reference area or a reference area for aligning the time when the uplink data sent by the terminal devices in different beam areas reaches the network device.

[0155] For example, taking a certain terminal device located in the first beam area as an example, after the terminal device successfully accesses the network device, the network device can send a fourth message to the terminal device to adjust the TA required for the terminal device to send uplink messages. Optionally, the fourth message is used to instruct the terminal device to adjust the TA, and the fourth message carries a second parameter value required for the terminal device to adjust the TA, and the second parameter value is determined by the network device according to the difference between the uplink message receiving time corresponding to the first beam area (i.e., the receiving time of the network device receiving the uplink message from the terminal device in the first beam area) and the uplink message receiving time corresponding to the second beam area (i.e., the receiving time of the network device receiving the uplink message from the terminal device in the second beam area), and the second beam area is the coverage area of at least one second beam included in the second beam group. Optionally, the second beam area can be used as a reference area or a reference area for aligning the time when the uplink data sent by the terminal devices in different beam areas reaches the network device.

[0156] When a terminal device (such as terminal A) located in the beam area 2 successfully accesses the base station, the base station can first calculate the second parameter value required for the terminal device located in the beam area 2 to adjust the TA as (t5-t4) according to the uplink message receiving time t4 corresponding to the beam area 1 and the uplink message receiving time t5 corresponding to the beam area 2. Then, the base station can send an instruction for adjusting the TA to the terminal A located in the beam area 2 through a medium access control (MAC) control element (CE) or a download control information (DCI), etc. The instruction can carry the second parameter value (t5-t4). After receiving the instruction, the terminal A can adjust the TA of the terminal A according to the second parameter value (t5-t4).

[0157] Optionally, since the range of the TA adjustment value that can be indicated in the instruction is limited, the base station may need to send an instruction to the terminal A for adjusting the TA, and the instruction for adjusting the TA carries the second parameter value (t5-t4), or the base station may need to send multiple instructions for adjusting the TA to the terminal A, and each instruction for adjusting the TA carries a part of the value of the second parameter value (t5-t4). In this way, the base station can make the time when the uplink data sent by the terminal device located in the beam area 1 reaches the base station and the time when the uplink data sent by the terminal device located in the beam area 2 reaches the base station align by adjusting the TA of the terminal device located in the beam area 2 at least once, which helps to improve the flexibility of beam scheduling in the data transmission stage, and can realize that multiple beams of the same cell can be simultaneously scheduled among different beam areas with aligned uplink data arrival time.

[0158] Step 304: The terminal device adjusts the TA required for the terminal device to send the first uplink message according to the first parameter value carried in the second message.

[0159] Optionally, when the terminal device located in the first beam area receives the second message from the network device, the terminal device can obtain the first parameter value carried in the second message, and can adjust the TA required for the terminal device to send the first uplink message according to the first parameter value. After adjusting the TA, the terminal device can send the first uplink message (such as Msg3) to the network device according to the adjusted TA.

[0160] In addition, exemplarily, taking the first beam area as an example, after the terminal device located in the first beam area receives the second message from the network device, in order to realize that the uplink data sent by the terminal devices in different beam areas can reach the network device at the same time, the terminal device located in the first beam area can receive a fourth message from the network device. The fourth message is used to instruct the terminal device to adjust the TA, and the fourth message carries a second parameter value required for the terminal device to adjust the TA. Then, the terminal device can adjust the TA required for the terminal device to send the uplink message according to the second parameter value. In this way, the network device can adjust the TA required for the terminal devices in some beam areas to send the uplink message, so as to help realize that the uplink data sent by the terminal devices in different beam areas can reach the network device at the same time in the data transmission stage, and the flexibility of beam scheduling in the data transmission stage can be improved.

[0161] Exemplarily, taking a certain terminal device (such as terminal A) located in the first beam area as an example, and taking the network device as a base station, when the terminal A successfully accesses the base station, the terminal A can receive a fourth message from the base station. The fourth message is used to instruct the terminal A to adjust the TA, and the fourth message carries a second parameter value required for the terminal A to adjust the TA. Then, the terminal A can adjust the TA required for the terminal A to send the uplink message according to the second parameter value. For example, assuming that the current TA of the terminal A is TA1, the terminal A can adjust the TA1 according to the second parameter value, and the adjusted TA1 is used for the terminal A to send other uplink messages (or other uplink data or other uplink signals, etc.).

[0162] As can be seen from the above steps 301 to 304, the network device can ensure that the terminal device does not appear time offset jump when performing beam switching in the beam area corresponding to the same beam group by allocating the same time delay compensation value to the multiple beams belonging to the same beam group, thereby effectively reducing the frequency of time offset jump. In addition, the method can also ensure that the multiple beams in a single cell (that is, the same cell) are scheduled in the same beam group, so that the uplink data (or uplink message or uplink signal, etc.) sent by the terminal device located in the single cell can reach the network device at the same time.

[0163] Exemplarily, based on the technical solutions provided in the above steps 301 to 304, the following takes the network device as a base station to introduce the implementation process of the terminal device located in a certain beam area randomly accessing the network device after the network device allocates the time delay compensation value to the beam area.

[0164] Referring to Figure 5 , Figure 5An exemplary flowchart of another communication method provided by the embodiments of the present application is shown. The method is applicable to Figure 1 or Figure 2 the satellite system shown. The method flow is achieved by data interaction between the terminal device and the base station.

[0165] Step 501: The base station broadcasts a synchronization signal block. The terminal device located in the coverage range of the base station receives the synchronization signal block from the base station.

[0166] Optionally, at this time, the terminal device is in an initial access stage, and the RRC connection state of the terminal device is an RRC non-connected state (RRC idle state or RRC non-active state). The terminal device can receive the synchronization signal block in a frequency sweeping manner, so as to obtain the time-frequency offset information of the synchronization signal block.

[0167] Step 502: The terminal device obtains a search space of a system information block according to the time-frequency offset information of the synchronization signal block.

[0168] Step 503: The terminal device obtains a system information block from the base station in the search space of the system information block. The system information block is broadcast by the base station.

[0169] Optionally, the base station can periodically broadcast a system information block (such as SIB1), and the terminal device can obtain the system information block broadcast by the base station in the search space of the system information block.

[0170] Step 504: The terminal device sends a random access preamble to the base station using the physical random access channel resource carried in the system information block.

[0171] Step 505: When the reception time of the random access preamble arrives, the base station receives the random access preamble.

[0172] Optionally, the base station can determine the reception time of the random access preamble according to the sending time of the random access preamble sent by the terminal device and the time delay compensation value of the beam area where the terminal device is located. When the reception time of the random access preamble arrives, the base station can receive the random access preamble.

[0173] Step 506: The base station sends a random access response to the terminal device.

[0174] Optionally, the random access response can carry at least one of the sequence number of the random access preamble, the first parameter value, the uplink resource allocation information, or the cell radio network temporary identifier.

[0175] Optionally, when the base station receives the random access preamble from the terminal device, the base station can send a random access response to the terminal device.

[0176] Step 507: The terminal device sends an uplink message to the base station according to the random access response.

[0177] Step 508: When the receiving time of the uplink message arrives, the base station receives the uplink message.

[0178] Optionally, the base station can determine the receiving time of the uplink message according to the sending time of the terminal device sending the uplink message and the time delay compensation value of the beam area where the terminal device is located. When the receiving time of the uplink message arrives, the base station can receive the uplink message. Exemplarily, the time interval between the time when the base station sends downlink data and the time when the base station receives uplink data can refer to Figure 6 , by Figure 6 It can be seen that the interval between the sending time of the base station sending downlink data (such as random access response) and the receiving time of the base station receiving uplink data (such as uplink message) is the time delay compensation value of the beam area where the terminal device is located (i.e. t 01 -t 00 ).

[0179] It can be seen from the above steps 501 to 508 that after the base station allocates the time delay compensation value for the beam area where the terminal device is located, the base station can move back or delay the time delay compensation value on the basis of the sending time of the terminal device sending the random access preamble to receive the random access preamble from the terminal device, and the base station can also move back or delay the time delay compensation value on the basis of the sending time of the terminal device sending the uplink message to receive the uplink message from the terminal device, so as to ensure that the uplink data (such as random access preamble or uplink message) sent by the terminal device located in the beam area can arrive at the base station at the same time.

[0180] It should be noted that in the description of the present application, "at least one" means one or more, and "multiple" means two or more. The association relationship between the associated objects is described, which means that there can be three relationships, for example, A and / or B, which can represent the cases of A alone, A and B together, and B alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. In addition, unless otherwise specified, the ordinal numbers "first", "second", "third" and the like mentioned in the embodiments of the present application are used to distinguish a plurality of objects, and are not used to limit the order, time sequence, priority or importance of the plurality of objects. In addition, the terms "include", "contain", "have" and their variants appearing in the present application mean "include but not limited to", unless otherwise specifically emphasized.

[0181] In addition, it should be noted that each step involved in the above embodiments can be performed by the corresponding device or by the components such as chips, processors or chip systems within the device, and the embodiments of the present application do not constitute a limitation. The above embodiments are only described by taking the execution by the corresponding device as an example.

[0182] It should be noted that in the above embodiments, some steps can be selected for implementation, and the order of the steps in the diagram can be adjusted for implementation, and the present application does not limit this. It should be understood that the implementation of some steps in the diagram, the adjustment of the order of the steps or the combination of the above for specific implementation all fall within the protection scope of the present application.

[0183] It can be understood that in order to realize the functions in the above embodiments, each device involved in the above embodiments includes corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should easily realize that the units and method steps of each example described in combination with the embodiments disclosed in the present application can be realized in the form of hardware or hardware and computer software. Whether a certain function is executed in hardware or computer software driven hardware depends on the specific application scenario and design constraints of the technical solution.

[0184] It should be noted that the "step" in the embodiments of the present application is only a demonstration, which is a kind of expression method for better understanding the embodiments, and does not constitute a substantial limitation on the execution of the scheme of the present application. For example, the "step" can also be understood as "feature". In addition, the step does not constitute any limitation on the execution order of the scheme of the present application. Any step order change, step merging or step splitting operation made on this basis without affecting the overall scheme implementation, the new technical scheme formed is also within the scope disclosed by the present application.

[0185] Based on the same idea, the embodiments of the present application also provide a possible communication device, which is suitable for Figure 1 or Figure 2 the satellite system as illustrated. Optionally, the communication device can be a communication equipment (such as a network equipment or a terminal equipment), or can also be a chip or the like arranged in the communication equipment (such as a network equipment or a terminal equipment). Optionally, in one example, when the communication device is a network equipment, the communication device is used to implement the technical scheme related to the network equipment in the above embodiments, or the module (such as a chip) of the communication device is used to implement the technical scheme related to the network equipment in the above embodiments, so that the beneficial effects possessed by the network equipment in the above embodiments can also be achieved. For example, the communication device can be the satellite ground station (or satellite, etc.) as illustrated in Figure 1 or Figure 2 In another example, when the communication device is a terminal equipment, the communication device is used to implement the technical scheme related to the terminal equipment in the above embodiments, or the module (such as a chip) of the communication device is used to implement the technical scheme related to the terminal equipment in the above embodiments, so that the beneficial effects possessed by the terminal equipment in the above embodiments can also be achieved. For example, the communication device can be the terminal equipment as illustrated in Figure 1 or Figure 2

[0186] Referring to Figure 7 , the communication device 700 includes a communication module 701 and a processing module 702. The communication device 700 is used to implement the functions of the network equipment or the terminal equipment in the method embodiments as illustrated in Figure 3

[0187] When the communication device 700 is used to implement the method embodiments as illustrated in Figure 3 ​​When the network device in the method embodiment is used for implementing the function: the processing module 702 is used for, when receiving a first message from a terminal device in a first beam area, determining a first parameter value required by the terminal device to adjust TA according to a round-trip delay between the terminal device and the network device and a time delay compensation value of the first beam area. The first beam area is a coverage area of at least one first beam included in a first beam group, and the first message is used for indicating that the terminal device requests to access the network device in a random access process. The communication module 701 is used for sending a second message to the terminal device. The first parameter value is carried in the second message, and the second message is used for indicating a response of the network device to the request of the terminal device in the random access process.

[0188] When the communication apparatus 700 is used for implementing the function of the network device, the communication module 701 is used for sending a first message to a terminal device. The first message is used for indicating that the network device requests to access the terminal device, and the terminal device is located in a first beam area. The communication module 701 is also used for receiving a second message from the terminal device. The first parameter value is carried in the second message, and the second message is used for indicating a response of the terminal device to the request of the network device in a random access process. The processing module 702 is used for adjusting TA required by the terminal device to send a first uplink message according to the first parameter value. The first parameter value is determined by the network device according to a round-trip delay between the terminal device and the network device and a time delay compensation value of the first beam area, the first beam area is a coverage area of at least one first beam included in a first beam group, and the first uplink message is used for indicating an uplink message sent by the terminal device after the second message. Figure 3

[0189] For more detailed description of the communication module 701 and the processing module 702, refer to the related description of the network device or the terminal device in the above method embodiment, which will not be repeated here.

[0190] It should be understood that the communication module 701 in the embodiment of the application can be realized by a transceiver or a transceiver related circuit component, and the processing module 702 can be realized by a processor or a processor related circuit component.

[0191] It should be noted that the division of the module in the embodiment of the application is illustrative, and is only a logical function division. In actual implementation, another division mode can be used. In addition, each functional unit in each embodiment of the application can be integrated in one processing unit, or can be physically separated, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0192] ​The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part of the prior art that contributes to the present application or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, etc.) or a processor to perform all or part of the steps of the embodiments of the method of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0193] Based on the same idea, the present application also provides a possible network device suitable for Figure 1 or Figure 2 the satellite system shown. The network device is used to implement the technical solutions related to the network device in the above embodiments, and thus can also achieve the beneficial effects possessed by the network device in the above method embodiments. Referring to Figure 8 , the network device 800 includes a first transceiver 801, a first processor 802. Optionally, the network device 800 further includes a first memory 803. Among them, the first transceiver 801, the first processor 802 and the first memory 803 are connected with each other. When the network device 800 is used to implement the technical solutions related to the network device in the above embodiments, the first transceiver 801 can be used to implement the functions of the communication module 701, and the first processor 802 is used to implement the functions of the processing module 702.

[0194] Optionally, the first transceiver 801, the first processor 802 and the first memory 803 are connected with each other through a bus 804. The bus 804 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of expression, Figure 8 only one thick line is used in the figure, but it does not mean that there is only one bus or only one type of bus.

[0195] The first transceiver 801 is used to receive and send data, for example, when the network device is as Figure 1The first transceiver 801 is configured to implement communication with Figure 1 the CN, or also can implement communication with Figure 1 the satellite.

[0196] The functions of the first processor 802 can refer to the descriptions of the corresponding functions of the network device in the above embodiments, and will not be described here. The first processor 802 can be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP, etc. The first processor 802 can further include a hardware chip. The hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. The first processor 802 can implement the above functions by hardware, and of course can also execute corresponding software by hardware.

[0197] The first memory 803 is configured to store program instructions and the like. Specifically, the program instructions can include program codes including computer operation instructions. The first memory 803 can include a random access memory (RAM) and can also include a non-volatile memory such as at least one disk memory. The first processor 802 executes the program instructions stored in the first memory 803 to implement the above functions, thereby implementing the method steps required to be executed by the network device in the above embodiments.

[0198] Based on the same idea, the present application also provides a possible terminal device, which is suitable for Figure 1 or Figure 2 the satellite system. The terminal device is used to implement the technical solutions related to the terminal device in the above embodiments, and thus can also achieve the beneficial effects possessed by the terminal device in the above method embodiments. For details, please refer to Figure 9The terminal device 900 comprises a second transceiver 901, a second processor 902. Optionally, the terminal device 900 further comprises a second memory 903. The second transceiver 901, the second processor 902 and the second memory 903 are connected with each other. When the terminal device 900 is used to implement the technical solutions related to the terminal device in the above embodiments, the second transceiver 901 can be used to implement the functions of the communication module 701, and the second processor 902 is used to implement the functions of the processing module 702.

[0199] Optionally, the second transceiver 901, the second processor 902 and the second memory 903 are connected with each other through a bus 904. The bus 904 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, Figure 9 In the figure, only one thick line is used to represent the bus, but it does not mean that there is only one bus or only one type of bus.

[0200] The second transceiver 901 is used to receive and send data. For example, when the terminal device is the terminal device as shown in Figure 1 or Figure 2 , the second transceiver 901 realizes communication with the satellite as shown in Figure 1 or Figure 2 , or can also realize communication with other devices (such as service devices) other than the satellite system as shown in Figure 1 or Figure 2 .

[0201] The functions of the second processor 902 can refer to the descriptions of the corresponding functions of the terminal device in the above embodiments, and will not be repeated here. The second processor 902 can be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP, etc. The second processor 902 can further include a hardware chip. The hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. The second processor 902 can be implemented by hardware, and of course, the corresponding software can also be executed by hardware.

[0202] The second memory 903 is configured to store program instructions and the like. Specifically, the program instructions can include program codes including computer operation instructions. The second memory 903 can include a random access memory (RAM) and can also include a non-volatile memory such as at least one disk memory. The second processor 902 executes the program instructions stored in the second memory 903 to implement the above functions, thereby implementing the method steps required to be executed by the terminal device in the above embodiments.

[0203] Based on the same idea, the embodiments of the present application also provide a communication system, which includes a network device and a terminal device. The network device can be used to implement the technical solutions related to the network device in the above embodiments, and the terminal device can be used to implement the technical solutions related to the terminal device in the above embodiments.

[0204] Based on the same idea, the embodiments of the present application also provide a computer program product, which includes a computer program or instructions, and when the computer program or instructions run on a computer, the computer executes the method provided by the above embodiments.

[0205] Based on the same concept, embodiments of this application also provide a computer-readable storage medium storing a computer program or instructions, which, when executed by a computer, causes the computer to perform the methods provided in the above embodiments.

[0206] The storage medium can be any available medium that a computer can access. For example, but not limited to, a computer-readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0207] Based on the same concept, this application also provides a chip coupled to a memory, which is used to read a computer program stored in the memory to implement the method provided in the above embodiments.

[0208] Based on the same concept, embodiments of this application also provide a chip system, which includes a processor for supporting a computer device in implementing the functions involved in the network device or terminal device in the above embodiments. In one possible design, the chip system further includes a memory for storing necessary programs and data of the computer device. This chip system may be composed of chips or may include chips and other discrete components.

[0209] The method provided by the embodiments of the present application can be implemented by software, hardware, firmware or any combination thereof, in whole or in part. When implemented by software, the method can be implemented in the form of a computer program product, in whole or in part. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the whole or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium, or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (such as floppy disk, hard disk, magnetic tape), optical media (such as high-density digital video disc (digital video disc, DVD)), or semiconductor media (such as solid state drive (solid state drive, SSD)) and the like.

[0210] The steps of the method described in the embodiments of the present application can be directly embedded in hardware, software unit executed by a processor, or a combination of the two. The software unit can be stored in RAM, ROM, EEPROM, register, hard disk, removable disk, CD-ROM or any other form of storage medium in the art. For example, the storage medium can be connected with the processor, so that the processor can read information from the storage medium, and can write information to the storage medium. Alternatively, the storage medium can also be integrated into the processor. The processor and the storage medium can be arranged in an ASIC.

[0211] The present application is described with reference to the flowcharts and / or block diagrams according to the method, device (system) and computer program product of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general purpose computer, a special purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a machine that implements the processes described in the flowcharts and / or block diagrams. Figure 1 one flow or multiple flows and / or blocksFigure 1 means for performing the function specified by the block or blocks.

[0212] These computer program instructions can also be loaded into computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable data processing devices to generate computer-implemented processes, thus the instructions executed on the computer or other programmable data processing devices provide processes for implementing the flows Figure 1 flows or a plurality of flows and / or blocks Figure 1 steps for performing the function specified by the block or blocks.

[0213] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A communication method, characterized in that, Applied to network devices, the method includes: When a first message is received from a terminal device within the first beam area, a first parameter value required for the terminal device to adjust its timing advance (TA) is determined based on the round-trip time (RTD) between the terminal device and the network device and the delay compensation value of the first beam area. The first beam area is the coverage area of ​​at least one first beam included in the first beam group. The first message is used to indicate that the terminal device requests access to the network device during random access. The at least one first beam included in the first beam group has the same delay compensation value. The first beam group is one of at least one beam group, and the at least one beam group is determined by grouping multiple beams corresponding to the network device according to a preset beam grouping rule. A second message is sent to the terminal device, the second message carrying the first parameter value, the second message being used to indicate the network device's response to the terminal device's request during random access.

2. The method as described in claim 1, characterized in that, The difference between the maximum round-trip time (RTT) and the minimum RTT corresponding to the first beam group is less than or equal to a first value, and / or the difference between the maximum RTT and the minimum RTT is less than or equal to a second value; or The difference between the maximum round-trip time and the third value is less than or equal to the first value, and / or the difference between the maximum round-trip time and the third value is less than or equal to the second value; Wherein, the first value is equal to the sum of the maximum adjustment length of the location region used to carry the first parameter value in the second message and the length of the cyclic prefix carried in the third message; the second value is the length of the cyclic prefix contained in the random access preamble carried in the first message; the third value is equal to the sum of the minimum round-trip time corresponding to the first beam group and the length of the cyclic prefix carried in the third message; the third message comes from the terminal device.

3. The method as described in claim 1 or 2, characterized in that, The delay compensation value of the first beam region is equal to the minimum round-trip time corresponding to the first beam group, or the delay compensation value of the first beam region is greater than 0 and less than or equal to the sum of the minimum round-trip time and the length of the cyclic prefix carried in the third message.

4. The method as described in claim 1 or 2, characterized in that, After sending the second message to the terminal device, the method further includes: Send a fourth message to the terminal device that has successfully accessed the network device within the first beam area; The fourth message is used to instruct the terminal device to adjust the TA. The fourth message carries a second parameter value required for the terminal device to adjust the TA. The second parameter value is determined based on the difference between the uplink message reception time corresponding to the first beam area and the uplink message reception time corresponding to the second beam area. The second beam area is the coverage area of ​​at least one second beam included in the second beam group.

5. The method as described in claim 1 or 2, characterized in that, The method further includes: The network device is divided into at least one beam group, and the at least one beam group includes the first beam group.

6. A communication method, characterized in that, Applied to a terminal device, the method includes: Send a first message to the network device, the first message being used to instruct the terminal device to request access to the network device, the terminal device being located within a first beam area; Receive a second message from the network device, the second message carrying a first parameter value, the second message being used to indicate the network device's response to the terminal device's request during random access; Based on the first parameter value, adjust the TA required for the terminal device to send the first uplink message; Wherein, the first parameter value is determined by the network device based on the round-trip time between the terminal device and the network device and the delay compensation value of the first beam area, the first beam area is the coverage area of ​​at least one first beam included in the first beam group, the first uplink message is used to indicate the uplink message sent by the terminal device after the second message; the at least one first beam included in the first beam group has the same delay compensation value, the first beam group is one of at least one beam group, and the at least one beam group is determined by grouping multiple beams corresponding to the network device according to a preset beam grouping rule.

7. The method as described in claim 6, characterized in that, The difference between the maximum round-trip time corresponding to the first beam group and the minimum round-trip time corresponding to the first beam group is less than or equal to a first value and less than or equal to a second value; or The difference between the maximum round-trip time corresponding to the first beam group and the third value is less than or equal to the first value and less than or equal to the second value; Wherein, the first value is equal to the sum of the maximum adjustment length of the location region used to carry the first parameter value in the second message and the length of the cyclic prefix carried in the third message; the second value is the length of the cyclic prefix contained in the random access preamble carried in the first message; the third value is equal to the sum of the minimum round-trip time corresponding to the first beam group and the length of the cyclic prefix carried in the third message; the third message comes from the terminal device.

8. The method as described in claim 6 or 7, characterized in that, After adjusting the TA required for the terminal device to send the first uplink message, the method further includes: When the terminal device successfully accesses the network device in the first beam area, it receives a fourth message from the network device. The fourth message is used to instruct the terminal device to adjust the TA. The fourth message carries a second parameter value required for the terminal device to adjust the TA. Adjust the TA of the terminal device according to the second parameter value; The second parameter value is determined based on the difference between the uplink message reception time corresponding to the first beam region and the uplink message reception time corresponding to the second beam region. The second beam region is the coverage area of ​​at least one second beam included in the second beam group.

9. A communication device, characterized in that, Includes a module for performing the method as described in any one of claims 1-8.

10. A network device, characterized in that, include: The first transceiver is used to receive and send data; The first memory is used to store computer program instructions and data; A first processor is configured to execute computer program instructions and data that invoke the first memory to cause the network device to perform the method as described in any one of claims 1-5.

11. A terminal device, characterized in that, include: The second transceiver is used to receive and send data; The second memory is used to store computer program instructions and data; A second processor is configured to execute computer program instructions and data that call the second memory to cause the terminal device to perform the method as described in any one of claims 6-8.

12. A communication system, characterized in that, This includes the network device as described in claim 10 and the terminal device as described in claim 11.

13. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed by a computer, cause the computer to perform the method as described in any one of claims 1-5 or any one of claims 6-8.

14. A computer program product, characterized in that, The computer program product includes a computer program or instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-5 or any one of claims 6-8.

15. A chip, characterized in that, The chip is coupled to a memory, and the chip reads a computer program stored in the memory to execute the method as described in any one of claims 1-5 or any one of claims 6-8.

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