Communication method, apparatus, terminal and network device

Abstract

The application provides a communication method, device, terminal and network equipment. The method is applied to a terminal, the terminal camps on a first network equipment, and the method comprises the following steps: a first preamble is sent to a second network equipment at a first sending time in advance of an estimated time advance of the second network equipment; a first message is sent to the second network equipment on a physical uplink shared channel (PUSCH) corresponding to the first preamble at a second sending time in advance of the estimated time advance, wherein the second sending time is separated from the first sending time by a first preset time. The application can quickly perform network equipment switching.

Description

TECHNICAL FIELD

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

[0002] The coverage range and orbital height of a network device both affect the quality of terminal services. Therefore, by means of different coverage ranges and latency characteristics of network devices, switching between network devices can be performed to ensure service continuity and reliability.

[0003] However, in the switching process between network devices, the terminal has problems such as long signal propagation distance, long processing time caused by signal demodulation and re-modulation, multiple nodes through which the signal needs to pass, and long terminal response time, resulting in large latency when the terminal switches between network devices. SUMMARY

[0004] The present application provides a communication method and device, a terminal and a network device, which can quickly switch between network devices.

[0005] In a first aspect, a communication method is provided, applied to a terminal, the terminal camping on a first network device, and the method comprising:

[0006] sending a first preamble to a second network device at a first sending time in advance of an estimated time advance of the second network device;

[0007] sending a first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble at a second sending time in advance of the estimated time advance, wherein the second sending time is separated from the first sending time by a first preset time.

[0008] In an implementation manner, the sending of the first preamble to the second network device comprises:

[0009] sending the first preamble to the second network device according to preamble configuration information, the preamble configuration information being used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and the first sending time of the first preamble being one of the at least one random access occasion.

[0010] In an implementation manner, the first preset time is predefined, or the first preset time is sent by the first network device.

[0011] In an implementation manner, the first message is one of the following: a radio resource control (RRC) connection setup complete message, an RRC reestablishment complete message, a handover complete message, an RRC reconfiguration complete message, or a redirection complete message.

[0012] In an implementation form, before the sending the first preamble to the second network device, the method further comprises:

[0013] sending a second message to the first network device;

[0014] receiving a third message from the first network device, the third message comprising the estimated time advance.

[0015] In an implementation form, the third message comprises radio configuration information configured by the second network device for the terminal.

[0016] In an implementation form, the third message further comprises frequency point information of the second network device.

[0017] In an implementation form, the third message further comprises a first temporary terminal identifier of the terminal, the first temporary terminal identifier being same as a temporary identifier allocated to the terminal by the first network device or being a temporary identifier reallocated to the terminal by the second network device.

[0018] In an implementation form, the preamble configuration information is obtained by one of the following ways:

[0019] receiving a system message broadcasted by the second network device, the system message comprising the preamble configuration information;

[0020] the third message further comprising a system message of the second network device, the system message comprising the preamble configuration information;

[0021] the third message further comprising the preamble configuration information.

[0022] In an implementation form, the third message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, ephemeris information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device or preamble sequence number information; wherein,

[0023] the preamble sequence number information is used to indicate the first preamble, and the first temporary terminal identifier is same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

[0024] In an implementation form, before the sending the first preamble to the second network device, the method further comprises:

[0025] sending a second message to the first network device;

[0026] receiving a third message from the first network device, the third message comprising ephemeris information of a second network device;

[0027] determining an estimated time advance of the second network device based on the ephemeris information of the second network device.

[0028] In an implementation form, the terminal obtains the preamble configuration information by one of the following manners:

[0029] receiving a system message broadcasted by the second network device, the system message comprising the preamble configuration information;

[0030] the third message further comprises a system message of the second network device, the system message comprising the preamble configuration information;

[0031] the third message further comprises the preamble configuration information.

[0032] In an implementation form, the third message further comprises at least one of the following parameters: wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, and a first temporary terminal identifier of the terminal, the first temporary terminal identifier being the same as a temporary identifier allocated to the terminal by the first network device or being a temporary identifier reallocated to the terminal by the second network device.

[0033] In an implementation form, the third message further comprises at least one of the following parameters: PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information used for indicating the first preamble.

[0034] In an implementation form, the second message comprises at least one of the following parameters: location information of the terminal, preset network device information, or service type information.

[0035] In an implementation form, the second message is one of the following: an RRC connection setup request message, an RRC reestablishment request message, a handover request message, or a redirection request message.

[0036] In an implementation form, the third message is one of the following: an RRC connection setup message, an RRC connection reestablishment message, a handover command message, or a redirection command message.

[0037] In an implementation form, after the first message is sent to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble, the method further comprises:

[0038] receiving a first timing advance from the second network device.

[0039] In an implementation form, the first network device has a different orbital height than the second network device.

[0040] In a second aspect, a communication method is provided, applied to a second network device, the method comprising:

[0041] receiving a first preamble from a terminal; the terminal camping on a first network device, the first preamble being transmitted at a first transmission time in advance of an estimated timing advance of the second network device;

[0042] determining timing offset information according to an actual receiving time window of the first preamble, the timing offset information being used to indicate a time offset between the actual receiving time window of the first preamble and a preset receiving time window of the first preamble;

[0043] receiving a first message on a physical uplink shared channel (PUSCH) corresponding to the first preamble according to the timing offset information; the first message being transmitted at a second transmission time in advance of the estimated timing advance, the second transmission time being separated from the first transmission time by a first preset time on the PUSCH.

[0044] In an implementation form, the first message is at least one of: an RRC connection setup complete message, an RRC reestablishment complete message, a handover complete message, an RRC reconfiguration complete message, or a redirection complete message.

[0045] In an implementation form, before the receiving the first preamble from the terminal, the method further comprises:

[0046] receiving a terminal access request message from the first network device;

[0047] sending a terminal access request response message to the first network device, the terminal access request response message comprising an estimated timing advance of the second network device.

[0048] The estimated timing advance of the second network device is obtained according to position information of the terminal.

[0049] In an implementation form, before the receiving the first preamble from the terminal, the method further comprises:

[0050] receiving a terminal access request message from the first network device;

[0051] sending a terminal access request response message to the first network device, the terminal access request response message comprising ephemeris information of the second network device.

[0052] In an implementation form, the terminal access request response message further comprises a system message of the second network device; wherein

[0053] The system message comprises preamble configuration information, the preamble configuration information being used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and a first sending time of the first preamble being one of the at least one random access occasion.

[0054] In an implementation form, the terminal access request response message further comprises preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and a first sending time of the first preamble being one of the at least one random access occasion.

[0055] In an implementation form, the terminal access request response message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, radio configuration information configured by the second network device for the terminal, frequency point information of the second network device, or preamble sequence number information; wherein

[0056] The preamble sequence number information is used to indicate the first preamble, and the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

[0057] In an implementation form, after receiving the first message on a physical uplink shared channel (PUSCH) corresponding to the first preamble according to the timing offset information, the method further comprises:

[0058] sending a first time advance to the terminal.

[0059] In an implementation form, the orbit height of the first network device is different from the orbit height of the second network device.

[0060] In a third aspect, a communication method is provided, applied to a first network device, and the method comprises:

[0061] sending a third message to a terminal, the third message comprising information used by the terminal to determine an estimated time advance of the second network device, the information used by the terminal to determine the estimated time advance of the second network device comprising at least one of an estimated time advance of the second network device or ephemeris information of the second network device.

[0062] The third message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information; wherein,

[0063] The preamble sequence number information is used to indicate a first preamble, and the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reassigned to the terminal by the second network device.

[0064] In an implementation manner, the third message further comprises system information of the second network device; wherein,

[0065] The system information comprises preamble configuration information, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion.

[0066] In an implementation manner, the third message further comprises preamble configuration information; wherein, the preamble configuration information is used to indicate at least one preamble and at least one random access occasion.

[0067] In an implementation manner, before the third message is sent to the terminal, the method further comprises:

[0068] receiving a second message from the terminal;

[0069] sending a terminal access request message to the second network device;

[0070] receiving a terminal access request response message from the second network device, the terminal access request response message comprising an estimated time advance of the second network device.

[0071] In an implementation manner, before the third message is sent to the terminal, the method further comprises:

[0072] receiving a second message from the terminal;

[0073] sending a terminal access request message to the second network device;

[0074] receiving a terminal access request response message from the second network device, the terminal access request response message comprising ephemeris information of the second network device.

[0075] In an implementation manner, the terminal access request response message further comprises: system information of the second network device; wherein,

[0076] The system message comprises preamble configuration information, the preamble configuration information being used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and a first sending time of the first preamble being one of the at least one random access occasion.

[0077] In an implementation, the terminal access request response message further comprises preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and a first sending time of the first preamble being one of the at least one random access occasion.

[0078] In an implementation, the terminal access request response message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information; wherein,

[0079] The preamble sequence number information is used to indicate the first preamble, and the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reassigned to the terminal by the second network device.

[0080] In an implementation, the second message comprises at least one of the following parameters: location information of the terminal, preset network device information, or service type information.

[0081] In an implementation, the second message is one of the following: an RRC connection establishment request message, an RRC reestablishment request message, a handover request message, or a redirection request message.

[0082] In an implementation, the third message is one of the following: an RRC connection establishment message, an RRC connection reestablishment message, a handover command message, or a redirection command message. In an implementation, an orbital height of the first network device is different from an orbital height of the second network device.

[0083] In a fourth aspect, a communication apparatus is provided, which is applied to a terminal, the terminal camping on a first network device, and the apparatus comprises:

[0084] A sending module is configured to send a first preamble to a second network device at a first sending time in advance of a predicted time advance of the second network device;

[0085] The sending module is further configured to send a first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble at a second sending time, where the second sending time is separated from the first sending time by a first preset time, and the first message is sent at the second sending time with the estimated time advance of the second network device.

[0086] The receiving module is configured to receive a first preamble from a terminal, where the terminal is camped on a first network device, and the first preamble is sent at a first sending time with an estimated time advance of a second network device.

[0087] The processing module is configured to determine timing offset information according to an actual receiving time window of the first preamble, where the timing offset information is used to indicate a time offset between the actual receiving time window of the first preamble and a preset receiving time window of the first preamble.

[0088] The receiving module is further configured to receive a first message on a physical uplink shared channel (PUSCH) corresponding to the first preamble according to the timing offset information, where the first message is sent at a second sending time with the estimated time advance of the second network device, and the second sending time is separated from the first sending time by a first preset time on the PUSCH.

[0089] In a sixth aspect, a communication apparatus is provided, which is applied to a first network device, and includes:

[0090] The sending module is configured to send a third message to a terminal, where the third message includes information used by the terminal to determine an estimated time advance of a second network device, and the information used by the terminal to determine the estimated time advance of the second network device includes at least one of the estimated time advance of the second network device or ephemeris information of the second network device.

[0091] The third message further includes at least one of the following parameters: a first temporary terminal identifier of the terminal, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information used to transmit the first message, subcarrier spacing information of the second network device, or preamble sequence number information; where

[0092] The preamble sequence number information is used to indicate a first preamble, and the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

[0093] In a seventh aspect, a terminal is provided, which includes a processor and a memory connected to the processor in communication.

[0094] The memory stores computer-executable instructions;

[0095] The processor executes the computer-executable instructions stored in the memory to implement the method in the first aspect and the implementation manners of the first aspect.

[0096] An eighth aspect provides a second network device, comprising a processor and a memory connected with the processor in communication;

[0097] The memory stores computer-executable instructions;

[0098] The processor executes the computer-executable instructions stored in the memory to implement the method in the second aspect and the implementation manners of the second aspect.

[0099] A ninth aspect provides a first network device, comprising a processor and a memory connected with the processor in communication;

[0100] The memory stores computer-executable instructions;

[0101] The processor executes the computer-executable instructions stored in the memory to implement the method in the third aspect and the implementation manners of the third aspect.

[0102] A tenth aspect provides a computer-readable storage medium, the computer-readable storage medium storing computer-executable instructions, the computer-executable instructions being executed by a processor to implement the method in any one of the first aspect to the third aspect and the implementation manners of any one of the first aspect to the third aspect.

[0103] An eleventh aspect provides a computer program product, comprising a computer program, the computer program being executed by a processor to implement the method in any one of the first aspect to the third aspect and the implementation manners of any one of the first aspect to the third aspect.

[0104] The communication method, device, terminal and network device provided in the present application, the terminal obtains the estimated time advance of the second network device before switching to the second network device through the first network device, and the terminal can perform uplink pre-synchronization with the second network device through the estimated time advance, so that the terminal sends the first preamble and the first message to the second network device through the estimated time advance of the second network device, so that the second network device can accurately receive the first message, accelerate the access process of the terminal to the second network device, and reduce the time delay of the terminal switching between base stations. BRIEF DESCRIPTION OF DRAWINGS

[0105] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments consistent with the application and, together with the description, further serve to explain the principles of the application.

[0106] Figure 1 is a communication system structure diagram according to an embodiment of the present application;

[0107] Figure 2 is a flow diagram of a communication method according to an embodiment of the present application;

[0108] Figure 3 is a flow diagram of a communication method according to another embodiment of the present application;

[0109] Figure 4 is a flow diagram of a communication method according to another embodiment of the present application;

[0110] Figure 5 is a flow diagram of a communication method according to another embodiment of the present application;

[0111] Figure 6 is a schematic block diagram of a communication apparatus according to an embodiment of the present application;

[0112] Figure 7 is a schematic block diagram of a communication apparatus according to another embodiment of the present application;

[0113] Figure 8 is a schematic block diagram of a communication apparatus according to another embodiment of the present application;

[0114] Figure 9 is a schematic block diagram of a communication apparatus according to an embodiment of the present application.

[0115] The specific embodiments of the present application have been shown by way of example in the above-described drawings and more details will be described hereinafter. These drawings and the written description are not intended to restrict the scope of the present application in any way but to explain the present application to those skilled in the art by reference to particular embodiments. DETAILED DESCRIPTION

[0116] The exemplary embodiments will be described in detail herein below with reference to the drawings. The following description is merely exemplary in nature and is not intended to limit the present application, application, or uses to any one particular embodiment described. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding background or the following detailed description.

[0117] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example, a Long Term Evolution (LTE) system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD), a Universal Mobile Telecommunication System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a future 5th Generation (5G) communication system or a new radio Access Technology (NR), vehicle-to-X (V2X), where V2X can include vehicle to network (V2N), vehicle to vehicle (V2V), vehicle to infrastructure (V2I), vehicle to pedestrian (V2P), etc., Long Term Evolution-Vehicle (LTE-V), vehicle networking, machine type communication (MTC), Internet of Things (IoT), Long Term Evolution-Machine (LTE-M), Machine to Machine (M2M), etc.

[0118] As shown in Figure 1 , the communication system can include network devices, for example, the network device 110 and the network device 120 as shown in Figure 1 ; the communication system can also include at least one terminal, for example, the terminal 130 as shown in Figure 1 . The terminal 130 can be mobile or fixed. The terminal 130 can access the network device 110 or the network device 120.

[0119] The network device 110 and the network device 120 in the embodiments of the present disclosure are an entity for transmitting or receiving signals on the network side, and the network device can be a network side device. For example, the network device 110 and the network device 120 can be an evolved NodeB (eNB), a transmission reception point (TRP), a next generation NodeB (gNB) in an NR system, a base station in other future mobile communication systems, or an access node in a wireless fidelity (WiFi) system, and the like. The embodiments of the present disclosure do not limit the specific technology and specific device form of the network device.

[0120] The network device 110 and the network device 120 provided by the embodiments of the present disclosure can be composed of a central unit (CU) and a distributed unit (DU), wherein the CU can also be referred to as a control unit. The CU-DU structure can split the protocol layer of the network device, for example, a base station, and place the functions of part of the protocol layer in the CU for centralized control, and distribute the functions of the remaining part or all of the protocol layer in the DU and control the DU centrally by the CU.

[0121] The terminal 130 in the embodiments of the present disclosure is an entity for receiving or transmitting signals on the user side, such as a mobile phone. The terminal can also be referred to as a terminal, a user equipment (UE), a mobile station (MS), a mobile terminal (MT), a user side device, and the like. The terminal can be a car with communication function, a smart car, a mobile phone, a wearable device, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, and the like.

[0122] In some embodiments, the network device 110 and the network device 120 can be satellites, such as the network device 110 and the network device 120 can be satellites in different orbits.

[0123] In some embodiments, the terminal 130 accesses the network device 110, and can camp on the network device 110, switch to access the network device 120, and communicate with the network device 120.

[0124] Embodiments of the present disclosure do not limit specific technologies and specific device forms adopted by the terminal / network device.

[0125] Embodiments of the present disclosure are not exhaustive, but only illustrate some embodiments, and are not specific limitations on the protection scope of the present disclosure. In the case of no contradiction, each step in an embodiment can be implemented as an independent embodiment, and the steps can be combined arbitrarily, for example, the scheme after removing some steps in an embodiment can also be implemented as an independent embodiment, and the order of the steps in an embodiment can be exchanged arbitrarily, in addition, the optional implementation manners in an embodiment can be combined arbitrarily; in addition, the embodiments can be combined arbitrarily, for example, the steps of different embodiments can be combined arbitrarily, an embodiment can be combined with the optional implementation manners of other embodiments arbitrarily. In each embodiment of the present disclosure, if there is no special description and logical conflict, the terms and / or descriptions between the embodiments are consistent, and can be referred to each other, and the technical features in different embodiments can be combined to form a new embodiment according to their inherent logical relationship.

[0126] It can be understood that the communication system described in the embodiments of the present disclosure is for more clearly illustrating the technical solutions of the embodiments of the present disclosure, and does not constitute a limitation on the technical solutions provided by the embodiments of the present disclosure. It can be known by those skilled in the art that, with the evolution of system architecture and the appearance of new business scenarios, the technical solutions provided by the embodiments of the present disclosure are also applicable to similar technical problems.

[0127] It can be understood that, in the embodiments of the present application, “for indicating” can include for directly indicating and for indirectly indicating, and can also include explicit indication and implicit indication. The information indicated by certain information is referred to as to-be-indicated information, and in the implementation process, there are many ways to indicate the to-be-indicated information, for example but not limited to, the to-be-indicated information can be directly indicated, such as the to-be-indicated information itself or an index of the to-be-indicated information. The to-be-indicated information can also be indirectly indicated by indicating other information, where the other information and the to-be-indicated information have an association relationship. The to-be-indicated information can also be indicated only by a part of the to-be-indicated information, and the other part of the to-be-indicated information is known or agreed in advance. For example, whether the to-be-indicated information is present can also be used to indicate the to-be-indicated information by means of pre-agreement (for example, agreement), thereby reducing the indication overhead to a certain extent.

[0128] It can be understood that, in the embodiments shown below, the first, second, and various numerical numbers are only distinguished for the convenience of description, and do not limit the scope of the embodiments of the present application. For example, different indication information, different time intervals, and the like are distinguished.

[0129] It can be understood that the “preset value” can be implemented by pre-storing corresponding codes, tables or other information that can be used to indicate related information in the device (for example, including terminal equipment and IMS, P-CSCF), and the specific implementation manner of the present application is not limited. Wherein, “storing” can mean storing in one or more memories. One or more memories can be separately set, or can be integrated in a codec or decoder, a processor, or a communication device. One or more memories can be part of separate settings and part of integrated in the decoder, processor, or communication device. The type of memory can be any form of storage medium, which is not limited in the present application.

[0130] It can be understood that the “protocol” involved in the embodiments of the present application can refer to a standard protocol in the communication field, for example, can include an LTE protocol, an NR protocol, and a related protocol applied to a future communication system, which is not limited in the present application.

[0131] It can be understood that "at least one" means one or more, and "multiple" means two or more. The "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist together, and B exists 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 item or multiple items. For example, at least one of a, b and c can mean: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c. Where a, b and c can be single or multiple.

[0132] It can be understood that in the embodiments of the present application, the descriptions such as "when", "in the case of", "if" and "if" all refer to the objective situation that the device (such as a terminal device or a network device) will make corresponding processing, not limited to time, and also does not require the device (such as a terminal device or a network device) to have a judgment action when implemented, nor does it mean that there are other limitations.

[0133] It can be understood that, for the convenience of explaining the embodiments of the present application, the message names involved are the message names in NR in the case of no special description. However, it can be understood that these message names are only examples for easy understanding, and should not constitute any limitation on the present application. The present application does not exclude the possibility of defining other message names in future protocols to replace the message names listed in the present application to achieve the same or similar functions. In addition, the message names in NR are taken as examples to explain the embodiments of the present application, which should not constitute any limitation on the scenes to which the methods provided by the present application are applicable.

[0134] It can be understood that the embodiments are described in detail below in combination with the flowcharts, but it should be understood that these flowcharts and the related descriptions of their corresponding embodiments are only examples for easy understanding, and should not constitute any limitation on the present application. Each step in the flowchart does not necessarily have to be executed, for example, some steps can be skipped. Moreover, the execution order of each step is not fixed and unchangeable, and is not limited to that shown in the figure, and the execution order of each step should be determined by its function and inherent logic.

[0135] In addition, each element, each row, or each column in the table of the embodiments of the present disclosure can be implemented as an independent embodiment, and any combination of any element, any row, or any column can also be implemented as an independent embodiment.

[0136] The method provided by the embodiments of the present application will be described in detail below in combination with the drawings.

[0137] It should be understood that the following is only for the convenience of understanding and illustration, and the method provided by the embodiments of the present application is described in detail by taking the interaction between the terminal device and the network device as an example. However, this should not constitute any limitation on the execution subject of the method provided by the present application. For example, the terminal device shown in the following embodiments can be replaced by a component (such as a chip or a circuit) configured in the terminal device. The network device shown in the following embodiments can also be replaced by a component (such as a chip or a circuit) configured in the network device.

[0138] The embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided by the embodiments of the present application, as long as the execution subject can communicate according to the method provided by the embodiments of the present application by running the program in which the code of the method provided by the embodiments of the present application is recorded. For example, the execution subject of the method provided by the embodiments of the present application can be a terminal device or a network device, or a functional module in the terminal device or the network device that can call and execute the program.

[0139] In some embodiments, different network devices have different coverage ranges, and a terminal can switch from one network device to another network device. For example, in satellite communication, low earth orbit (LEO) satellites, medium earth orbit (MEO) satellites, and geostationary earth orbit (GEO) satellites, etc. Multi-orbit satellites can provide different coverage ranges. In this way, by virtue of the different coverage and delay characteristics of different orbit satellites, the terminal can flexibly switch between satellites in different orbits to ensure service continuity and match the required quality of service (QoS) requirements, thereby effectively improving the reliability and availability of communication and meeting the diversified business needs worldwide.

[0140] When the terminal switches between two network devices, there are multiple factors affecting the transmission delay, such as long signal propagation distance (such as high-orbit satellite propagation delay), signal processing time (demodulation, retuning, etc.), multi-hop transmission (signal needs to pass through multiple nodes), user device response time, and environmental factors (such as weather interference).

[0141] Based on this, the present application provides a communication method, device, terminal and network device, which can reduce the transmission delay caused by the switching of the terminal between different network devices.

[0142] Figure 2 is a flowchart of a communication method according to an embodiment of the present application, as shown in Figure 2 The communication method can include steps S201 to S205. The following will be described in detail Figure 2each step in the method.

[0143] S201, the terminal sends a second message to the first network device.

[0144] In some embodiments, the terminal camps on the first network device.

[0145] In some embodiments, the terminal accesses the first network device.

[0146] In some embodiments, the terminal camps on a network in which the first network device is located.

[0147] In some embodiments, the terminal completes registration with a core network corresponding to the first network device.

[0148] In some embodiments, the first network device receives the second message sent by the terminal.

[0149] In some embodiments, the second message includes at least one of location information of the terminal, preset network device information, or service type information.

[0150] In some embodiments, the preset network device information can be used to indicate a type of network device to which the terminal tends to access, and the first network device can determine the second network device according to the preset network device information. For example, if the preset network device information indicates a low-orbit satellite, the second network device can be a low-orbit satellite, and the terminal can access the second network device.

[0151] The service type information is used to indicate a type of service to be processed by the terminal, and the second network device can be determined according to the service type information, and the terminal can access the second network device.

[0152] The location information of the terminal can be used to determine a second network device that is closer to the specific terminal or can provide better quality service to the terminal, and the terminal can access the second network device.

[0153] In some embodiments, the second message is one of a radio resource control (RRC) setup request message, an RRC reestablishment request message, a handover request message, or a redirect request message.

[0154] For different second messages, the information carried by the second message can be the same or different.

[0155] In an embodiment, the second message is an RRC connection setup request message, and the second message comprises the location information of the terminal and the preset network device information.

[0156] In another embodiment, the second message is an RRC connection setup request message, and the second message comprises the location information of the terminal and the service type information.

[0157] In an embodiment, the second message is an RRC reestablishment request message, and the second message comprises the location information of the terminal and the preset network device information.

[0158] In another embodiment, the second message is an RRC reestablishment request message, and the second message comprises the location information of the terminal and the service type information.

[0159] In an embodiment, the second message is a handover request message, and the second message comprises the location information of the terminal and the preset network device information.

[0160] In another embodiment, the second message is a handover request message, and the second message comprises the location information of the terminal and the service type information.

[0161] In another embodiment, the second message is a handover request message, and the second message comprises the preset network device information of the terminal and the service type information.

[0162] In an embodiment, the second message is a redirection request message, and the second message comprises the service type information.

[0163] S202. The first network device sends a terminal access request message to the second network device.

[0164] In some embodiments, the first network device receives the second message, determines from the second message that the terminal needs to be redirected to the second network device, and then sends a terminal access request message to the second network device.

[0165] It can be understood that in some embodiments, the first network device can determine the second network device according to one or more of the location information of the terminal, the preset network device information, or the service type information.

[0166] In some embodiments, the first network device determines whether the terminal needs to be handed over according to the service type information, and then determines the second network device according to the location information of the terminal or the service type information.

[0167] In some embodiments, the second message can not carry the location information of the terminal, and the first network device can store the location information of the terminal when the terminal accesses, and then determine the second network device according to the location information of the terminal stored in the first network device.

[0168] In another embodiment, the second message can not carry the location information of the terminal, and the first network device can instruct the terminal to report the information of the terminal after determining that the terminal needs to be handed over to another network device. At this time, the second network device can be determined according to the location information of the terminal.

[0169] In some other embodiments, the first network device can also determine whether the terminal needs to be handed over according to the load of the first network device. For example, when the load of the first network device exceeds a certain value, the first network device determines that the terminal needs to be handed over, and determines the second network device according to one or more of the location information of the terminal, the preset network device information, or the service type information.

[0170] In some embodiments, the first network device and the second network device are satellites, and the orbital height of the first network device is different from the orbital height of the second network device.

[0171] In some embodiments, the orbital height of the first network device is greater than the orbital height of the second network device.

[0172] In some embodiments, the orbital height of the first network device is less than the orbital height of the second network device.

[0173] In some embodiments, the terminal access request message is used to indicate that the terminal requests to access the second network device.

[0174] In some embodiments, the terminal access request can include a temporary identifier of the terminal, which can be carried in a temporary CRNTI or a CRNTI of the first network device. The terminal interacts with the first network device according to the temporary identifier of the terminal.

[0175] In some embodiments, the terminal access request can include the location information of the terminal.

[0176] In some embodiments, the terminal access request can include a temporary mobile subscriber identity (5G-TMSI).

[0177] In some embodiments, the terminal access request message includes one or more of the temporary identifier of the terminal, the location information of the terminal, or the temporary mobile subscriber identity.

[0178] S203, the second network device sends a terminal access request response message to the first network device.

[0179] In some embodiments, the second network device receives the terminal access request message sent by the first network device.

[0180] In some embodiments, the first network device receives the terminal response message. In some embodiments, the first network device receives the terminal response message.

[0181] In some embodiments, the second network device determines whether to allow the terminal to access the second network device according to a load status of the second network device, an access policy, and the like.

[0182] In some embodiments, the second network device sends, in a case where it is determined to allow the terminal to access, a terminal access request response message to the first network device.

[0183] In some embodiments, the second network device sends, in a case where it is determined not to allow the terminal to access, a terminal access request response message to the first network device, to indicate to the first network device that the second network device does not allow the terminal to access.

[0184] In some embodiments, the terminal access request response message includes a first temporary terminal identifier of the terminal.

[0185] The first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

[0186] The terminal can subsequently interact with the second network device according to the first temporary terminal identifier.

[0187] In some embodiments, if the temporary identifier allocated to the terminal by the first network device is different from the temporary identifier already allocated by the second network device, the first temporary terminal identifier can be the temporary identifier allocated to the terminal by the first network device.

[0188] In some embodiments, if the temporary identifier allocated to the terminal by the first network device is the same as the temporary identifier already allocated by the second network device, the first temporary terminal identifier can be the temporary identifier reallocated to the terminal by the second network device.

[0189] In some embodiments, the terminal access request response message includes a timing advance (TA) of the second network device, which is obtained by the second network device according to position information of the terminal.

[0190] The timing advance is an initial timing advance for subsequent transmission of the terminal at the second network device, and the terminal can use the timing advance for message transmission when sending a message to the second network.

[0191] In some embodiments, the second network device can determine the timing advance according to artificial intelligence or big data statistics, such as determining a TA with a low bit error rate used by other terminals in a similar position to the position corresponding to the position information of the terminal as the timing advance of the terminal.

[0192] In some embodiments, the terminal access request response message can comprise ephemeris information of the second network device, which can be used by the terminal to determine the estimated time advance and can also be used by the terminal to quickly search for and access the second network device.

[0193] In some embodiments, the terminal access request response message can comprise the estimated time advance of the second network device and the ephemeris information of the second network device.

[0194] In some embodiments, the terminal access request response message can comprise frequency point information of the second network device, which can be an Absolute Radio Frequency Channel Number (ARFCN) of the second network device, and the frequency point information of the second network device is used to indicate the frequency point currently supported by the network device, so as to facilitate the terminal to quickly access the second network device according to the frequency point information.

[0195] In some embodiments, the terminal access request response message can comprise Physical Uplink Shared Channel (PUSCH) configuration information, which is PUSCH configuration information used to transmit a first message, and the first message is a message transmitted by the terminal after sending a first preamble to the second network device.

[0196] In some embodiments, the PUSCH configuration information can comprise RV (redundancy version), modulation and coding scheme of the PUSCH.

[0197] Through the PUSCH configuration information, it can be determined how the terminal transmits the first message on the PUSCH.

[0198] In some embodiments, the terminal access request response message can comprise Subcarrier Spacing (SCS) information of the second network device, and the subcarrier spacing information can comprise time-frequency resource granularity that can be supported by the second network device, such as 15 kHz (kilohertz), 30 kHz, 60 kHz, etc., and through the subcarrier spacing information, low-latency information transmission between the terminal and the second network device can be realized.

[0199] It can be understood that when the terminal cannot determine the subcarrier spacing information of the second network device, the UE attempts blind search with different subcarrier spacings at each synchronization raster position until a valid Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) are found, the identity of the second network device is acquired, and the PBCH (Physical Broadcast Channel) and System Information Block Type 1 (SIB1) of the second network device are decoded.

[0200] In some embodiments, the terminal access request response message can include preamble index information (redirectPreamble Index) used by the terminal to determine the first preamble transmitted to the second network device.

[0201] In some embodiments, the terminal access request response message can include preamble configuration information, which is configuration information of the preamble used between the terminal and the second network device, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and the transmission time of the first preamble being one of the at least one random access occasion.

[0202] In some embodiments, the first preamble can be determined from the preamble index information in the at least one preamble, and the first preamble is the preamble sent by the terminal to the network device.

[0203] In some embodiments, the preamble configuration information can be the same as the configuration of random access, or the preamble configuration information can be different from the configuration of random access, or the preamble configuration information can be part of the configuration of random access.

[0204] In some embodiments, the terminal access request response message can include the SIB1 of the second network device.

[0205] In some embodiments, the SIB1 of the second network device can include the preamble configuration information.

[0206] In some embodiments, the SIB is Remaining Minimum SI (RMSI), that is, the remaining minimum system message other than the MIB

[0207] In some embodiments, the terminal access request response message can include the system message of the second network device.

[0208] In some embodiments, the system information of the second network device comprises a Master Information Block (MIB) and a SIB1 of the second network device.

[0209] In some embodiments, the terminal access request response message can comprise radio configuration information configured by the second network device for the terminal, and the radio configuration information can comprise Radio Bearer Config information and CellGroupConfig information.

[0210] In some embodiments, the radio configuration information is used to configure a communication resource and a behavior between the terminal and the second network device.

[0211] In some embodiments, the terminal access request response message comprises an estimated time advance or ephemeris information of the second network device.

[0212] In some embodiments, the terminal access request response message comprises at least one of the following: system information of the second network device, radio configuration information configured by the second network device for the terminal, frequency point information of the second network device, and a first temporary terminal identifier of the terminal, which is the same as a temporary identifier allocated to the terminal by the first network device or a temporary identifier re-allocated to the terminal by the second network device.

[0213] In some embodiments, the terminal access request response message comprises at least one of the following: PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information.

[0214] S204, the first network device sends a third message to the terminal.

[0215] In some embodiments, the first network device sends the third message to the terminal after receiving the access response message.

[0216] In some embodiments, the third message is the same as the information comprised in the access response message.

[0217] In some embodiments, the first network device sends the third message to the terminal according to the information comprised in the access response message.

[0218] In some embodiments, the third message comprises information for the terminal to determine an estimated time advance of the second network device.

[0219] In some embodiments, the third message comprises an estimated time advance of the second network device, i.e., the information for the terminal to determine an estimated time advance of the second network device comprises the estimated time advance.

[0220] In some embodiments, the third message can comprise ephemeris information of the second network device, which can be used by the terminal to determine the estimated time advance, i.e., the information used by the terminal to determine the estimated time advance of the second network device comprises ephemeris information of the second network device, which can also be used by the terminal to quickly search for and access the second network device.

[0221] In some embodiments, the terminal access request response message can comprise the estimated time advance of the second network device and the ephemeris information of the second network device.

[0222] In some embodiments, the third message can comprise frequency point information of the second network device.

[0223] In some embodiments, the third message can comprise PUSCH configuration information.

[0224] In some embodiments, the third message can comprise subcarrier spacing information of the second network device.

[0225] In some embodiments, the third message can comprise preamble index information (redirect PreambleIndex) used by the terminal to determine the first preamble transmitted to the second network device.

[0226] In some embodiments, the third message can comprise preamble configuration information, which is configuration information of a preamble used between the terminal and the second network device, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and the first sending time of the first preamble is one of the at least one random access occasion.

[0227] In some embodiments, the third message can comprise SIB1 of the second network device.

[0228] In some embodiments, the SIB1 of the second network device can comprise preamble configuration information.

[0229] In some embodiments, the third message of the terminal can comprise system messages of the second network device.

[0230] In some embodiments, the system messages of the second network device comprise MIB and SIB1 of the second network device.

[0231] In some embodiments, the system messages of the second network device are sent to the terminal through the terminal access request response message and the third message, which can accelerate the access process of the terminal to the second network device.

[0232] In some embodiments, the third message can comprise wireless configuration information configured by the second network device for the terminal.

[0233] In some embodiments, the third message comprises an estimated time advance or ephemeris information of the second network device.

[0234] In some embodiments, the third message comprises at least one of system information of the second network device, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, a first temporary terminal identifier of the terminal, the first temporary terminal identifier being the same as a temporary identifier allocated to the terminal by the first network device or a temporary identifier reallocated to the terminal by the second network device.

[0235] In some embodiments, the third message comprises at least one of PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device or preamble sequence number information.

[0236] It can be understood that the specific description of the information comprised in the third message can refer to the specific description of the information comprised in the terminal access request response message, which is not repeated here.

[0237] S205, the terminal sends the first preamble and the first message to the second network device.

[0238] In some embodiments, the terminal receives the third message and determines the first preamble according to the third message.

[0239] In some embodiments, the terminal determines the first preamble according to the preamble configuration information.

[0240] In some embodiments, the terminal determines the first preamble according to the preamble sequence number information.

[0241] In some embodiments, the terminal transmits the first preamble and the first message according to at least one of the subcarrier spacing information of the second network device, the PUSCH configuration information, the wireless configuration information, the frequency point information of the second network device.

[0242] In some embodiments, the terminal transmits the first message on the PUSCH according to the PUSCH configuration information for transmitting the first message.

[0243] In some embodiments, before the terminal sends the first preamble and the first message to the second network device, the terminal can also receive system information broadcast by the second network device, and the preamble configuration information can be determined through the system information broadcast by the second network device.

[0244] In some embodiments, the terminal can determine the preamble configuration information through the system information included in the third message; the terminal can also directly acquire the preamble configuration information through the third message; and the terminal can also receive the system information broadcast by the second network device to determine the preamble configuration information.

[0245] In some embodiments, the terminal determines the first sending time of the first preamble according to the random access occasion.

[0246] In some embodiments, the terminal determines the second sending time of the first message according to the PUSCH configuration information.

[0247] In some embodiments, the terminal sends the first preamble and the first message to the second network device according to the estimated time advance of the second network device.

[0248] In some embodiments, the third message includes the estimated time advance, and the terminal sends the first preamble and the first message to the second network device according to the estimated time advance of the second network device.

[0249] In some embodiments, the third message includes the ephemeris information of the second network device, the terminal determines the estimated time advance of the second network device based on the ephemeris information of the second network device, and then sends the first preamble and the first message to the second network device according to the estimated time advance of the second network device.

[0250] In some embodiments, the terminal sends the first preamble to the second network device at the first sending time in advance of the estimated time advance, and sends the first message to the second network device at the second sending time in advance of the estimated time advance.

[0251] In some embodiments, the terminal sends the first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble.

[0252] In some embodiments, the second sending time is separated from the first sending time by a first preset time.

[0253] In some embodiments, the second sending time is separated from the first sending time by a preset number of symbols on the PUSCH, and the preset number of symbols correspond to a length of the first preset time.

[0254] In some embodiments, the first preset time is predefined for the terminal, i.e., does not need to be indicated through signaling.

[0255] In some embodiments, the first preset time is sent by the first network device, and the first preset time can also be sent by the second network device to the terminal through the first network device, for example, the second network device sends the first preset time to the first network device, and the first network device sends the first preset time sent by the second network device to the terminal.

[0256] In some embodiments, the first network device can configure the interval between the first sending time and the second sending time, that is, the first preset time.

[0257] In some embodiments, the first preset time is carried in the third message.

[0258] In some embodiments, the first sending time is earlier than the second sending time.

[0259] In some embodiments, by setting the second sending time to be the first sending time plus the first preset time, the second network device can receive the first preamble first, so that the position of the PUSCH receiving window can be adjusted according to the timing offset information of the first preamble, thereby achieving accurate PUSCH synchronization and accurate reception of the first message.

[0260] In some embodiments, the timing offset information is used to indicate the time offset between the actual receiving time window of the first preamble and the preset receiving time window of the first preamble.

[0261] In some embodiments, the second network device receives the first preamble and can determine the actual receiving time window of the first preamble.

[0262] In some embodiments, the terminal sends the first preamble to the second network device, and the first preamble has a corresponding preset receiving time window.

[0263] In some embodiments, the timing offset information can be determined according to the preset receiving time window of the first preamble and the actual receiving time window of the first preamble, so that the time offset between the preset receiving time window of the first message and the actual receiving time window of the first message can be determined according to the timing offset information, that is, the timing offset information can also be regarded as the time offset between the preset receiving time window of the first message and the actual receiving time window of the first message, so that the actual receiving time window of the first message can be determined according to the preset receiving time window of the first message and the timing offset information, and the first message can be received in the actual receiving time window of the first message.

[0264] In some embodiments, the first message is one of: an RRC setup complete message, an RRC Reestablishment complete message, a handover complete message, an RRC reconfiguration complete message, or a Redirect complete message.

[0265] In some embodiments, the second network device receives the first message, and identifies that the terminal accesses the second network device, and the terminal can subsequently complete the service by interacting with the second network device.

[0266] In some embodiments, after the terminal accesses the second network device, the terminal can receive the first time advance sent by the second network device, and subsequently interacts with the second network device by using the first time advance.

[0267] In some embodiments, the second network device receives the first message, and sends the first time advance to the terminal, so as to achieve accurate synchronization by using the first time advance.

[0268] In some embodiments, the first time advance can be carried in a Physical Downlink Control Channel (PDCCH) message or a Physical Downlink Shared Channel (PDSCH) message of the second network device, or is carried in a Timing Advance Command MAC CE (Timing Advance Command MAC Control Element) message of the PDSCH sent by the second network device, and the first time advance indicates the terminal to perform uplink synchronization.

[0269] In the embodiments of the present application, before the terminal switches to the second network device through the first network device, the terminal acquires an estimated time advance of the second network device, and the terminal performs pre-synchronization with the second network device by using the estimated time advance, so that the terminal sends a first preamble and a first message to the second network device by using the estimated time advance of the second network device, so that the second network device can accurately receive the first message, and the access process of the terminal to the second network device is accelerated.

[0270] In an embodiment, the terminal sends the first preamble before sending the first message, and the second network device can acquire timing offset information according to the first preamble, so as to adjust the position of the first message receiving window by using the timing offset information, to achieve accurate synchronization, and further improve the success rate of receiving the first message.

[0271] and after sending the first message, the terminal further receives a first time advance of the second network device, so as to realize accurate uplink synchronization on the second network device after accessing the second network device.

[0272] It can be understood that in some embodiments, Figure 2 Steps S201 to S204 in the method are optional, and the terminal can acquire the estimated time advance of the second network device through other manners, and send the first preamble and the first message to the second network device according to the estimated time advance.

[0273] Figure 3 is a flowchart of a communication method according to another embodiment of the present application. It should be noted that the communication method in the embodiment is executed by a terminal. The terminal can be implemented by software and / or hardware.

[0274] As shown in Figure 3 , the communication method can include steps S301 to S302. Each step in the method will be described in detail below. Figure 3

[0275] S301, at a first sending time, sending a first preamble to a second network device, where a time advance of the second network device is estimated.

[0276] In some embodiments, the terminal camps on the first network device.

[0277] In some embodiments, the terminal accesses the first network device.

[0278] In some embodiments, the terminal camps on a network where the first network device is located.

[0279] In some embodiments, the terminal completes registration with a core network corresponding to the first network device at the first network device.

[0280] In some embodiments, the terminal sends the first preamble and the first message to the second network device according to the estimated time advance.

[0281] In some embodiments, the terminal performs uplink synchronization with the second network device according to the estimated time advance.

[0282] In some embodiments, the terminal first sends the first preamble to the second network device, and then sends the first message to the second network device, so that the second network device can adjust the receiving window of the first message according to the first preamble, and accurately receive the first message.

[0283] In some embodiments, the estimated time advance can be sent to the terminal by the second network device, or can be calculated by the terminal according to ephemeris information of the second network device. ​

[0284] In some embodiments, the second network device sends the estimated time advance to the terminal through the first network device.

[0285] S302, at the second sending time, the terminal sends the first message to the second network device with the estimated time advance.

[0286] It can be understood that the above related implementation of the terminal sending the first preamble and the first message to the second network device can refer to step S205 and its related implementation, which will not be repeated here.

[0287] In an implementation, the terminal sends the first preamble to the second network device at the first sending time with the estimated time advance, and sends the first message to the second network device at the second sending time with the estimated time advance.

[0288] In some embodiments, the first sending time is the sending time of the first preamble, which can be a pre-set time or a time negotiated between the second network device and the terminal, such as a certain time in the random access occasion of the preamble.

[0289] In some embodiments, the second sending time is the sending time of the first message, which can be a pre-set time or a time negotiated between the second network device and the terminal.

[0290] In some embodiments, the second sending time is separated from the first sending time by a first preset time.

[0291] In an implementation, the first preset time is predefined, or the first preset time is sent by the first network device.

[0292] It can be understood that the above related description of the first sending time and the second sending time can refer to the description of the first sending time and the second sending time in step S205, which will not be repeated here.

[0293] In an implementation, the orbit height of the first network device is different from the orbit height of the second network device.

[0294] The orbit height of the first network device is different from the orbit height of the second network device, and the coverage range of the first network device is different from the coverage range of the second network device, so that the terminal can quickly switch between the first network device and the second network device.

[0295] The terminal, when camping on the first network device, needs to perform handover according to service requirements or overloading of the first network device or other related reasons, so as to send the first preamble and the first message to the second network device by determining the estimated timing advance of the second network device, and thereby quickly switch to the second network device.

[0296] In an implementation, the terminal sends the first preamble to the second network device according to the preamble configuration information, the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and the first sending time of the first preamble is one of the at least one random access occasion.

[0297] In some embodiments, the terminal can receive the preamble configuration information, and determine the first preamble and the first sending time of the first preamble by the preamble configuration information, so as to send the first preamble by the preamble configuration information.

[0298] In some embodiments, the preamble configuration information can be sent to the terminal by the second network device.

[0299] In some embodiments, the second network device can send the preamble configuration information by broadcasting a system message, and the preamble configuration information is included in the system message, so that the terminal obtains the preamble configuration information according to the broadcasted system message.

[0300] In some embodiments, the second network device can send the preamble configuration information to the terminal through the first network device, for example, as described in the related embodiments in the Figure 2 The second network device sends a terminal access request response message to the first network device, the terminal access request response message includes the preamble configuration information, the first network device receives the terminal access request response message, and sends a third message to the terminal, the third message includes the preamble configuration information, so that the terminal obtains the preamble configuration information according to the third message.

[0301] In some embodiments, the second network device can send the preamble configuration information to the terminal through the first network device, for example, as described in the related embodiments in the Figure 2 The second network device sends a terminal access request response message to the first network device, the terminal access request response message includes a system message of the second network device, and the system message of the second network device includes the preamble configuration information, the first network device receives the terminal access request response message, and sends a third message to the terminal, the third message includes the system message of the second network device, and the system message of the second network device includes the preamble configuration information, so that the terminal obtains the preamble configuration information according to the system message in the third message.

[0302] ​​It can be understood that the related description of the preamble configuration information can refer to the related description of the preamble configuration information in steps S203, S204 and S205, and details are not described herein.

[0303] In an implementation, the terminal sends the first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble.

[0304] In some embodiments, the terminal can receive PUSCH configuration information sent by the second network device, and transmit the first message according to the PUSCH configuration information.

[0305] It can be understood that, since the first sending time and the second sending time are separated by a first preset time, the first preamble is first sent on the PUSCH, and after the first preset time, the first message is sent on the PUSCH.

[0306] In an implementation, the first message is one of the following: a radio resource control (RRC) connection setup complete message, an RRC reestablishment complete message, a handover complete message, an RRC reconfiguration complete message, or a redirection complete message.

[0307] In some embodiments, the terminal indicates to the second network device that the terminal accesses the second network device by sending the first message.

[0308] In an implementation, after sending the first message, the terminal can receive a first timing advance from the second network device.

[0309] In some embodiments, the second network device receives the first message and determines that the terminal accesses the second network device, and the second network device can send the first timing advance to the terminal, and the terminal can subsequently perform accurate uplink synchronization with the second network device according to the first timing advance.

[0310] In an implementation, before sending the first preamble and the first message to the second network device according to the estimated timing advance of the second network device, the terminal sends a second message to the first network device, and the terminal receives a third message from the first network device, and the third message includes the estimated timing advance.

[0311] When the terminal has a service, the terminal can send a second message to the first network device to which the terminal is camped, to inform the first network device that the terminal requests to access for the service.

[0312] The first network device can respond to the second message and determine that the terminal can access the second network device, and send an estimated timing advance to the terminal through a third message, so that the terminal can obtain the estimated timing advance of the second network device.

[0313] It can be understood that the related description of the second message can refer to the related description of the second message in step S201, and details are not described herein.

[0314] In an implementation, the third message includes wireless configuration information configured by the second network device for the terminal.

[0315] In some embodiments, the wireless configuration information is used to configure a communication resource and behavior between the terminal and the second network device.

[0316] It can be understood that the specific description of the wireless configuration information can refer to the related description of the wireless configuration information in steps S203 and S204, and details are not described herein.

[0317] In an implementation, the third message further includes frequency point information of the second network device.

[0318] In some embodiments, the frequency point information of the second network device is used to indicate a frequency point currently supported by the network device, so as to facilitate the terminal to quickly access the second network device according to the frequency point information.

[0319] It can be understood that the specific description of the frequency point information can refer to the related description of the frequency point information in steps S203 and S204, and details are not described herein.

[0320] In an implementation, the third message further includes a first temporary terminal identifier of the terminal, the first temporary terminal identifier being the same as a temporary identifier allocated to the terminal by the first network device or being a temporary identifier reallocated to the terminal by the second network device.

[0321] In some embodiments, the terminal can subsequently interact with the second network device according to the first temporary terminal identifier.

[0322] It can be understood that the specific description of the first temporary terminal identifier can refer to the related description of the first temporary terminal identifier in steps S203 and S204, and details are not described herein.

[0323] In an implementation, the preamble configuration information is acquired by one of the following manners: receiving a system message broadcast by the second network device, the system message including the preamble configuration information; the third message further including a system message of the second network device, the system message including the preamble configuration information; or the third message further including the preamble configuration information.

[0324] In an implementation, the third message further includes at least one of the following parameters: ephemeris information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information, the preamble sequence number information being used to indicate the first preamble.

[0325] It can be understood that the specific description of the third message can refer to the related description of the third message in steps S204 and S205, and details are not described herein.

[0326] In an implementation, before sending the first preamble and the first message to the second network device according to the estimated time advance of the second network device, the terminal sends a second message to the first network device; receives a third message from the first network device, the third message including ephemeris information of the second network device; and determines the estimated time advance of the second network device based on the ephemeris information of the second network device.

[0327] In some embodiments, the ephemeris information is included in the third message, and in this case, the terminal can directly calculate the estimated time advance of the second network device according to the ephemeris information.

[0328] In an implementation, when the third message includes the ephemeris information, the terminal obtains the preamble configuration information in one of the following manners: receiving a system message broadcast by the second network device, the system message including the preamble configuration information; the third message further including a system message of the second network device, the system message including the preamble configuration information; or the third message further including the preamble configuration information.

[0329] In an implementation, when the third message includes the ephemeris information, the third message further includes at least one of the following parameters: wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, or a first temporary terminal identifier of the terminal, the first temporary terminal identifier being the same as a temporary identifier allocated to the terminal by the first network device or being a temporary identifier newly allocated to the terminal by the second network device.

[0330] In an implementation, when the third message includes the ephemeris information, the third message further includes at least one of the following parameters: PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information, the preamble sequence number information being used to indicate the first preamble.

[0331] In an implementation, the third message is one of the following: an RRC connection setup message, an RRC connection reestablishment message, a handover command message, or a redirection command message.

[0332] It can be understood that when the third message includes the ephemeris information, the specific description of the third message can refer to the related description of the third message in steps S204 and S205, and details are not described herein.

[0333] In an implementation, the second message includes at least one of the following parameters: position information of the terminal, preset network device information, or service type information.

[0334] In some embodiments, the second message of the terminal can comprise at least one of location information of the terminal, preset network device information or service type information, so that the first network device can determine whether the terminal needs to be handed over to the second network device according to at least one of the location information of the terminal, the preset network device information or the service type information.

[0335] In some embodiments, the first network device receives the second message of the terminal, and then determines that the terminal needs to be handed over to the second network device. The first network device can send a terminal access request message to the second network device, and receive a terminal access request response message fed back by the second network device, so as to determine the information in the third message according to the information in the terminal access response request message.

[0336] In an implementation manner, the second message is one of an RRC connection establishment request message, an RRC reestablishment request message, a handover request message or a redirection request message.

[0337] It can be understood that the specific description of the second message can refer to the related description of the second message in steps S201 and S202, which will not be repeated here.

[0338] It can be understood that the implementation manner in which the first network device determines whether the terminal accesses the second network device according to the second message can refer to the related description in steps S201 and S202, which will not be repeated here.

[0339] Figure 4 is a flowchart of a communication method according to another embodiment of the present application. It should be noted that the communication method in the present embodiment is executed by a first network device. The first network device can be implemented by software and / or hardware.

[0340] As shown in Figure 4 , the communication method can comprise steps S401 to S403. The steps in Figure 4 will be described in detail below.

[0341] S401, receiving a first preamble from a terminal; the terminal resides in a first network device, and the first preamble is sent at a first sending time in advance of a preset time advance of a second network device.

[0342] In some embodiments, the terminal resides in the first network device.

[0343] In some embodiments, the terminal accesses the first network device.

[0344] In some embodiments, the terminal resides in a network in which the first network device is located.

[0345] In some embodiments, the terminal sends the first preamble to the second network device according to the estimated time advance.

[0346] S402, determining timing offset information according to the actual receiving time window of the first preamble, the timing offset information being used to indicate a time offset between the actual receiving time window of the first preamble and the preset receiving time window of the first preamble.

[0347] In an implementable manner, the second network device receives the first preamble first.

[0348] The second network device determines timing offset information according to the actual receiving time window of the first preamble, the timing offset information being used to indicate a time offset between the actual receiving time window of the first preamble and the preset receiving time window of the first preamble; and receives the first message on a physical uplink shared channel (PUSCH) corresponding to the first preamble according to the timing offset information.

[0349] S403, receiving the first message on a physical uplink shared channel (PUSCH) corresponding to the first preamble according to the timing offset information.

[0350] In an implementable manner, the terminal sends the first message on the PUSCH corresponding to the first preamble, and the second network device receives the first message sent by the terminal on the PUSCH corresponding to the first preamble.

[0351] In some embodiments, the timing offset information can be determined according to the preset receiving time window of the first preamble and the actual receiving time window of the first preamble, so that a time offset between the preset receiving time window of the first message and the actual receiving time window of the first message can be determined according to the timing offset information, that is, the timing offset information can also be regarded as the time offset between the preset receiving time window of the first message and the actual receiving time window of the first message, so that the actual receiving time window of the first message can be determined according to the preset receiving time window of the first message and the timing offset information, and the first message can be received in the actual receiving time window of the first message.

[0352] It can be understood that the related implementation manners of the second network device receiving the first message according to the first preamble can refer to the related implementation manners of the first preamble and the first message in step S205, which will not be described herein.

[0353] In an implementable manner, the first preamble is sent at a first sending time with an estimated time advance, the first message is sent at a second sending time with the estimated time advance, and the second sending time is separated from the first sending time by a first preset time on the PUSCH.

[0354] In some embodiments, the second network device receives the first preamble first by setting the second sending time to be separated from the first sending time by a first preset time, so that the position of the PUSCH receiving window can be adjusted according to the timing offset information of the first preamble, thereby achieving accurate PUSCH synchronization and accurate reception of the first message.

[0355] In some embodiments, the terminal sends the first preamble and the first message to the second network device according to the estimated time advance.

[0356] In some embodiments, the second network device determines that the terminal accesses the second network device after receiving the first message.

[0357] It can be understood that the above-mentioned related implementation manners of the second network device receiving the first preamble and the first message sent by the terminal can refer to steps S205 and S301 and related implementation manners thereof, which will not be described herein.

[0358] In an implementation manner, the orbital height of the first network device is different from the orbital height of the second network device.

[0359] In some embodiments, the orbital height of the first network device is different from the orbital height of the second network device, and the coverage range of the first network device is different from the coverage range of the second network device, so that the terminal can perform fast switching between the first network device and the second network device, thereby making the terminal more efficient in performing services.

[0360] In an implementation manner, the first message is at least one of the following: an RRC connection setup complete message, an RRC reestablishment complete message, a handover complete message, an RRC reconfiguration complete message, or a redirection complete message.

[0361] In an implementation manner, before receiving the first preamble from the terminal, the method further includes: receiving, by the second network device, a terminal access request message from the first network device; and sending, by the second network device, a terminal access request response message to the first network device, the terminal access request response message including an estimated time advance of the second network device.

[0362] The estimated time advance of the second network device is obtained according to the position information of the terminal.

[0363] In an implementation manner, the terminal access request response message further includes a first temporary terminal identifier of the terminal, wherein the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier re-allocated to the terminal by the second network device.

[0364] In some embodiments, the terminal access request message is used to indicate that the terminal needs to access the second network device, and after the second network device determines that the terminal can access, the second network device feeds back information required by the terminal to access the second network device to the first network device through a terminal access request response message, such as an estimated time advance, and the first network device sends the estimated time advance carried in the terminal access request response message to the terminal, such as sending the estimated time advance carried in the terminal access request response message to the terminal through a third message, so that the terminal can determine the estimated time advance according to the information in the third message, and according to the estimated time advance of the second network device, the first network device sends the first preamble and the first message to the second network device.

[0365] In an implementable manner, before receiving the first preamble from the terminal, the second network device receives the terminal access request message from the first network device; and sends a terminal access request response message to the first network device, wherein the terminal access request response message includes ephemeris information of the second network device.

[0366] In an implementable manner, the terminal access request response message further includes a first temporary terminal identifier of the terminal, wherein the first temporary terminal identifier is the same as the temporary identifier allocated to the terminal by the first network device or is a temporary identifier re-allocated to the terminal by the second network device.

[0367] In some embodiments, the terminal access request message is used to indicate that the terminal needs to access the second network device, and after the second network device determines that the terminal can access, the second network device feeds back information required by the terminal to access the second network device to the first network device through a terminal access request response message, such as ephemeris information of the second network device, and the first network device sends the ephemeris information of the second network device carried in the terminal access request response message to the terminal, such as sending the ephemeris information of the second network device carried in the terminal access request response message to the terminal through a third message, so that the terminal can determine the ephemeris information of the second network device according to the information in the third message, and determine the estimated time advance according to the ephemeris information of the second network device, and according to the estimated time advance of the second network device, the first network device sends the first preamble and the first message to the second network device.

[0368] In an implementable manner, the terminal access request response message further includes system information of the second network device; wherein the system information includes preamble configuration information, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and the first sending time of the first preamble is one of the at least one random access occasion.

[0369] In an implementation, the terminal access request response message further comprises preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and the first sending time of the first preamble is one of the at least one random access occasion.

[0370] The preamble configuration information can be sent by the first network device to the terminal, and the terminal can determine the first preamble and the first sending time of the first preamble according to the preamble configuration information.

[0371] It can be understood that the related description of the preamble configuration information can refer to the related description of the preamble configuration information in steps S203, S204 and S205, which will not be repeated here.

[0372] In an implementation, the terminal access request response message further comprises at least one of the following parameters: PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, or preamble sequence number information used to indicate the first preamble.

[0373] In some embodiments, the terminal access request response message comprises ephemeris information of the second network device or an estimated time advance of the second network device, and further comprises at least one of the following parameters: PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, or preamble sequence number information.

[0374] It can be understood that the related description of the terminal access request response message can refer to the related description of the terminal access request response message in step S203, which will not be repeated here.

[0375] In an implementation, after receiving the first preamble and the first message from the terminal, the second network device sends a first time advance to the terminal.

[0376] The terminal can achieve accurate synchronization with the second network device through the first time advance.

[0377] Figure 5 is a flowchart of a communication method according to another embodiment of the present application. It should be noted that the communication method in the present embodiment is executed by a first network device. The first network device can be implemented by software and / or hardware.

[0378] As shown in Figure 5 , the communication method can comprise step S501. The following will be described in detailFigure 5 each step in the method.

[0379] S501, sending a third message to the terminal, the third message comprising information for the terminal to determine an estimated time advance of the second network device.

[0380] In some embodiments, the terminal camps on the first network device.

[0381] In some embodiments, the terminal accesses the first network device.

[0382] In some embodiments, the terminal camps on a network in which the first network device is located.

[0383] In some embodiments, the information for the terminal to determine the estimated time advance of the second network device comprises the estimated time advance of the second network device, and the first network device indicates the estimated time advance of the second network device to the terminal through the third message.

[0384] In some embodiments, the information for the terminal to determine the estimated time advance of the second network device comprises ephemeris information of the second network device, and the first network device indicates the estimated time advance of the second network device to the terminal through the third message. The terminal determines the estimated time advance of the second network device according to the third message, and sends the first preamble and the first message to the second network device according to the estimated time advance of the second network device.

[0385] In an implementation, the first network device has a different orbital height from the second network device.

[0386] In some embodiments, the first network device has a different orbital height from the second network device, and the first network device has a different coverage range from the second network device. The terminal can perform fast switching between the first network device and the second network device, so that the terminal can perform services more efficiently.

[0387] In an implementation, the third message comprises the estimated time advance of the second network device for the terminal to determine the estimated time advance of the second network device, i.e., the information for the terminal to determine the estimated time advance of the second network device comprises the estimated time advance of the second network device; wherein the estimated time advance of the second network device is obtained according to position information of the terminal.

[0388] In an implementation, the third message further comprises a first temporary terminal identifier of the terminal, the first temporary terminal identifier being the same as a temporary identifier allocated to the terminal by the first network device or being a temporary identifier re-allocated to the terminal by the second network device.

[0389] In some embodiments, the terminal interacts with the second network device through the first temporary terminal identifier.

[0390] It can be understood that the specific description of the first temporary terminal identifier can refer to the related description of the first temporary terminal identifier in steps S203 and S204, and details are not described herein.

[0391] In some embodiments, the third message includes the estimated time advance, so that the terminal can directly obtain the estimated time advance through the third message.

[0392] In an embodiment, the second network device calculates the estimated time advance according to the position information of the terminal, and sends the estimated time advance to the terminal through the third message of the second network device.

[0393] In an implementable manner, the third message includes ephemeris information of the second network device, that is, ephemeris information of the second network device used by the terminal to determine the estimated time advance of the second network device.

[0394] In an implementable manner, the third message further includes the first temporary terminal identifier; wherein the first temporary terminal identifier is the same as the temporary identifier allocated to the terminal by the first network device or is the temporary identifier re-allocated to the terminal by the second network device.

[0395] In some embodiments, the third message includes ephemeris information of the second network device, and the terminal can calculate the estimated time advance according to the ephemeris information of the second network device.

[0396] In an implementable manner, the third message further includes system information of the second network device; wherein the system information includes preamble configuration information, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion.

[0397] In some embodiments, the system information of the second network device is carried by the third message, so as to realize fast reception of the system information of the second network device by the terminal and fast synchronization.

[0398] The preamble configuration information is further included in the system information of the second network device, so as to configure the first preamble sent by the terminal to the second network device through the preamble configuration information.

[0399] In an implementable manner, the third message further includes preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion.

[0400] In some embodiments, the preamble configuration information is carried by the third message, so as to configure the first preamble sent by the terminal to the second network device through the preamble configuration information.

[0401] In an implementation, the third message further comprises at least one of the following parameters: the first temporary terminal identifier of the terminal, the radio configuration information configured by the second network device for the terminal, the frequency point information of the second network device, the PUSCH configuration information for transmitting the first message, the subcarrier spacing information of the second network device, or the preamble sequence number information, the preamble sequence number information being used to indicate the first preamble.

[0402] In some embodiments, the preamble sequence number information is used to indicate the first preamble, and the first temporary terminal identifier is the same as the temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

[0403] In an implementation, the third message is one of the following: an RRC connection setup message, an RRC connection reestablishment message, a handover command message, or a redirection command message.

[0404] It can be understood that the related description of the third message can refer to the related description of the third message in steps S204 and S205, and will not be repeated here.

[0405] In an implementation, before sending the third message to the terminal, the first network device receives the second message from the terminal, and sends a terminal access request message to the second network device after receiving the second message.

[0406] In some embodiments, the first network device receives a terminal access request response message from the second network device after sending the terminal access request message, and the terminal access request response message comprises the estimated time advance of the second network device.

[0407] In an implementation, before sending the third message to the terminal, the first network device receives the second message from the terminal, the first network device sends a terminal access request message to the second network device, and the first network device receives a terminal access request response message from the second network device, the terminal access request response message comprising the ephemeris information of the second network device.

[0408] In some embodiments, the terminal needs to access the network device for service, and the terminal resides in the first network device, so as to send the second message to the first network device to indicate that the terminal needs to access the network device.

[0409] In an implementation, the second message comprises at least one of the following parameters: the location information of the terminal, the preset network device information, or the service type information.

[0410] The first network device can determine whether the terminal needs to be handed over to the second network device according to the second message, and after determining that the terminal needs to be handed over to the second network device, sends a terminal access request message to the second network device to indicate that the terminal needs to access the second network device.

[0411] The second network device feeds back a terminal access request response message to the first network device after determining that the terminal can access, and the first network device can determine the third message according to information carried in the terminal access request response message, so as to send information required by the terminal to access the second network device to the terminal, such as sending the estimated time advance or the ephemeris information of the second network device to the terminal.

[0412] In an implementation, the terminal access request response message further includes: the first temporary terminal identifier of the terminal, and system information of the second network device; the system information includes preamble configuration information, the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and the first sending time of the first preamble is one of the at least one random access occasion.

[0413] In some embodiments, the preamble sequence number information is used to indicate the first preamble, and the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier re-allocated to the terminal by the second network device.

[0414] In an implementation, the terminal access request response message further includes preamble configuration information; the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and the first sending time of the first preamble is one of the at least one random access occasion.

[0415] It can be understood that the related description of the preamble configuration information can refer to the related description of the preamble configuration information in steps S203, S204 and S205, and will not be repeated here.

[0416] In an implementation, the second message is one of the following: an RRC connection establishment request message, an RRC re-establishment request message, a handover request message or a redirection request message.

[0417] It can be understood that the related description of the second message can refer to the related description of the second message in step S201, and will not be repeated here.

[0418] In an implementation, the terminal access request response message further includes at least one of the following parameters: wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device or preamble sequence number information, the preamble sequence number information being used to indicate the first preamble.

[0419] It can be understood that the related description of the terminal access request response message can refer to the related description of the terminal access request response message in step S203, and details are not described here.

[0420] Figure 6 is a schematic block diagram of a communication apparatus according to an embodiment of the present application. As shown in Figure 6 the communication apparatus 600 can include a sending module 601.

[0421] In an embodiment, the communication apparatus 600 can be configured to implement the operations of the terminal in the above embodiments. In some embodiments, the communication apparatus 600 is a terminal, or a component such as a chip or circuit configured in the terminal.

[0422] The communication apparatus 600 can implement the corresponding operations of the terminal in the embodiments of the communication method as shown in Figures 2 to 5 The communication apparatus 600 can include modules for performing the methods performed by the terminal in the embodiments of the communication method as shown in Figures 2 to 5 The communication apparatus 600 can include modules for performing the methods performed by the terminal in the embodiments of the communication method as shown in Figures 2 to 5 The communication apparatus 600 can include modules for performing the methods performed by the terminal in the embodiments of the communication method as shown in

[0423] In some embodiments, the sending module 601 is configured to send a first preamble to the second network device at a first sending time, the first sending time being advanced by an estimated time advance of the second network device; and the sending module 601 is further configured to send a first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble at a second sending time, the second sending time being advanced by the estimated time advance, and the second sending time being separated from the first sending time by a first preset time.

[0424] In some embodiments, the terminal is camped on the first network device.

[0425] In an implementation, the sending module 601 is further configured to send the first preamble to the second network device according to preamble configuration information, the preamble configuration information being used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and the first sending time of the first preamble being one of the at least one random access occasion.

[0426] In an implementation, the first preset time is predefined, or the first preset time is sent by the first network device.

[0427] In an implementation, the first message is one of the following: a radio resource control (RRC) connection setup complete message, an RRC reestablishment complete message, a handover complete message, an RRC reconfiguration complete message, or a redirection complete message.

[0428] In an implementation, the communication apparatus 600 further includes a receiving module.

[0429] The sending module is further configured to send a second message to the first network device; and the receiving module is configured to receive a third message from the first network device, the third message including the estimated time advance.

[0430] In an implementation, the third message includes wireless configuration information configured by the second network device for the terminal.

[0431] In an implementation, the third message further includes frequency point information of the second network device.

[0432] In an implementation, the third message further includes a first temporary terminal identifier of the terminal, the first temporary terminal identifier being the same as a temporary identifier allocated to the terminal by the first network device or being a temporary identifier reallocated to the terminal by the second network device.

[0433] In an implementation, the preamble configuration information is obtained by one of the following manners: receiving a system message broadcast by the second network device, the system message including the preamble configuration information; the third message further including a system message of the second network device, the system message including the preamble configuration information; or the third message further including the preamble configuration information.

[0434] In an implementation, the third message further includes at least one of the following parameters: ephemeris information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information used for indicating the first preamble.

[0435] In an implementation, the receiving module is further configured to send a second message to the first network device; and the receiving module is further configured to receive a third message from the first network device, the third message including ephemeris information of the second network device.

[0436] The communication apparatus 600 further includes a processing module configured to determine the estimated time advance of the second network device based on the ephemeris information of the second network device.

[0437] In an implementation, the terminal obtains the preamble configuration information by one of the following manners: receiving a system message broadcast by the second network device, the system message including the preamble configuration information; the third message further including a system message of the second network device, the system message including the preamble configuration information; or the third message further including the preamble configuration information.

[0438] In an implementation, the third message further comprises at least one of the following parameters: wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, and a first temporary terminal identifier of the terminal, the first temporary terminal identifier being the same as a temporary identifier allocated to the terminal by the first network device or being a temporary identifier reallocated to the terminal by the second network device.

[0439] In an implementation, the third message further comprises at least one of the following parameters: PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information, the preamble sequence number information being used to indicate a first preamble.

[0440] In an implementation, the second message comprises at least one of the following parameters: location information of the terminal, preset network device information, or service type information.

[0441] In an implementation, the second message is one of the following: an RRC connection setup request message, an RRC reestablishment request message, a handover request message, or a redirection request message.

[0442] In an implementation, the third message is one of the following: an RRC connection setup message, an RRC connection reestablishment message, a handover command message, or a redirection command message.

[0443] In an implementation, the receiving module is further configured to receive a first time advance from the second network device.

[0444] In an implementation, the first network device is at a different altitude than the second network device.

[0445] Figure 7 is a schematic block diagram of a communication apparatus according to an embodiment of the present application. As shown in Figure 7 the communication apparatus 700 can include a receiving module 701 and a processing module 702.

[0446] In an embodiment, the communication apparatus 700 can be configured to implement operations corresponding to the second network device in the above-described embodiments. In some embodiments, the communication apparatus 700 is the second network device, or a component (such as a chip or circuit) configured in the second network device.

[0447] The communication apparatus 700 can implement the corresponding operations of the second network device in the embodiments of the communication method shown in Figures 2 to 5 The communication apparatus 700 can include modules for performing the methods performed by the second network device in the embodiments of the communication method shown in Figures 2 to 5 The communication apparatus 700 can include modules for performing the methods performed by the second network device in the embodiments of the communication method shown in Figures 2 to 5The corresponding flow in the illustrated communication method embodiment.

[0448] In some embodiments, the receiving module 701 is configured to receive a first preamble from a terminal, the terminal camping on a first network device, the first preamble being sent at a first sending time, the first sending time being a first sending time advanced by an estimated time advance of a second network device; the processing module 702 is configured to determine timing offset information according to an actual receiving time window of the first preamble, the timing offset information being used to indicate a time offset between the actual receiving time window of the first preamble and a preset receiving time window of the first preamble; and the receiving module 701 is further configured to receive a first message on a physical uplink shared channel (PUSCH) corresponding to the first preamble according to the timing offset information, the first message being sent at a second sending time, the second sending time being advanced by the estimated time advance, and the second sending time being separated from the first sending time by a first preset time on the PUSCH. In one implementation form, the first message is at least one of the following: an RRC connection setup complete message, an RRC reestablishment complete message, a handover complete message, an RRC reconfiguration complete message, or a redirection complete message.

[0449] In one implementation form, the receiving module 701 is further configured to receive a terminal access request message from the first network device; and the communication apparatus 700 further includes a sending module configured to send a terminal access request response message to the first network device, the terminal access request response message including an estimated time advance of the second network device; wherein the estimated time advance of the second network device is obtained according to location information of the terminal.

[0450] In one implementation form, the receiving module 701 is further configured to receive a terminal access request message from the first network device; and the sending module is further configured to send a terminal access request response message to the first network device, the terminal access request response message including ephemeris information of the second network device.

[0451] In one implementation form, the terminal access request response message further includes system information of the second network device; wherein the system information includes preamble configuration information, the preamble configuration information being used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and the first sending time of the first preamble being one of the at least one random access occasion.

[0452] In one implementation form, the terminal access request response message further includes preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and the first sending time of the first preamble being one of the at least one random access occasion.

[0453] In an implementation, the terminal access request response message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, or preamble sequence number information; wherein the preamble sequence number information is used to indicate a first preamble, the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reassigned to the terminal by the second network device.

[0454] In an implementation, the sending module is further configured to send a first time advance to the terminal.

[0455] In an implementation, the orbit height of the first network device is different from the orbit height of the second network device.

[0456] Figure 8 is a schematic block diagram of a communication apparatus according to an embodiment of the present application. As shown in Figure 8 the communication apparatus 800 can comprise a sending module 801.

[0457] In an embodiment, the communication apparatus 800 can be configured to implement the operations of the first network device in the above embodiments. In some embodiments, the communication apparatus 800 is the first network device, or a component (such as a chip or circuit) configured in the first network device.

[0458] The communication apparatus 800 can implement the corresponding operations of the first network device in the embodiments of the communication method shown in Figures 2 to 5 The communication apparatus 800 can comprise modules for performing the methods implemented by the first network device in the embodiments of the communication method shown in Figures 2 to 5 The communication apparatus 800 can comprise modules for performing the methods implemented by the first network device in the embodiments of the communication method shown in Figures 2 to 5 The communication apparatus 800 can comprise modules for performing the methods implemented by the first network device in the embodiments of the communication method shown in

[0459] In some embodiments, the sending module 801 is configured to send a third message to the terminal, the third message comprising information for the terminal to determine an estimated time advance of the second network device, the information for the terminal to determine the estimated time advance of the second network device comprising at least one of the estimated time advance of the second network device or ephemeris information of the second network device.

[0460] The third message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information of a PUSCH used for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information; wherein the preamble sequence number information is used to indicate a first preamble, the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

[0461] In an implementation manner, the third message further comprises system information of the second network device; wherein the system information comprises preamble configuration information, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion.

[0462] In an implementation manner, the third message further comprises preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion.

[0463] In an implementation manner, the communication apparatus 800 further comprises a receiving module, the receiving module is used to receive a second message from the terminal; the sending module 801 is further used to send a terminal access request message to the second network device; and the receiving module is further used to receive a terminal access request response message from the second network device, the terminal access request response message comprising an estimated time advance of the second network device; wherein the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

[0464] In an implementation manner, the receiving module is further used to receive a second message from the terminal; the sending module 801 is further used to send a terminal access request message to the second network device; and the receiving module is further used to receive a terminal access request response message from the second network device, the terminal access request response message comprising ephemeris information of the second network device.

[0465] In an implementation manner, the terminal access request response message further comprises: system information of the second network device; wherein the system information comprises preamble configuration information, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and a first sending time of the first preamble is one of the at least one random access occasion.

[0466] In an implementation manner, the terminal access request response message further comprises preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and a first sending time of the first preamble is one of the at least one random access occasion.

[0467] In an implementation, the terminal access request response message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information; wherein the preamble sequence number information is used to indicate a first preamble, the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

[0468] In an implementation, the second message comprises at least one of the following parameters: location information of the terminal, preset network device information, or service type information.

[0469] In an implementation, the second message is one of the following: an RRC connection establishment request message, an RRC reestablishment request message, a handover request message, or a redirection request message.

[0470] In an implementation, the third message is one of the following: an RRC connection establishment message, an RRC connection reestablishment message, a handover command message, or a redirection command message. In an implementation, the orbital height of the first network device is different from the orbital height of the second network device.

[0471] Figure 9 is a schematic block diagram of a communication device according to an embodiment of the present application. As shown in Figure 9 the communication device 900 can be a terminal; or a network device, such as a first network device, a second network device, etc., which is not specifically limited here, and the communication device 900 can be used to implement the methods described in the above method embodiments, and specific descriptions can be made by referring to the descriptions in the above method embodiments.

[0472] The communication device 900 comprises a processor 91 and a memory 92 connected with the processor 91.

[0473] The memory 92 is used to store computer execution instructions.

[0474] The processor 91 is used to execute the computer execution instructions stored in the memory, so as to enable the communication device 900 to perform the above method.

[0475] In some embodiments, the communication device 900 can further comprise a transceiver 93, which can comprise a transmitter and / or a receiver. The transmitter can also be referred to as a sender, a transmitter, a transmission port or a transmission interface, and the like. The receiver can also be referred to as a receiver, a receiving port or a receiving interface, and the like. Exemplarily, the memory 92, the processor 91 and the transceiver 93 are connected with each other through a bus 94.

[0476] The processor 90 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), or the like. The general-purpose processor can be a microprocessor or the like, or can also be any conventional processor. The steps of the method disclosed in the present application can be directly embodied as hardware processor execution, or executed by a combination of hardware and software modules in the processor.

[0477] In some embodiments, all or part of the memory 92 can also be outside the communication device 900.

[0478] In some embodiments, the communication device 900 is a terminal, and the terminal comprises a processor and a memory connected to the processor in communication; the memory stores computer execution instructions; and the processor executes the computer execution instructions stored in the memory to implement the communication method performed by the terminal as above.

[0479] In some embodiments, the communication device 900 is a second network device, and the second network device comprises a processor and a memory connected to the processor in communication; the memory stores computer execution instructions; and the processor executes the computer execution instructions stored in the memory to implement the communication method performed by the second network device as above.

[0480] In some embodiments, the communication device 900 is a first network device, and the first network device comprises a processor and a memory connected to the processor in communication; the memory stores computer execution instructions; and the processor executes the computer execution instructions stored in the memory to implement the communication method performed by the first network device as above.

[0481] The embodiments of the present application also provide a computer readable storage medium, and the computer readable storage medium stores computer execution instructions. When the computer execution instructions are executed by a processor, the computer execution instructions are used to implement the communication method shown in any of the embodiments as above.

[0482] The embodiments of the present application also provide a computer program product, and the computer program product comprises a computer program. When the computer program is executed by a processor, the computer program implements the communication method shown in any of the embodiments as above.

[0483] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0484] It is to be understood that the application is not limited to the precise construction herein disclosed and shown in the attached figures, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is limited only by the claims that follow.

Claims

1. A communication method characterized by comprising: The method is applied to a terminal, the terminal camps on a first network device, and the method comprises the following steps: sending a second message to the first network device; the second message is one of an RRC connection setup request message and an RRC reestablishment request message; receiving a third message from the first network device, wherein the third message comprises an estimated time advance of a second network device; sending a first preamble to the second network device at a first sending time in advance of the estimated time advance of the second network device, so that the second network device determines timing offset information according to an actual receiving time window of the first preamble, wherein the timing offset information is used to indicate a time offset between the actual receiving time window of the first preamble and a preset receiving time window of the first preamble; sending a first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble at a second sending time in advance of the estimated time advance; wherein the second sending time is separated from the first sending time by a first preset time on the PUSCH; the coverage range of the first network device is different from the coverage range of the second network device; and the first message is one of a radio resource control (RRC) connection setup complete message and an RRC reestablishment complete message.

2. The method of claim 1, wherein, The step of sending the first preamble to the second network device comprises the following steps: sending the first preamble to the second network device according to preamble configuration information, wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion; the first preamble is one of the at least one preamble; and the first sending time of the first preamble is one of the at least one random access occasion.

3. The method of claim 1, wherein, The first preset time is predefined, or the first preset time is sent by the first network device.

4. The method of claim 1, wherein, The third message comprises radio configuration information configured by the second network device for the terminal.

5. The method of claim 4, wherein, The third message further comprises frequency point information of the second network device.

6. The method of claim 1, wherein, The third message further comprises a first temporary terminal identifier of the terminal, wherein the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device.

7. The method according to any one of claims 4-6, characterized in that, The preamble configuration information is obtained in one of the following ways: receiving a system message broadcast by the second network device, wherein the system message comprises the preamble configuration information; The third message further comprises a system message of the second network device, wherein the system message comprises the preamble configuration information; The third message further comprises the preamble configuration information.

8. The method of claim 1, wherein, The third message further comprises at least one of the following parameters: ephemeris information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information used to indicate the first preamble.

9. The method of claim 1, wherein, Before the step of sending the first preamble to the second network device, the method further comprises the following steps: sending a second message to the first network device; receiving a third message from the first network device, the third message comprising ephemeris information of a second network device; determining an estimated time advance of the second network device based on the ephemeris information of the second network device.

10. The method of claim 9, wherein, The terminal obtains the preamble configuration information in one of the following manners: receiving a system message broadcast by the second network device, the system message comprising the preamble configuration information; The third message further comprises a system message of the second network device, and the system message comprises the preamble configuration information. The third message further comprises the preamble configuration information.

11. The method according to claim 9 or 10, characterized in that, The third message further comprises at least one of the following parameters: wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, and a first temporary terminal identifier of the terminal, which is the same as a temporary identifier allocated to the terminal by the first network device or a temporary identifier reallocated to the terminal by the second network device.

12. The method of claim 9, wherein, The third message further comprises at least one of the following parameters: PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information used to indicate the first preamble.

13. The method of claim 1, wherein, The second message comprises at least one of the following parameters: location information of the terminal, preset network device information, or service type information.

14. The method of claim 1, wherein, The third message is one of the following: an RRC connection establishment message, an RRC connection reestablishment message, a handover command message, or a redirection command message.

15. The method of claim 1, wherein, After the terminal sends the first message on the physical uplink shared channel (PUSCH) corresponding to the first preamble, the method further comprises: receiving a first time advance from the second network device.

16. The method of claim 1, wherein, The orbit height of the first network device is different from the orbit height of the second network device.

17. A method of communication, comprising: The method applied to the second network device comprises: receiving a terminal access request message from a first network device, wherein the terminal access request message is generated by the first network device after receiving a second message sent by a terminal; and the second message is one of the following: an RRC connection establishment request message and an RRC reestablishment request message; sending a terminal access request response message to the first network device, the terminal access request response message comprising an estimated time advance of the second network device; The estimated time advance of the second network device is obtained according to the location information of the terminal. receiving a first preamble from a terminal; the terminal resides in a first network device, and the first preamble is sent at a first transmission time advance of the estimated time advance of the second network device; the coverage range of the first network device is different from the coverage range of the second network device; determining timing offset information according to an actual reception time window of the first preamble, the timing offset information being used to indicate a time offset between the actual reception time window of the first preamble and a preset reception time window of the first preamble; and determining timing offset information according to an actual reception time window of the first preamble, the timing offset information being used to indicate a time offset between the actual reception time window of the first preamble and a preset reception time window of the first preamble; and receive a first message on a physical uplink shared channel (PUSCH) corresponding to the first preamble according to the timing offset information; the first message is sent at a second sending time, which is the first preset time away from the first sending time, and the first message is at least one of an RRC connection setup complete message and an RRC reestablishment complete message.

18. The method of claim 17, wherein, Before the receiving the first preamble from the terminal, the method further comprises: receiving a terminal access request message from the first network device; sending a terminal access request response message to the first network device, the terminal access request response message comprising ephemeris information of the second network device.

19. The method of claim 17 or 18, wherein, The terminal access request response message further comprises system information of the second network device; wherein The system information comprises preamble configuration information, the preamble configuration information being used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and the first sending time of the first preamble being one of the at least one random access occasion.

20. The method of claim 17 or 18, wherein, The terminal access request response message further comprises preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble being one of the at least one preamble, and the first sending time of the first preamble being one of the at least one random access occasion.

21. The method of claim 17 or 18, wherein, The terminal access request response message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, radio configuration information configured by the second network device for the terminal, frequency point information of the second network device, or preamble sequence number information; wherein The preamble sequence number information is used to indicate the first preamble, and the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reassigned to the terminal by the second network device.

22. The method of claim 17 or 18, wherein, After the receiving the first message on the PUSCH corresponding to the first preamble according to the timing offset information, the method further comprises: sending a first time advance to the terminal.

23. The method of claim 17 or 18, wherein, The orbit height of the first network device is different from the orbit height of the second network device.

24. A method of communication, comprising: The method applied to a first network device, the method comprising: receiving a second message from a terminal; the second message being one of an RRC connection setup request message and an RRC reestablishment request message; sending a terminal access request message to a second network device; receiving a terminal access request response message from the second network device; sending a third message to the terminal, so that the terminal sends a first preamble to the second network device according to the third message at a first sending time in advance of an estimated time advance of the second network device, so that the second network device determines timing offset information according to an actual receiving time window of the first preamble, wherein the timing offset information is used to indicate a time offset between the actual receiving time window of the first preamble and a preset receiving time window of the first preamble, sends a first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble at a second sending time in advance of the estimated time advance, wherein the second sending time is separated from the first sending time by a first preset time; and the first message is at least one of an RRC connection setup complete message and an RRC reestablishment complete message. The third message includes information used by the terminal to determine the estimated time advance of the second network device, and the information used by the terminal to determine the estimated time advance of the second network device includes at least one of the estimated time advance of the second network device or ephemeris information of the second network device; and the terminal camps on the first network device. The third message further includes at least one of the following parameters: a first temporary terminal identifier of the terminal, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information; wherein The preamble sequence number information is used to indicate the first preamble, the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device; and a coverage range of the first network device is different from a coverage range of the second network device.

25. The method of claim 24, wherein, The third message further includes system information of the second network device; wherein The system information includes preamble configuration information, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion.

26. The method of claim 24 or 25, wherein, The third message further includes preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion.

27. The method of claim 24, wherein, The terminal access request response message includes the estimated time advance of the second network device and ephemeris information of the second network device.

28. The method of claim 27, wherein, The terminal access request response message further includes system information of the second network device; wherein The system information includes preamble configuration information, and the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and a first sending time of the first preamble is one of the at least one random access occasion.

29. The method of claim 27, wherein, The terminal access request response message further comprises preamble configuration information; wherein the preamble configuration information is used to indicate at least one preamble and at least one random access occasion, the first preamble is one of the at least one preamble, and a first sending time of the first preamble is one of the at least one random access occasion.

30. The method of claim 27, wherein, The terminal access request response message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, wireless configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information; wherein, The preamble sequence number information is used to indicate the first preamble, and the first temporary terminal identifier is the same as a temporary identifier allocated by the first network device to the terminal or is a temporary identifier reassigned by the second network device to the terminal.

31. The method of claim 27, wherein, The second message comprises at least one of the following parameters: location information of the terminal, preset network device information, or service type information.

32. The method of claim 24, wherein, The third message is one of the following: an RRC connection establishment message, an RRC connection reestablishment message, a handover command message, or a redirection command message.

33. The method of claim 24, wherein, The orbital height of the first network device is different from the orbital height of the second network device.

34. A communications device, characterized by The terminal resides in a first network device, and the apparatus comprises: a sending module configured to send a second message to the first network device, wherein the second message is one of the following: an RRC connection establishment request message and an RRC reestablishment request message; a receiving module configured to receive a third message from the first network device, wherein the third message comprises an estimated time advance of a second network device; The sending module is further configured to send a first preamble to the second network device at a first sending time in advance of the estimated time advance of the second network device, so that the second network device determines timing offset information according to an actual receiving time window of the first preamble, wherein the timing offset information is used to indicate a time offset between the actual receiving time window of the first preamble and a preset receiving time window of the first preamble. The sending module is further configured to send a first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble at a second sending time in advance of the estimated time advance, wherein the second sending time is separated from the first sending time by a first preset time on the PUSCH, the coverage range of the first network device is different from the coverage range of the second network device, and the first message is one of the following: a radio resource control (RRC) connection establishment complete message and an RRC reestablishment complete message.

35. A communications device, characterized by The second network device, and the apparatus comprises: receive a terminal access request message from a first network device, wherein the terminal access request message is generated by the first network device after receiving a second message sent by a terminal; the second message is one of an RRC connection setup request message and an RRC reestablishment request message; send a terminal access request response message to the first network device, wherein the terminal access request response message comprises an estimated time advance of the second network device; and receive a first preamble from the terminal, wherein the terminal is camped on the first network device, the first preamble is sent at a first sending time in advance of the estimated time advance of the second network device, and the coverage range of the first network device is different from that of the second network device; determine timing offset information according to an actual receiving time window of the first preamble, wherein the timing offset information is used to indicate a time offset between the actual receiving time window of the first preamble and a preset receiving time window of the first preamble; receive a first message on a physical uplink shared channel (PUSCH) corresponding to the first preamble according to the timing offset information, wherein the first message is sent at a second sending time in advance of the estimated time advance, the second sending time is separated from the first sending time by a first preset time, and the first message is at least one of an RRC connection setup complete message and an RRC reestablishment complete message.

36. A communications device, characterized by The apparatus is applied to a first network device and comprises: receive a second message from a terminal, wherein the second message is one of an RRC connection setup request message and an RRC reestablishment request message; send a terminal access request message to a second network device; receive a terminal access request response message from the second network device; and send a terminal access request message to a second network device; The sending module is further configured to send a third message to the terminal, so that the terminal sends a first preamble to the second network device at a first sending time in advance of an estimated time advance of the second network device according to the third message, so that the second network device determines timing offset information according to an actual receiving time window of the first preamble, wherein the timing offset information is used to indicate a time offset between the actual receiving time window of the first preamble and a preset receiving time window of the first preamble, sends a first message to the second network device on a physical uplink shared channel (PUSCH) corresponding to the first preamble at a second sending time in advance of the estimated time advance, wherein the second sending time is separated from the first sending time by a first preset time, and the third message comprises information used by the terminal to determine the estimated time advance of the second network device, and the information used by the terminal to determine the estimated time advance of the second network device comprises at least one of the estimated time advance of the second network device or ephemeris information of the second network device; the terminal is located in the first network device; and the first message is at least one of an RRC connection setup complete message and an RRC reestablishment complete message. The third message further comprises at least one of the following parameters: a first temporary terminal identifier of the terminal, radio configuration information configured by the second network device for the terminal, frequency point information of the second network device, PUSCH configuration information for transmitting the first message, subcarrier spacing information of the second network device, or preamble sequence number information; wherein The preamble sequence number information is used to indicate the first preamble, the first temporary terminal identifier is the same as a temporary identifier allocated to the terminal by the first network device or is a temporary identifier reallocated to the terminal by the second network device; and a coverage range of the first network device is different from a coverage range of the second network device.

37. A terminal, characterized by Comprising: a processor, and a memory connected to the processor in communication; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method of any one of claims 1-16.

38. A second network device, comprising: Comprising: a processor, and a memory connected to the processor in communication; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method of any one of claims 17-23.

39. A first network device, comprising: Comprising: a processor, and a memory connected to the processor in communication; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method of any one of claims 24-33.

40. A computer-readable storage medium, comprising: The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are configured to implement the method of any one of claims 1-33.

41. A computer program product, characterised in that, The computer program is executed by a processor to implement the method of any one of claims 1-33.

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