A method for accessing a network, a terminal and a network device

Abstract

The present invention provides a method for accessing a network, a terminal and a network device. The method on the terminal side comprises: before the terminal sends a first message to a target network device according to a two-step random access process, obtaining a time advance compensation amount for sending the first message; and sending the first message to the target network device according to the time advance compensation amount. The solution of the present invention can realize low-overhead and fast network access for a user terminal.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a method for accessing a network, a terminal and a network device. Background Art

[0002] In a wireless communication system, a user needs to determine the random access type before initiating a random access to a base station to ensure the efficiency and reliability of information access. The random access types include: four-step random access and two-step random access.

[0003] In the traditional handover process, if the target cell or target network device does not configure dedicated access resources for the terminal, the terminal needs to re-initiate the four-step random access process on the target cell;

[0004] Although four-step random access can ensure the reliability of user access to the network, the access efficiency is not high because two information exchanges are required between the user and the base station. In comparison, when the round-trip time (RTT) of information transmission is relatively small, there is no need for timing advance, and the channel quality is relatively good, which is conducive to the demodulation of the physical uplink shared channel (PUSCH). The user will choose the type of random access used for the first time according to a reference signal receiving power (RSRP) threshold configured in the base station system message. For example, when the RSRP is greater than the threshold value, two-step random access will be selected. Therefore, this basically limits the two-step random access to the situation where the user is close to the base station. For scenarios with relatively large RTT, such as satellite communication systems, even low-orbit satellites have an orbital altitude of generally 300 to 1500 km. In this case, if the base station and the user can reduce the two information exchanges, the access delay can be reduced by half, thereby greatly improving the user experience. However, for satellite communications, the RTT transmission delay will be as high as 2 to 10 ms, which is much larger than the time range that can be compensated by the cyclic prefix. At this time, the timing advance adjustment mechanism must be considered to ensure that the PUSCH in MsgB can be correctly demodulated.

[0005] In addition, for satellite communication systems, especially non-geosynchronous satellites, although the satellite orbit altitude is lower than that of synchronous satellites, due to the high speed of the satellite, the ground users can only see the satellite for a few minutes to more than ten minutes. In order to ensure the continuity of business services, users need to frequently switch beams within or between satellites. However, how to enable low-overhead and fast access to the network for user terminals is a difficult problem. Summary of the invention

[0006] The technical problem to be solved by the present invention is how to provide a method, terminal and network equipment for accessing a network, which can enable a user terminal to quickly access the network with low overhead.

[0007] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0008] A method for accessing a network, applied to a terminal, the method comprising:

[0009] Before the terminal sends a first message to the target network device according to the two-step random access process, obtaining a time advance compensation amount for sending the first message;

[0010] The first message is sent to the target network device according to the time advance compensation amount.

[0011] Optionally, obtaining a time advance compensation amount for sending the first message includes:

[0012] Acquire a time advance determined by information interaction between the terminal and the source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device;

[0013] According to the timing advance determined by information interaction between the terminal and the source network device and the timing advance difference, a timing advance compensation amount for sending the first message is acquired.

[0014] Optionally, obtaining a time advance determined by information interaction between the terminal and the source network device includes:

[0015] The terminal interacts with the source network device through a four-step random access process to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, and the terminal-specific time advance is the time advance determined by the terminal according to its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

[0016] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0017] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA;

[0018] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, and Delta_TA is the difference value of the time advance amount of the source network device and the target network device relative to the terminal.

[0019] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0020] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset;

[0021] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, Delta_TA is the time advance difference between the source network device and the target network device relative to the terminal, and N_TA_offset is a configuration value.

[0022] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0023] By formula:

[0024] TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset+Rate_TA, obtaining the time advance compensation amount for sending the first message;

[0025] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal-specific time advance amount, Delta_TA is the difference in the time advance amount of the source network device and the target network device relative to the terminal, N_TA_offset is a configuration value; Rate_TA is determined according to the mobility information of the terminal or the target network device.

[0026] Optionally, the source network device and the target network device are both satellites, and the Delta_TA is determined based on at least one of the spatial positions, operating altitudes, and operating speeds of the source network device and the target network device and the location information of the terminal.

[0027] An embodiment of the present invention further provides a method for accessing a network, which is applied to a target network device, and the method includes:

[0028] Before receiving a first message sent by a terminal to a target network device according to a two-step random access process, obtaining a time advance compensation amount for sending the first message;

[0029] The first message sent by the receiving terminal is received according to the time advance compensation amount.

[0030] Optionally, obtaining a time advance compensation amount for sending the first message includes:

[0031] Acquire a time advance determined by information interaction between the terminal and the source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device;

[0032] According to the timing advance determined by information interaction between the terminal and the source network device and the timing advance difference, a timing advance compensation amount for sending the first message is acquired.

[0033] Optionally, before obtaining the time advance compensation amount for sending the first message, the method further includes:

[0034] Interact with the source network device to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, where the terminal-specific time advance is the time advance determined by the terminal based on its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

[0035] An embodiment of the present invention further provides a device for accessing a network, characterized in that it is applied to a terminal, and the device includes:

[0036] A processing module, configured to obtain a time advance compensation amount for sending the first message before the terminal sends the first message to the target network device according to the two-step random access process;

[0037] A transceiver module is used to send the first message to the target network device according to the time advance compensation amount.

[0038] An embodiment of the present invention further provides a terminal, including:

[0039] The processor is configured to obtain a time advance compensation amount for sending the first message before the terminal sends the first message to the target network device according to the two-step random access process;

[0040] A transceiver is used to send the first message to the target network device according to the time advance compensation amount.

[0041] An embodiment of the present invention further provides a device for accessing a network, which is applied to a target network device, and the device includes:

[0042] A processing module, configured to obtain a time advance compensation amount for sending a first message before a first message is sent by a receiving terminal to a target network device according to a two-step random access process;

[0043] The transceiver module is used to receive the first message sent by the terminal according to the time advance compensation amount.

[0044] An embodiment of the present invention further provides a network device, including:

[0045] A processor, configured to obtain a time advance compensation amount for sending a first message before receiving a first message sent by a terminal to a target network device according to a two-step random access process;

[0046] The transceiver is used to receive the first message sent by the terminal according to the time advance compensation amount.

[0047] An embodiment of the present invention further provides a communication device, comprising: a processor and a memory storing a computer program, wherein when the computer program is executed by the processor, the method described above is executed.

[0048] An embodiment of the present invention further provides a computer-readable storage medium storing instructions, which, when executed on a computer, enable the computer to execute the method described above.

[0049] The above solution of the present invention includes at least the following beneficial effects:

[0050] In the solution of the present invention, before the user terminal sends the first message to the target network device according to the two-step random access process, it obtains the time advance compensation amount for sending the first message; and sends the first message to the target network device according to the time advance compensation amount. As a result, the user terminal uses the two-step random access mechanism when accessing the target network device during switching, completes TA compensation before sending the first message (MsgA), ensures that the MsgA of the two-step access can be correctly demodulated, and effectively reduces the delay, signaling overhead and user power consumption in the random access process when the terminal switches. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a flowchart of a method for accessing a network on a terminal side according to an embodiment of the present invention;

[0052] Figure 2is a schematic diagram of a four-step random access process according to an embodiment of the present invention;

[0053] Figure 3 is a schematic diagram of a two-step random access process according to an embodiment of the present invention;

[0054] Figure 4 This is a specific implementation process of the method for implementing TA compensation on the terminal side according to an embodiment of the present invention;

[0055] Figure 5 This is a specific implementation process of the method for implementing TA compensation on the network side according to an embodiment of the present invention;

[0056] Figure 6 is a flowchart of a method for accessing a network on the network side according to an embodiment of the present invention;

[0057] Figure 7 This is a schematic diagram of a specific implementation process of an embodiment of the present invention using a satellite as a network device;

[0058] Figure 8 It is a module block diagram of a network access device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0060] like Figure 1 As shown, an embodiment of the present invention provides a method for accessing a network, which is applied to a terminal, and the method includes:

[0061] Step 11, before the terminal sends a first message to the target network device according to the two-step random access process, obtaining a time advance compensation amount for sending the first message;

[0062] Step 12: Send the first message to the target network device according to the time advance compensation amount.

[0063] In this embodiment, before the user terminal sends the first message to the target network device according to the two-step random access process, it obtains the time advance compensation amount for sending the first message; and sends the first message to the target network device according to the time advance compensation amount. Thus, when the user switches to access a new network device, the two-step random access mechanism is used, and TA compensation is completed before sending the first message (MsgA), ensuring that the MsgA of the two-step access can be correctly demodulated, effectively reducing the delay, signaling overhead and user power consumption in the random access process when the terminal switches.

[0064] In an optional embodiment of the present invention, in step 11: obtaining a time advance compensation amount for sending the first message includes:

[0065] Step 111, obtaining a timing advance determined by information interaction between the terminal and the source network device and a timing advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected to the terminal before the terminal accesses the target network device;

[0066] Here, the terminal interacts with the source network device through a four-step random access process to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, and the terminal-specific time advance is the time advance determined by the terminal based on its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

[0067] Step 112: Acquire a timing advance compensation amount for sending the first message according to the timing advance determined by information interaction between the terminal and the source network device and the timing advance difference.

[0068] like Figure 2 As shown, in this embodiment, when the terminal initially accesses the network, it uses a traditional contention-based four-step random access process to access the source network device; the process of information interaction between the terminal and the source network device may include a four-step random access process, which specifically includes the following steps:

[0069] The terminal sends an uplink signal including a preamble on the PRACH (Physical Random Access Channel) resource, which is called Msg1.

[0070] The terminal receives a random access response (RAR) sent by the base station, called Msg2, which contains the timing advanced compensation amount TA (Timing advanced) information;

[0071] The terminal sends uplink data on the uplink time-frequency resources indicated by the RAR, which is called Msg3. When sending uplink data, the TA is used for time synchronization adjustment.

[0072] The terminal receives downlink data sent by the base station side, and the downlink data includes contention resolution related information, which is called Msg4.

[0073] In this process, uplink time synchronization is achieved between the terminal and the source network device (such as source base station 1), and source base station 1 obtains the TA information compensated by the terminal, that is, the time advance determined by the information interaction between the terminal and the source network device. Among them, the TA information includes a cell / beam unified TA (Common_TA, that is, the above-mentioned first time advance) and a terminal-specific TA (Specific_TA, that is, the above-mentioned second time advance); the common TA is broadcast by the network side and is consistent for all terminals in the cell, and the terminal-specific TA is the TA obtained by each terminal from the network side through the TA indication in the MAC RAR (media access layer access request response, that is, the above-mentioned indication information) or calculated by the terminal based on its own positioning information and satellite ephemeris information;

[0074] Source base station 1 performs measurement configuration on the terminal, and the measurement results of the terminal are used to assist source base station 1 in making a handover decision. The terminal performs measurement reporting according to the base station configuration results, and source base station 1 makes a handover decision based on the terminal measurement reporting results and the handover algorithm; when handover is required, the terminal accesses the target network device according to the two-step random access process.

[0075] like Figure 3 As shown, the two-step random access process includes: the terminal sends a first message (MsgA) to the target network device, and the terminal accesses a response message (MsgB) of the first message fed back by the target network device; the two-step random access sends Msg1 and Msg3 in the original four-step random access in one step, called MsgA; Msg2 and Msg4 are further merged into MsgB.

[0076] In an optional embodiment of the present invention, step 112 may include:

[0077] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA;

[0078] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, and Delta_TA is the difference value of the time advance amount of the source network device and the target network device relative to the terminal.

[0079] In an optional embodiment of the present invention, step 112 may include:

[0080] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset;

[0081] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, Delta_TA is the time advance difference between the source network device and the target network device relative to the terminal, and N_TA_offset is a configuration value.

[0082] In an optional embodiment of the present invention, step 112 may include: obtaining a time advance compensation amount for sending the first message through a formula TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset+Rate_TA;

[0083] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal-specific time advance amount, Delta_TA is the difference in the time advance amount of the source network device and the target network device relative to the terminal, N_TA_offset is a configuration value; Rate_TA is determined according to the mobility information of the terminal or the target network device.

[0084] Here, in the above embodiment, the source network device and the target network device are both satellites, and the Delta_TA is determined based on at least one of the spatial position, operating altitude, and operating speed of the source network device and the target network device and the location information of the terminal.

[0085] In the above embodiment, Delta_TA can be interacted by the source network device and the target network device, and after being determined according to the relevant information of the source network device, the target network device and the terminal, the source network device indicates it to the terminal, for example, it can be indicated to the terminal through an RRC reconfiguration message.

[0086] In an optional embodiment of the present invention, the method for accessing a network may further include:

[0087] Configuration information sent by the source network device is received, where the configuration information is used to indicate the target network device to be accessed by the terminal and / or to indicate that the terminal accesses the target network device according to a two-step random access process.

[0088] Here, the configuration information may include first configuration information and / or second configuration information. The first configuration information may be RRC (radio resource control) reconfiguration information, indicating to the terminal the target network device to be accessed by the terminal. The second configuration information may also be RRC configuration information, indicating to the terminal that the terminal uses a two-step random access process to access the target network device. Of course, the first configuration information and the second configuration information may also be implemented by one configuration information, such as RRC reconfiguration information.

[0089] The above step 112 may be implemented on the terminal side or on the network side, or may be implemented on both the terminal side and the network side.

[0090] When implemented on the terminal side, Figure 4 As shown, the specific process includes:

[0091] The source base station 1 instructs the terminal to compensate the time advance compensation amount TA when sending MsgA;

[0092] The source base station 1 obtains the ephemeris information of the target base station 2 through the intersatellite link, obtains the spatial position (such as longitude and latitude), operating altitude, operating speed and other information of the target base station 2, and calculates the first differential value TA Delta_TA1 of the TA between the target base station 2 and the terminal relative to the TA between the source base station 1 and the terminal based on this information, combined with the spatial position information (such as longitude and latitude), operating altitude, operating speed and other information of the original base station 1, as well as the terminal position information;

[0093] Source base station 1 adds Delta_TA1 information to the RRC reconfiguration information and indicates it to the terminal;

[0094] The terminal initiates a two-step random access process to the target base station 2. The terminal completes the compensation of the timing advance when sending MsgA to the target base station 2:

[0095] TA1=Common_TA+Specific_TA+Delta_TA1+N_TA_offset;

[0096] N_TA_offset is a value configured by high-level signaling. If not configured, it is a system default value.

[0097] Optionally, step 6) and step 7) are performed in any order, and indication information of the two-step random access process can be added to the RRC reconfiguration information.

[0098] When implemented on the network side, Figure 5 As shown, the target base station 2 completes TA pre-compensation on the network side before receiving MsgA:

[0099] The source base station 1 sends a first synchronization message required for initial access of the terminal to the target base station 2 via an intersatellite link. The first synchronization message at least includes first TA information; wherein the first TA information is Common_TA and / or UE Specific_TA for the terminal to access the source base station 1;

[0100] The target base station 2 obtains the ephemeris information of the source base station 1 through the intersatellite link, and obtains the spatial position (such as longitude and latitude), operating altitude and operating speed of the source base station 1, and calculates the second differential value TA Delta_TA2 between the TA of the target base station 2 and the terminal relative to the TA of the source base station 1 and the terminal based on this information and the terminal position information;

[0101] When the target base station 2 receives the MsgA sent by the detection terminal, the terminal side does not perform TA compensation when sending MsgA, and completes TA pre-compensation on the network side of the target base station 2. The pre-compensated TA amount is: TA2 = Common_TA + Specific_TA + Delta_TA2 + N_TA_offset;

[0102] Optionally, considering satellite mobility, whether it is terminal-side compensation TA1 or network-side pre-compensation TA2, a Rate_TA can be superimposed. Rate_TA is used to compensate for the time variation caused by satellite or terminal mobility. This value can be calculated based on mobility information.

[0103] In an optional embodiment of the present invention, the network side and the terminal side of the target base station 2 each compensate a part of the TA; for example: the base station side compensates Common TA+Specific_TA, and the terminal side compensates Delta_TA1 or Delta TA2.

[0104] In a specific implementation example, Figure 6 As shown in the figure, the source network device and the target network device are both satellites for explanation:

[0105] The terminal needs to perform frequency offset pre-compensation when sending MsgA, or perform frequency offset post-compensation when receiving MsgA at target base station 2.

[0106] In particular, if the terminal is switching between different cells within the same satellite, there is no need to exchange information between satellites. The specific process includes:

[0107] 1. The base station sends RRC reconfiguration information to the terminal, and instructs the terminal to access the target cell 2 using a two-step random access method through the configuration information;

[0108] 2. The terminal uses a two-step random access method to send MsgA to the target cell 2. Its TA compensation is performed in two cases:

[0109] Example 1: Source cell 1 instructs the terminal to perform additional TA compensation

[0110] The base station calculates the distance between the target cell 2 and the terminal according to the ephemeris information and the user location information, and calculates the first difference value TA Delta_TA1 between the TA of the target cell 2 and the terminal relative to the TA of the source cell 1 and the terminal; the source cell 1 adds Delta_TA1 information to the RRC reconfiguration information and indicates it to the terminal;

[0111] The terminal needs to complete the timing advance compensation when sending MsgA:

[0112] TA1=Common_TA+Specific_TA+Delta_TA1+N_TA_offset;

[0113] Example 2: Target cell 2 completes TA pre-compensation before receiving MsgA

[0114] The base station calculates the distance between the target cell 2 and the terminal according to the ephemeris information and the user location information, and calculates the second differential TA Delta_TA2 between the TA between the target cell 2 and the terminal relative to the TA between the source cell 1 and the terminal;

[0115] The target cell 2 completes the TA pre-compensation when receiving the MsgA sent by the detection terminal. The compensated TA amount is: TA2 = Common_TA + Specific_TA + Delta_TA2 + N_TA_offset;

[0116] In the above-mentioned embodiment of the present invention, a two-step access mechanism is used when a user accesses a new cell during switching. In order to ensure that MsgA of the two-step access can be correctly demodulated, TA compensation needs to be completed on the terminal side or the network side. This can meet the needs of users in the air-ground integrated system to quickly access the network, thereby effectively reducing the delay, signaling overhead and user power consumption in the random access process during terminal switching.

[0117] like Figure 7 As shown, an embodiment of the present invention further provides a method for accessing a network, which is applied to a target network device, and the method includes:

[0118] Step 71, before receiving a first message sent by a terminal to a target network device according to a two-step random access process, obtaining a time advance compensation amount for sending the first message;

[0119] Step 72: Receive the first message sent by the terminal according to the time advance compensation amount.

[0120] Optionally, obtaining a time advance compensation amount for sending the first message includes:

[0121] Acquire a time advance determined by information interaction between the terminal and the source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device;

[0122] According to the timing advance determined by information interaction between the terminal and the source network device and the timing advance difference, a timing advance compensation amount for sending the first message is acquired.

[0123] Optionally, before obtaining the time advance compensation amount for sending the first message, the method further includes:

[0124] Interact with the source network device to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, where the terminal-specific time advance is the time advance determined by the terminal based on its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

[0125] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0126] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA;

[0127] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, and Delta_TA is the difference value of the time advance amount of the source network device and the target network device relative to the terminal.

[0128] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0129] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset;

[0130] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, Delta_TA is the time advance difference between the source network device and the target network device relative to the terminal, and N_TA_offset is a configuration value.

[0131] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0132] By formula:

[0133] TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset+Rate_TA, obtaining the time advance compensation amount for sending the first message;

[0134] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal-specific time advance amount, Delta_TA is the difference in the time advance amount of the source network device and the target network device relative to the terminal, N_TA_offset is a configuration value; Rate_TA is determined according to the mobility information of the terminal or the target network device.

[0135] Optionally, the source network device and the target network device are both satellites, and the Delta_TA is determined based on at least one of the spatial positions, operating altitudes, and operating speeds of the source network device and the target network device and the location information of the terminal.

[0136] It should be noted that the method described in this embodiment is a network side method corresponding to the above-mentioned terminal side method. All implementation methods in the above-mentioned method embodiments are applicable to the network side embodiments and can achieve the same technical effects.

[0137] like Figure 8 As shown, an embodiment of the present invention further provides a device 80 for accessing a network, which is applied to a terminal, and the device 80 includes:

[0138] A processing module 81 is configured to obtain a time advance compensation amount for sending a first message before the terminal sends the first message to the target network device according to a two-step random access process;

[0139] The transceiver module 82 is used to send the first message to the target network device according to the time advance compensation amount.

[0140] Optionally, obtaining a time advance compensation amount for sending the first message includes:

[0141] Acquire a time advance determined by information interaction between the terminal and the source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device;

[0142] According to the timing advance determined by information interaction between the terminal and the source network device and the timing advance difference, a timing advance compensation amount for sending the first message is acquired.

[0143] Optionally, obtaining a time advance determined by information interaction between the terminal and the source network device includes:

[0144] The terminal interacts with the source network device through a four-step random access process to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, and the terminal-specific time advance is the time advance determined by the terminal according to its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

[0145] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0146] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA;

[0147] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, and Delta_TA is the difference value of the time advance amount of the source network device and the target network device relative to the terminal.

[0148] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0149] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset;

[0150] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, Delta_TA is the time advance difference between the source network device and the target network device relative to the terminal, and N_TA_offset is a configuration value.

[0151] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0152] By formula:

[0153] TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset+Rate_TA, obtaining the time advance compensation amount for sending the first message;

[0154] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal-specific time advance amount, Delta_TA is the difference in the time advance amount of the source network device and the target network device relative to the terminal, N_TA_offset is a configuration value; Rate_TA is determined according to the mobility information of the terminal or the target network device.

[0155] Optionally, the source network device and the target network device are both satellites, and the Delta_TA is determined based on at least one of the spatial positions, operating altitudes, and operating speeds of the source network device and the target network device and the location information of the terminal.

[0156] It should be noted that the device is a device corresponding to the above method, and all implementation methods in the above method embodiments are applicable to the embodiments of the device and can achieve the same technical effects.

[0157] An embodiment of the present invention further provides a terminal, including:

[0158] The processor is configured to obtain a time advance compensation amount for sending the first message before the terminal sends the first message to the target network device according to the two-step random access process;

[0159] A transceiver is used to send the first message to the target network device according to the time advance compensation amount.

[0160] Optionally, obtaining a time advance compensation amount for sending the first message includes:

[0161] Acquire a time advance determined by information interaction between the terminal and the source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device;

[0162] According to the timing advance determined by information interaction between the terminal and the source network device and the timing advance difference, a timing advance compensation amount for sending the first message is acquired.

[0163] Optionally, obtaining the time advance determined by information interaction between the terminal and the source network device includes: the terminal interacts with the source network device through a four-step random access process to obtain a first time advance and / or a second time advance, the first time advance is the time advance broadcast by the source network device, the second time advance is the terminal-specific time advance, the terminal-specific time advance is the time advance determined by the terminal according to its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

[0164] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0165] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA;

[0166] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, and Delta_TA is the difference value of the time advance amount of the source network device and the target network device relative to the terminal.

[0167] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0168] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset;

[0169] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, Delta_TA is the time advance difference between the source network device and the target network device relative to the terminal, and N_TA_offset is a configuration value.

[0170] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0171] By formula:

[0172] TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset+Rate_TA, obtaining the time advance compensation amount for sending the first message;

[0173] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal-specific time advance amount, Delta_TA is the difference in the time advance amount of the source network device and the target network device relative to the terminal, N_TA_offset is a configuration value; Rate_TA is determined according to the mobility information of the terminal or the target network device.

[0174] Optionally, the source network device and the target network device are both satellites, and the Delta_TA is determined based on at least one of the spatial positions, operating altitudes, and operating speeds of the source network device and the target network device and the location information of the terminal.

[0175] It should be noted that the device is a terminal corresponding to the above method, and all implementation methods in the above method embodiments are applicable to the embodiments of the terminal and can achieve the same technical effects.

[0176] An embodiment of the present invention further provides a device for accessing a network, which is applied to a target network device, and the device includes:

[0177] A processing module, configured to obtain a time advance compensation amount for sending a first message before a first message is sent by a receiving terminal to a target network device according to a two-step random access process;

[0178] The transceiver module is used to receive the first message sent by the terminal according to the time advance compensation amount.

[0179] Optionally, obtaining a time advance compensation amount for sending the first message includes:

[0180] Acquire a time advance determined by information interaction between the terminal and the source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device;

[0181] According to the timing advance determined by information interaction between the terminal and the source network device and the timing advance difference, a timing advance compensation amount for sending the first message is acquired.

[0182] Optionally, before obtaining the time advance compensation amount for sending the first message, the method further includes:

[0183] Interact with the source network device to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, where the terminal-specific time advance is the time advance determined by the terminal based on its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

[0184] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0185] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA;

[0186] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, and Delta_TA is the difference value of the time advance amount of the source network device and the target network device relative to the terminal.

[0187] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0188] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset;

[0189] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, Delta_TA is the time advance difference between the source network device and the target network device relative to the terminal, and N_TA_offset is a configuration value.

[0190] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0191] By formula:

[0192] TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset+Rate_TA, obtaining the time advance compensation amount for sending the first message;

[0193] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal-specific time advance amount, Delta_TA is the difference in the time advance amount of the source network device and the target network device relative to the terminal, N_TA_offset is a configuration value; Rate_TA is determined according to the mobility information of the terminal or the target network device.

[0194] Optionally, the source network device and the target network device are both satellites, and the Delta_TA is determined based on at least one of the spatial positions, operating altitudes, and operating speeds of the source network device and the target network device and the location information of the terminal.

[0195] It should be noted that the device is a device corresponding to the above method, and all implementation methods in the above method embodiments are applicable to the embodiments of the device and can achieve the same technical effects.

[0196] An embodiment of the present invention further provides a network device, including:

[0197] A processor, configured to obtain a time advance compensation amount for sending a first message before receiving a first message sent by a terminal to a target network device according to a two-step random access process;

[0198] The transceiver is used to receive the first message sent by the terminal according to the time advance compensation amount.

[0199] Optionally, obtaining a time advance compensation amount for sending the first message includes:

[0200] Acquire a time advance determined by information interaction between the terminal and the source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device;

[0201] According to the timing advance determined by information interaction between the terminal and the source network device and the timing advance difference, a timing advance compensation amount for sending the first message is acquired.

[0202] Optionally, before obtaining the time advance compensation amount for sending the first message, the method further includes:

[0203] Interact with the source network device to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, where the terminal-specific time advance is the time advance determined by the terminal based on its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

[0204] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0205] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA;

[0206] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, and Delta_TA is the difference value of the time advance amount of the source network device and the target network device relative to the terminal.

[0207] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0208] Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset;

[0209] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, Delta_TA is the time advance difference between the source network device and the target network device relative to the terminal, and N_TA_offset is a configuration value.

[0210] Optionally, acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device includes:

[0211] By formula:

[0212] TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset+Rate_TA, obtaining the time advance compensation amount for sending the first message;

[0213] Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal-specific time advance amount, Delta_TA is the difference in the time advance amount of the source network device and the target network device relative to the terminal, N_TA_offset is a configuration value; Rate_TA is determined according to the mobility information of the terminal or the target network device.

[0214] Optionally, the source network device and the target network device are both satellites, and the Delta_TA is determined based on at least one of the spatial positions, operating altitudes, and operating speeds of the source network device and the target network device and the location information of the terminal.

[0215] It should be noted that the device is a network device corresponding to the above method, and all implementation methods in the above method embodiment are applicable to the embodiment of the network device and can achieve the same technical effect.

[0216] The embodiment of the present invention further provides a communication device, comprising: a processor, a memory storing a computer program, wherein when the computer program is executed by the processor, the method described above is executed. All implementations in the above method embodiment are applicable to the embodiment of the network device, and can also achieve the same technical effect.

[0217] The embodiment of the present invention also provides a computer-readable storage medium storing instructions, which, when executed on a computer, enable the computer to execute the method described above. All implementations in the above method embodiment are applicable to the embodiment of the network device and can achieve the same technical effect.

[0218] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0219] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0220] In the embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0221] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0222] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0223] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical disks.

[0224] In addition, it should be noted that in the apparatus and method of the present invention, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. Moreover, the steps of performing the above-mentioned series of processing can naturally be performed in chronological order according to the order of description, but it is not necessary to perform them in chronological order, and some steps can be performed in parallel or independently of each other. For those of ordinary skill in the art, it is understood that all or any steps or components of the method and apparatus of the present invention can be implemented in any computing device (including processors, storage media, etc.) or a network of computing devices in hardware, firmware, software or a combination thereof, which can be achieved by those of ordinary skill in the art using their basic programming skills after reading the description of the present invention.

[0225] Therefore, the purpose of the present invention can also be achieved by running a program or a group of programs on any computing device. The computing device can be a well-known general device. Therefore, the purpose of the present invention can also be achieved by simply providing a program product containing a program code that implements the method or device. That is to say, such a program product also constitutes the present invention, and the storage medium storing such a program product also constitutes the present invention. Obviously, the storage medium can be any well-known storage medium or any storage medium developed in the future. It should also be pointed out that in the device and method of the present invention, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. In addition, the steps of performing the above-mentioned series of processing can naturally be performed in chronological order according to the order of description, but it is not necessary to perform them in chronological order. Some steps can be performed in parallel or independently of each other.

[0226] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for accessing a network, characterized in that: Applied to a terminal, the method comprises: Before the terminal sends a first message to the target network device according to the two-step random access process, obtaining a time advance compensation amount for sending the first message; Sending the first message to the target network device according to the time advance compensation amount; Acquiring a time advance compensation amount for sending the first message includes: Acquire a time advance determined by information interaction between the terminal and a source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device; Acquire a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device; Acquiring a time advance determined by information interaction between the terminal and the source network device, including: The terminal interacts with the source network device through a four-step random access process to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, and the terminal-specific time advance is the time advance determined by the terminal according to its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

2. The method for accessing a network according to claim 1, characterized in that: Acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device, including: Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA; Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, and Delta_TA is the difference value of the time advance amount of the source network device and the target network device relative to the terminal.

3. The method for accessing a network according to claim 1, characterized in that: Acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device, including: Obtain the time advance compensation amount for sending the first message through the formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset; Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal specific time advance amount, Delta_TA is the time advance difference between the source network device and the target network device relative to the terminal, and N_TA_offset is a configuration value.

4. The method for accessing a network according to claim 1, characterized in that: Acquiring a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device, including: By formula: TA=Common_TA+Specific_TA+Delta_TA+N_TA_offset+Rate_TA, obtaining the time advance compensation amount for sending the first message; Among them, TA is the time advance compensation amount, Common_TA is the time advance amount broadcast by the source network device, Specific_TA is the terminal-specific time advance amount, Delta_TA is the difference in the time advance amount of the source network device and the target network device relative to the terminal, N_TA_offset is a configuration value; Rate_TA is determined according to the mobility information of the terminal or the target network device.

5. The method for accessing a network according to any one of claims 2 to 4, characterized in that: The source network device and the target network device are both satellites, and the Delta_TA is determined based on at least one of the spatial positions, operating altitudes, and operating speeds of the source network device and the target network device and the location information of the terminal.

6. A method for accessing a network, characterized in that: Applied to a target network device, the method comprises: Before receiving a first message sent by a terminal to a target network device according to a two-step random access process, obtaining a time advance compensation amount for sending the first message; receiving, according to the time advance compensation amount, the first message sent by the terminal; Acquiring a time advance compensation amount for sending the first message includes: Acquire a time advance determined by information interaction between the terminal and a source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device; Acquire a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device; Before obtaining the time advance compensation amount for sending the first message, the method further includes: Interact with the source network device to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, where the terminal-specific time advance is the time advance determined by the terminal based on its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

7. A device for accessing a network, characterized in that: Applied to a terminal, the device comprises: A processing module, configured to obtain a time advance compensation amount for sending the first message before the terminal sends the first message to the target network device according to the two-step random access process; A transceiver module, configured to send the first message to the target network device according to the time advance compensation amount; Acquiring a time advance compensation amount for sending the first message includes: Acquire a time advance determined by information interaction between the terminal and a source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device; Acquire a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device; Acquiring a time advance determined by information interaction between the terminal and the source network device, including: The terminal interacts with the source network device through a four-step random access process to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, and the terminal-specific time advance is the time advance determined by the terminal according to its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

8. A terminal, characterized in that: include: The processor is configured to obtain a time advance compensation amount for sending the first message before the terminal sends the first message to the target network device according to the two-step random access process; a transceiver, configured to send the first message to the target network device according to the time advance compensation amount; Acquiring a time advance compensation amount for sending the first message includes: Acquire a time advance determined by information interaction between the terminal and a source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device; Acquire a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device; Acquiring a time advance determined by information interaction between the terminal and the source network device, including: The terminal interacts with the source network device through a four-step random access process to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, and the terminal-specific time advance is the time advance determined by the terminal according to its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

9. A device for accessing a network, characterized in that: Applied to a target network device, the device comprises: A processing module, configured to obtain a time advance compensation amount for sending a first message before a first message is sent by a receiving terminal to a target network device according to a two-step random access process; A transceiver module, configured to receive the first message sent by the terminal according to the time advance compensation amount; Acquiring a time advance compensation amount for sending the first message includes: Acquire a time advance determined by information interaction between the terminal and a source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device; Acquire a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device; Before obtaining the time advance compensation amount for sending the first message, the method further includes: Interact with the source network device to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, where the terminal-specific time advance is the time advance determined by the terminal based on its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

10. A network device, characterized in that: include: A processor, configured to obtain a time advance compensation amount for sending a first message before receiving a first message sent by a terminal to a target network device according to a two-step random access process; a transceiver, configured to receive the first message sent by the terminal according to the time advance compensation amount; Acquiring a time advance compensation amount for sending the first message includes: Acquire a time advance determined by information interaction between the terminal and a source network device and a time advance difference between the source network device and the target network device relative to the terminal, wherein the source network device is a network device connected by the terminal before the terminal accesses the target network device; Acquire a time advance compensation amount for sending the first message according to a time advance amount and a time advance amount difference determined by information interaction between the terminal and the source network device; Before obtaining the time advance compensation amount for sending the first message, the method further includes: Interact with the source network device to obtain a first time advance and / or a second time advance, where the first time advance is the time advance broadcast by the source network device, and the second time advance is the terminal-specific time advance, where the terminal-specific time advance is the time advance determined by the terminal based on its own positioning information and satellite ephemeris information, or the time advance indicated to the terminal by the network side through indication information.

11. A communication device, characterized in that: include: A processor and a memory storing a computer program, wherein when the computer program is executed by the processor, the method according to any one of claims 1 to 5 or the method according to any one of claim 6 is executed.

12. A computer-readable storage medium, characterized in that: Instructions are stored, and when the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 5 or the method according to any one of claim 6.

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