Communication method, apparatus and system

Abstract

The present application is applied to the technical field of communications. Provided are a communication method, apparatus and system. In the communication method provided in the present application, when GNSS information of a terminal device fails, a network side is promptly triggered to adjust a timing advance for the terminal device. The communication method comprises: when it is determined that GNSS information of a terminal device has failed, the terminal device sending a first message to an access network device on the basis of GNSS information prior to failure; and the terminal device receiving first indication information from the access network device, wherein the first indication information is used for indicating a first parameter, and the first parameter is used for determining a timing advance for the next time the terminal device sends uplink data.

Description

Communication method, apparatus and system

[0001] The present application claims priority to the Chinese patent application No. 202410423982.9, filed on April 9, 2024, and entitled "Communication method, apparatus and system", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a communication method, apparatus and system. BACKGROUND

[0003] In order to provide better communication services for users, non-terrestrial network (NTN) is considered to be introduced into the existing communication system. In the network architecture based on NTN, satellites can be used as network-side devices to provide services for terminal devices.

[0004] For data transmission, the communication system requires uplink synchronization. In the ground network, in order to realize uplink synchronization, the base station can calculate the timing advance (TA) for each terminal device accessing the base station in the random access (RA) process and send it to the terminal device. The TA can be understood as the propagation delay between the terminal device and the base station. If the terminal device sends data in advance by TA time, it can ensure that the data reaches the base station at the start time of the subframe. Therefore, the terminal device can determine the time of sending uplink data based on the acquired TA.

[0005] The NTN network also requires uplink synchronization. In the NTN network, the terminal device needs to calculate the TA based on its global navigation satellite system (GNSS) position and related parameters sent by the network side to the terminal device. After receiving the uplink data of the terminal device, the network side can determine whether to send indication information for correcting the TA to the terminal device based on the arrival time of the data. The indication information includes the corrected value of the related parameters used to calculate the TA. The terminal device can calculate a new TA based on the corrected value of the related parameters.

[0006] However, in the case that the GNSS position of the terminal device deviates too much from the real position, the arrival time of the uplink data at the network side deviates too much, and the correction amount required for the related parameters for correcting the TA is relatively large, because the indication information for correcting the TA is limited by the number of bits, the maximum value that can be represented is limited, and the network side is limited by the number of transmission bits. Even if the value of the related parameters is corrected, uplink synchronization cannot be achieved. SUMMARY

[0007] Embodiments of the present application provide a communication method, device and system, which can trigger the network side to adjust the time advance for the terminal device in time when the GNSS information of the terminal device is invalid.

[0008] To achieve the above object, embodiments of the present application adopt the following technical solutions:

[0009] In a first aspect, a communication method is provided, which can be executed by a terminal device or a module (such as a processor, a chip or a chip system, etc.) applied to the terminal device. Hereinafter, the terminal device is taken as an example to illustrate the communication method, which comprises: in a case where it is determined that the GNSS information of the terminal device is invalid, the terminal device sends a first message to an access network device based on the GNSS information before the invalidation. The terminal device receives first indication information from the access network device, and the first indication information is used to indicate a first parameter, which is used to determine the time advance of the terminal device for sending uplink data next time.

[0010] Based on the communication method provided by the embodiments of the present application, when the GNSS information of the terminal device is invalid, the terminal device can be triggered to send an uplink message to the network side based on the GNSS information before the invalidation, so that the network side can adjust the TA in time based on the uplink message when the GNSS information is invalid, thereby avoiding the uplink out-of-sync problem caused by long time without adjusting the TA. Moreover, since the terminal device sends the uplink message based on the GNSS information before the invalidation, when the invalid GNSS information deviates too much from the real position, the network side cannot adjust the TA through the indication information due to the limitation of the maximum TA value that can be adjusted by the network side based on the bit number of the indication information.

[0011] In combination with the first aspect described above, in a possible design, after receiving the first indication information from the access network device, the method further comprises: the terminal device starts a first timer. In a case where it is determined that the GNSS information of the terminal device is still invalid during the running of the first timer, after the running of the first timer is timed out, the terminal device sends the first message to the access network device again based on the first indication information.

[0012] Based on the present solution, if the GNSS information is still invalid, the terminal device can send the first message again to trigger the access network device to adjust the TA again, so that the uplink synchronization can be maintained.

[0013] In combination with the first aspect described above, in a possible design, the first timer is configured to the terminal device by the access network device; or the first timer is pre-configured by the terminal device.

[0014] With reference to the first aspect, in a possible design of the method, the method further includes: receiving, by the terminal device, second indication information from the access network device, where the second indication information is used to indicate the terminal device to periodically send the first message according to the first timer.

[0015] Based on this scheme, the access network device can instruct the terminal device to periodically send the uplink message to trigger adjustment of the TA when the GNSS information is invalid, which is beneficial to network management of the terminal device.

[0016] With reference to the first aspect, in a possible design of the method, in a case where it is determined that the GNSS information of the terminal device is still invalid during running of the first timer, the first message is sent to the access network device again after the first timer ends, including: in a case where it is determined that the GNSS information of the terminal device is still invalid during running of the first timer, and the number of times of sending the first message has not exceeded a first threshold, the first message is sent to the access network device again after the first timer ends; or in a case where it is determined that the GNSS information of the terminal device is still invalid during running of the first timer, and a time length of the invalid GNSS information has not exceeded a second threshold, the first message is sent to the access network device again after the first timer ends.

[0017] Based on this scheme, the mechanism of sending the first message by the terminal device based on the timer is limited by the maximum number of times or the maximum time length, which avoids the terminal device from endlessly sending the first message to the access network device, and causes resource waste.

[0018] With reference to the first aspect, in a possible design of the method, the first threshold or the second threshold is configured to the terminal device by the access network device; or the first threshold or the second threshold is preconfigured by the terminal device.

[0019] With reference to the first aspect, in a possible design of the method, the method further includes: receiving, by the terminal device, third indication information from the access network device, where the third indication information is used to instruct sending of the first message in a case where the GNSS information is invalid.

[0020] Based on this scheme, the access network device can instruct the terminal device to send the first message in a case where the GNSS information is invalid, to trigger adjustment of the TA, which is beneficial to enhancement of network management of the terminal device.

[0021] With reference to the first aspect, in a possible design of the method, in a case where it is determined that the GNSS information of the terminal device is invalid, the terminal device sends the first message to the access network device, including: in a case where it is determined that the GNSS information of the terminal device is invalid, the terminal device starts a second timer. In a case where the terminal device does not receive the first indication information from the access network device during running of the second timer, the terminal device sends the first message to the access network device after the second timer runs out.

[0022] Based on the scheme, after determining that the GNSS information is invalid, the terminal device can first wait for a period of time, and if the network side has not corrected the TA during the waiting, the terminal device triggers to send the first message, which is beneficial to reduce the signaling overhead.

[0023] In a possible design in combination with the first aspect, the second timer is configured by the access network device to the terminal device, or the second timer is pre-configured by the terminal device.

[0024] In a possible design in combination with the first aspect, in a case where it is determined that the GNSS information of the terminal device is invalid, the terminal device sends the first message to the access network device, including: in a case where the terminal device receives downlink data from the access network device and determines that the GNSS information of the terminal device is invalid, the terminal device sends the first message to the access network device.

[0025] After receiving the downlink data, the terminal device can need to feed back a response message to the access network device according to a feedback mechanism. Based on this, in a case where the GNSS information is invalid, the terminal device can send the first message to the access network device to trigger adjustment of the TA, so as to avoid that, when the terminal device feeds back the response message subsequently, the access network device cannot receive the response message due to incorrect TA.

[0026] In a possible design in combination with the first aspect, in a case where it is determined that the GNSS information of the terminal device is invalid, the method further includes: the terminal device stops a third timer; the third timer is used to determine whether the time advance currently used by the terminal device is available.

[0027] Since, after the GNSS information is invalid, the terminal device will execute the communication method provided in the embodiments to trigger adjustment of the TA, at this time, it is not necessary to use the third timer to determine whether the current TA is available, and timely stopping the third timer is beneficial to reduce the processing overhead.

[0028] In a possible design in combination with the first aspect, the first message is carried in a sounding reference signal (SRS), a physical uplink control channel (PUCCH) message, a medium access control layer control element (MAC CE), a radio resource control (RRC) message, or a random access preamble.

[0029] The present application provides a plurality of forms of the first message, and the terminal device can send different first messages based on actual needs.

[0030] In a possible design in combination with the first aspect, the first message includes fourth indication information, and the fourth indication information is used to indicate that the GNSS information of the terminal device is invalid; or the first message is used to indicate that the GNSS information of the terminal device is invalid.

[0031] Based on the scheme, the terminal device can indicate the access network device that the GNSS information of the terminal device is invalid, so as to avoid the network side from considering that the TA of the terminal device does not need to be corrected.

[0032] In a possible design of the first aspect, the first indication information is carried in a MAC CE, or the first indication information is carried in a random access response (RAR) message in a random access procedure.

[0033] In a possible design of the first aspect, before the terminal device receives the first indication information from the access network device, the method further includes: the terminal device receives fifth indication information from the access network device, where the fifth indication information is used to indicate that a random access is initiated. The terminal device sends a random access request to the access network device according to the fifth indication information. In this case, the access network device sends the first indication information to the terminal device through a RAR in a random access procedure.

[0034] Based on the scheme, the TA can be corrected through a random access procedure, and the maximum value that can be corrected by the RAR is larger than that by a MAC CE.

[0035] In a possible design of the first aspect, the terminal device sends a first message to the access network device based on the GNSS information before the invalidation, and the first message includes:

[0036] The terminal device calculates a time advance based on the GNSS information before the invalidation.

[0037] The terminal device sends the first message to the access network device, where a sending time of the first message is determined according to the time advance.

[0038] Based on the scheme, since the terminal device sends an uplink message based on the GNSS information before the invalidation, when the invalid GNSS information deviates from the real position too much, the network side cannot adjust the TA through the indication information due to the limitation of the maximum TA value that can be adjusted by the bit number of the indication information.

[0039] The second aspect provides a communication apparatus for implementing the method implemented by the terminal device in the first aspect.

[0040] The communication apparatus includes modules, units, or means corresponding to the above method, which can be implemented by hardware, software, or by executing corresponding software by hardware. The hardware or software includes one or more modules or units corresponding to the above functions.

[0041] With reference to the above second aspect, in a possible design of the communication apparatus, the processing module is further configured to start a first timer, and determine whether the GNSS information is invalid during running of the first timer. The transceiver is further configured to, in a case where the GNSS information is still invalid during running of the first timer, send, after expiration of the first timer, the first message to the access network device again based on the first indication information.

[0042] With reference to the above second aspect, in a possible design of the communication apparatus, the processing module is further configured to start a first timer, and determine whether the GNSS information is invalid during running of the first timer. The transceiver is further configured to, in a case where the GNSS information is still invalid during running of the first timer, send, after expiration of the first timer, the first message to the access network device again based on the first indication information.

[0043] With reference to the above second aspect, in a possible design of the communication apparatus, the first timer is configured to the communication apparatus by the access network device, or the first timer is preconfigured to the communication apparatus.

[0044] With reference to the above second aspect, in a possible design of the communication apparatus, the transceiver is further configured to receive second indication information from the access network device, where the second indication information is used to indicate that the communication apparatus periodically sends the first message according to the first timer.

[0045] With reference to the above second aspect, in a possible design of the communication apparatus, the transceiver sends, in a case where the GNSS information is still invalid during running of the first timer, the first message to the access network device again after expiration of the first timer, including: in a case where the GNSS information is still invalid during running of the first timer and a number of times of sending the first message does not exceed a first threshold, sending, after expiration of the first timer, the first message to the access network device again; or in a case where the GNSS information is still invalid during running of the first timer and a time length of the GNSS information being invalid does not exceed a second threshold, sending, after expiration of the first timer, the first message to the access network device again.

[0046] With reference to the above second aspect, in a possible design of the communication apparatus, the first threshold or the second threshold is configured to the communication apparatus by the access network device, or the first threshold or the second threshold is preconfigured to the communication apparatus.

[0047] With reference to the above second aspect, in a possible design of the communication apparatus, the transceiver is further configured to receive third indication information from the access network device, where the third indication information is used to indicate sending the first message in a case where the GNSS information is invalid.

[0048] With reference to the second aspect above, in a possible design of the second aspect, the transceiver is configured to send the first message to the access network device in the case that the GNSS information is invalid, including that the processor is further configured to start a second timer in the case that the GNSS information is invalid. In the case that the communication apparatus does not receive the first indication information from the access network device during running of the second timer, the transceiver is configured to send the first message to the access network device after the second timer expires.

[0049] With reference to the second aspect above, in a possible design of the second aspect, the second timer is configured to the communication apparatus by the access network device, or the second timer is pre-configured to the communication apparatus.

[0050] With reference to the second aspect above, in a possible design of the second aspect, the transceiver is configured to send the first message to the access network device in the case that the GNSS information is invalid, including that the transceiver is configured to send the first message to the access network device in the case that the transceiver receives downlink data from the access network device and the processor determines that the GNSS information of the terminal device is invalid.

[0051] With reference to the second aspect above, in a possible design of the second aspect, the processor is further configured to stop a third timer, and the third timer is configured to determine whether a time advance currently used by the communication apparatus is available.

[0052] With reference to the second aspect above, in a possible design of the second aspect, the first message is carried in a sounding reference signal (SRS), a physical uplink control channel (PUCCH) message, a medium access control (MAC) control element (CE), a radio resource control (RRC) message, or a random access preamble.

[0053] With reference to the second aspect above, in a possible design of the second aspect, the first message includes fourth indication information, and the fourth indication information is configured to indicate that the GNSS information of the terminal device is invalid, or the first message is configured to indicate that the GNSS information of the terminal device is invalid.

[0054] With reference to the second aspect above, in a possible design of the second aspect, the first indication information is carried in a MAC CE, or the first indication information is carried in a random access response (RAR) message in a random access procedure.

[0055] With reference to the second aspect above, in a possible design of the second aspect, the transceiver is further configured to receive fifth indication information from the access network device, and the fifth indication information is configured to indicate initiation of a random access. The transceiver is further configured to send a random access request to the access network device according to the fifth indication information.

[0056] With reference to the second aspect above, in a possible design, the sending, by the transceiver module, of the first message to the access network device based on the GNSS information before the failure includes: calculating, by the processing module, a time advance based on the GNSS information before the failure; and sending, by the transceiver module, the first message to the access network device; and the sending time of the first message is determined according to the time advance.

[0057] In a third aspect, a communication apparatus is provided, which includes a processor configured to execute instructions stored in a memory, and when the processor executes the instructions, the communication apparatus performs the method in any of the aspects above. The communication apparatus can be the terminal device in the first aspect or any of the possible designs of the first aspect, or a module (for example, a chip) applied to the terminal device.

[0058] In a possible design, the communication apparatus further includes the memory configured to store the computer instructions. Optionally, the processor and the memory are integrated together, or the processor and the memory are separately arranged.

[0059] In a possible design, the memory is coupled with the processor and is outside the communication apparatus.

[0060] In a fourth aspect, a communication apparatus is provided, which includes a processor and an interface circuit configured to communicate with a module outside the communication apparatus; and the processor is configured to perform the method in any of the aspects above by means of a logic circuit, or by running a computer program or instructions. The communication apparatus can be the terminal device in the first aspect or any of the possible designs of the first aspect, or a module (for example, a chip) applied to the terminal device.

[0061] Alternatively, the interface circuit can be a code / data reading / writing interface circuit, which is configured to receive computer execution instructions (the computer execution instructions are stored in the memory, and can be directly read from the memory or can pass through other devices) and transmit the computer execution instructions to the processor, so that the processor runs the computer execution instructions to perform the method in any of the aspects above.

[0062] In a possible design, the communication apparatus further includes the memory configured to store the computer program or instructions. Optionally, the processor and the memory are integrated together, or the processor and the memory are separately arranged.

[0063] In a possible design, the memory is coupled with the processor and is outside the communication apparatus.

[0064] In some possible designs, the communication apparatus can be a chip or a chip system.

[0065] In a fifth aspect, the present application provides a computer readable storage medium, which stores instructions. When the instructions are executed on a computer, the computer can perform the method executed by the terminal device in the first aspect or any possible design of the first aspect.

[0066] In a sixth aspect, the present application provides a computer program product containing instructions. When the instructions are executed on a computer, the computer can perform the method executed by the terminal device in the first aspect or any possible design of the first aspect.

[0067] In a seventh aspect, a communication apparatus (for example, the communication apparatus can be a chip or a chip system) is provided, which includes a processor configured to implement the functions involved in any of the aspects. In a possible design, the communication apparatus further includes a memory configured to store necessary program instructions and data. When the communication apparatus is a chip system, the communication apparatus can be composed of a chip or can include a chip and other discrete devices.

[0068] In an eighth aspect, a communication system is provided, which includes a terminal device and an access network device. The terminal device is configured to implement the method in the first aspect or any possible design of the first aspect.

[0069] The technical effects brought by any of the designs of the second aspect to the eighth aspect can be referred to the technical effects brought by the different designs of the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0070] FIG. 1 is a schematic diagram of an architecture of an NTN network;

[0071] FIG. 2 is a schematic diagram of a TA in an NTN network;

[0072] FIG. 3 is a schematic diagram of an architecture of a communication system according to an embodiment of the present application;

[0073] FIG. 4 is a schematic diagram of an O-RAN architecture according to an embodiment of the present application;

[0074] FIG. 5 is a schematic diagram of an interaction of a communication method according to an embodiment of the present application;

[0075] FIG. 6 is a schematic diagram of a flow according to an embodiment of the present application;

[0076] FIG. 7 is a schematic diagram of an interaction of an O-RAN architecture according to an embodiment of the present application;

[0077] FIG. 8 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application;

[0078] FIG. 9 is a structural schematic diagram of another communication apparatus provided by an embodiment of the present application. DETAILED DESCRIPTION

[0079] To facilitate understanding of the technical solutions of the embodiments of the present application, first, a brief introduction of the related art of the present application is given as follows.

[0080] 1. NTN network

[0081] The NTN network has the advantages of wide coverage, long communication distance, high reliability, great flexibility, high throughput, etc. Introducing non-terrestrial communication into the existing communication system can provide communication services for areas that are difficult to cover by ground networks, such as oceans, forests, etc., enhance the reliability of communication, and also provide more data transmission resources to support a larger number of connections.

[0082] For the network side device in the air in the NTN network, this paper takes a satellite as an example, and in actual application, it can also include unmanned aerial vehicles and other devices.

[0083] Currently, various radio access network (RAN) architectures based on NTN have been proposed, which can be applied to the 5th generation (5G) mobile communication system or new radio (NR) system. The following will be introduced in combination with (1), (2), (3) and (4) in FIG. 1.

[0084] Architecture 1 is shown in (1) of FIG. 1, also known as architecture with transparent satellite. In architecture 1, the base station on the ground communicates with the terminal device through the Uu interface, the NTN gateway on the ground is connected with the ground base station through a wired connection, and the satellite communicates with the NTN gateway on the ground through wireless signals. Among them, the role of the satellite is: radio frequency filtering, frequency conversion and amplification, that is, the satellite mainly acts as an L1 relay, responsible for regenerating physical layer signals, and does not have other higher protocol layers. In architecture 1, the satellite can also be understood as a remote radio unit (RRU) of the ground base station.

[0085] Architecture 2 is shown in (2) of FIG. 1. In architecture 2, the satellite is a regenerative satellite without inter-satellite link (ISL) and has the processing function of a base station. That is, in this architecture, the satellite also acts as a base station. In architecture 2, the satellite can exchange routing information (SRI) with the NTN gateway on the ground through the NG interface (NG over SRI). The satellite can communicate with the core network (CN) through the NG interface. The satellite can communicate with the terminal device through the Uu interface.

[0086] Architecture 3 is shown in (3) of FIG. 1. In architecture 3, the satellite is a regenerative satellite with an inter-satellite link and has the processing function of a base station. That is, in this architecture, the satellite also acts as a base station. In architecture 3, different satellites can communicate through the inter-satellite link, and an Xn interface can be established between the satellites. When the satellite is not visible to the NTN gateway on the ground, the satellite can use other satellites to return data to the ground. The satellite can exchange routing information with the NTN gateway through the NG interface. The satellite can communicate with the core network through the NG interface. The satellite can communicate with the terminal device through the Uu interface.

[0087] Architecture 4 is shown in (4) of FIG. 1. In architecture 4, the satellite is a regenerative satellite with the processing function of a distributed unit (DU) in a base station. That is, in this architecture, the satellite acts as a DU. The satellite can exchange routing information with the NTN gateway through the F1 interface (F1 over SRI). The satellite can communicate with the centralized unit (CU) of the base station on the ground through the NTN gateway. The CU can communicate with the core network through the NG interface. The satellite can communicate with the terminal device through the Uu interface.

[0088] Architecture 5 is not shown in (1), (2), (3), and (4) of FIG. 1. In architecture 5, the satellite is a base station with integrated access and backhual (IAB) function. Architecture 5 is similar to architecture 4, but the difference is that in architecture 5, a mobile terminal (MT) module is also deployed on the satellite in addition to the DU, and the satellite can use the MT to perform backhaul with the air interface of the ground base station.

[0089] Optionally, as shown in (1), (2), (3), and (4) of FIG. 1, the core network can be connected to the data network through the N6 interface.

[0090] 2. Uplink synchronization:

[0091] Currently, the mobile communication system requires uplink synchronization. Uplink synchronization refers to that the time when uplink data sent by all terminal devices reaches the base station needs to be strictly aligned, so that the base station can successfully receive the uplink data sent by the terminal device.

[0092] The following introduces the process of implementing uplink synchronization in a ground network. The terminal device performs a random access process and sends a preamble (which can be referred to as a random access preamble) to the base station at the start time of a subframe, which can also be referred to as message 1 (Msg1). At this time, the terminal device has not yet synchronized uplink. The base station calculates the propagation delay between the terminal device and the base station according to the time when the Msg1 is received and the start time of the subframe, which can also be referred to as TA. The meaning is that if the terminal device sends data TA in advance, it can ensure that the data reaches the base station at the start time of the subframe. The base station sends the TA to the terminal device through message 2 (message 1, Msg2), which can also be referred to as a random access response (RAR). After that, when the terminal device performs uplink transmission, it will determine the transmission time according to this TA information, so that the data sent by the terminal device can reach the base station at the start time of the subframe. At this point, the uplink synchronization has been completed. It can be understood that different terminal devices can have different TAs.

[0093] The NTN network also requires uplink synchronization. The following introduces the process of implementing uplink synchronization in a ground network.

[0094] In the NTN network, due to the long propagation distance from the terminal device to the satellite to the gateway station, it is not possible to follow the above synchronization mechanism, and the NTN network side broadcasts a TA value, leaving the propagation delay to be compensated by the terminal device. In the NTN, the TA adopts a segmented compensation mechanism, as shown in FIG. 2, the concept of reference point is introduced in the NTN, the reference point represents a virtual position, the propagation delay from the reference point to the gateway station is compensated by the base station, which is referred to as Kmac, and the terminal device only needs to compensate the propagation delay from the terminal device to the satellite to the reference point, which is referred to as T TA . That is, in the NTN network, T TA is the TA used by the terminal device to determine the transmission time of the uplink data, which is the TA that the terminal device needs to obtain.

[0095] Currently, the formula for calculating T TA is:

[0096] Where T c is the length of a time slot. For the TA of the satellite-to-reference point part, it can be understood as a constant broadcasted by the network side to the terminal device. TA ,N TA,offset , The three represent the TA of the terminal device-to-satellite part, which is mainly compensated by , is calculated by the terminal device based on its own GNSS position and the ephemeris information of the satellite (used to represent the position of the satellite), wherein the ephemeris information is broadcasted by the network side to the terminal device, and the GNSS position of the terminal device is obtained by the terminal device itself (for example, the terminal device can obtain its own position through Beidou / GPS);N TA is a small amount of compensation considering that there may be multipath effects in the signal propagation between the terminal device and the satellite, and directly calculating the relative distance based on the position may have some errors, so N TA is used for compensation, TA is sent by the network side to the terminal device in the random access process. TA,offset represents the transceiver switching time of the base station, which is broadcasted by the network side to the terminal device.

[0097] After the terminal device obtains each parameter in the above formula (1), it calculates T TA based on the above formula (1), and determines the time of sending uplink data by itself based on T TA .

[0098] The above segmented compensation mechanism is for transparent satellites, i.e. transparent satellite architecture. For regenerative satellites in NTN networks, the TA does not need to introduce a reference point, and the TA between the satellite and the terminal device is the final TA that the terminal device needs to obtain, so Kmac and are not needed.

[0099] The above introduces the method for obtaining the initial TA in the ground network and the NTN network. Since the terminal device will move, the TA also needs to be continuously adjusted based on the relative position of the terminal device and the base station. If there is uplink transmission between the terminal device and the network, the network side will determine whether to send a media access control (MAC) control element (CE) to adjust (or correct, adjustment and correction are the same concept in this paper) the TA based on the arrival time of the uplink data of the terminal device.

[0100] In the terrestrial network, the TA Command MAC CE directly indicates the adjustment value of TA, while in the NTN network, the TA Command MAC CE indicates the adjustment value of N TA This adjustment value is used to adjust the TA. Among them, the TA Command MAC CE indicates the adjustment value based on the last TA or N TA TA or N TA The absolute value of TA.

[0101] For adjusting TA through the TA Command MAC CE, the terminal device side will maintain a time synchronization timer (TAT). After the terminal device obtains the initial TA, the TAT is started. The terminal device considers that within the time of the TAT, the uplink synchronization can be ensured. When the terminal device receives the TA Command, the TAT is reset. If the terminal device does not receive the TA Command until the TAT expires (for example, the terminal device always does not send uplink data to the network side), the terminal device considers that the uplink is out of synchronization at this time. When the terminal device has uplink data, the terminal device needs to perform random access first and reacquire uplink synchronization.

[0102] Based on the above introduction, it can be seen that in the current uplink synchronization mechanism, the network side adjusts the TA based on the uplink data sent by the terminal device. However, in the NTN network, if the terminal device has no uplink data transmission demand for a long time, the network side cannot adjust the TA in time. When there is an uplink data transmission demand next time, if the GNSS position of the terminal device deviates from the real position too much, the terminal device calculates the TA based on the GNSS position and sends the uplink data based on the TA, which will cause the time offset of the uplink data reaching the base station to be too much. The TA Command is limited by the number of bits, and the adjustment value that can be indicated is limited. The network side cannot correct it, thereby causing the uplink to be out of synchronization.

[0103] Based on this problem, the embodiments of the present application provide a communication method, device and system. When the GNSS information of the terminal device is invalid, the terminal device can send an uplink message to the network side, so that the network side can adjust the TA in time based on the uplink message, thereby avoiding the problem of uplink out of synchronization caused by long-time non-adjustment of TA.

[0104] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In the description of the present application, unless otherwise specified, “ / ” represents a “or” relationship between the objects before and after the “ / ”, for example, A / B can represent A or B; “and / or” in the present application is only a description of the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, in the description of the present application, unless otherwise specified, “multiple” means two or more than two. “At least one of the following” or the like means any combination of the items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple. In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, “first”, “second”, and the like are used to distinguish the same items or similar items with basically the same function and effect. Those skilled in the art can understand that “first”, “second”, and the like do not limit the quantity and execution order, and “first”, “second”, and the like do not necessarily mean different. At the same time, in the embodiments of the present application, “exemplary” or “for example” means to serve as an example, illustration or description. Any embodiment or design scheme described as “exemplary” or “for example” in the embodiments of the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, “exemplary” or “for example” is used to present the relevant concept in a specific manner, for understanding.

[0105] In the embodiments of the present application, “indication” can include direct indication and indirect indication, and can also include explicit indication and implicit indication. The information indicated by a certain information (such as the first indication information below) is referred to as to-be-indicated information, and there are many ways to indicate the to-be-indicated information in the specific implementation process, for example but not limited to, the to-be-indicated information can be directly indicated, such as the to-be-indicated information itself or the 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, and the other part of the to-be-indicated information is known or agreed in advance. For example, the indication of a specific information can also be achieved by means of the arrangement order of each information agreed in advance (for example, specified by a protocol), thereby reducing the indication overhead to a certain extent. At the same time, the common part of each information can be identified and uniformly indicated, so as to reduce the indication overhead caused by separately indicating the same information.

[0106] In addition, the specific indication manner can also be various existing indication manners, for example but not limited to the indication manners described above and various combinations thereof. The specific details of various indication manners can refer to the prior art, and will not be described herein. As can be seen from the above, for example, when multiple pieces of information of the same type need to be indicated, the indication manners of different information can be different. In the specific implementation process, the required indication manner can be selected according to the specific needs, and the selected indication manner is not limited by the embodiments of the application. In this way, the indication manners involved in the embodiments of the application should be understood as covering various methods that can enable the to-be-indicated party to know the to-be-indicated information.

[0107] It should be understood that the to-be-indicated information can be sent as a whole or divided into multiple sub-information and sent separately, and the sending period and / or sending occasion of the sub-information can be the same or different. The specific sending method is not limited by the embodiments of the application. The sending period and / or sending occasion of the sub-information can be predefined, for example, predefined according to a protocol, or configured by the sending end device by sending configuration information to the receiving end device.

[0108] In the embodiments of the application, "sending information to (for example, a terminal device) can be understood as that the destination of the information is the terminal device. It can include directly or indirectly sending information to the terminal device. "Receiving information from (for example, a terminal device)" or "receiving information from (for example, a terminal device)" can be understood as that the source of the information is the terminal device, and it can include directly or indirectly receiving information from the terminal device. The information can be processed as necessary between the source and the destination of the information, for example, format change, etc., but the destination can understand the valid information from the source. Similar expressions in the application can be understood similarly, and will not be described herein.

[0109] In the embodiments of the application, "predefined", "predefined", "preconfigured" or "preconfigured" can be implemented by pre-storing corresponding codes, tables or other methods that can be used to indicate related information in the device, for example, can be burned in the device when the device is manufactured, and the specific implementation manner is not limited by the embodiments of the application. Wherein, "saving" can mean saving in one or more memories. The one or more memories can be separately set or integrated in the encoder or decoder, processor or communication device. The one or more memories can be part of the separately set and part of the integrated in the decoder, processor or communication device. The type of memory can be any form of storage medium, and the embodiments of the application do not limit this.

[0110] The "protocol" referred to in the embodiments of the present application can refer to a protocol family in the communication field, a standard protocol similar to the protocol family frame structure, or a related protocol applied to a future communication system, and the embodiments of the present application do not make specific limitations thereto.

[0111] In the embodiments of the present application, "when", "in the case of", "if", and the like all refer to the device making corresponding processing under certain objective conditions, and are not limited to time, and do not require the device to have a judgment action when implemented, nor does it mean that there are other limitations.

[0112] The technical solutions provided by the present application can be applied to various communication systems, for example, can be applied to a 3rd Generation Partnership Project (3GPP) communication system, such as a 4th generation (4G) mobile communication system, a long term evolution (LTE) system, a 5G mobile communication system and an evolved system thereof, an NTN system, a vehicle to everything (V2X) system, a system of LTE and new radio (NR) hybrid networking, or a device-to-device (D2D) system, a machine to machine (M2M) communication system, an internet of things (IoT), a wireless fidelity (WiFi) system, and other next-generation communication systems, such as a 6th generation (6G) mobile communication system, etc. In addition, the term "system" can be replaced by "network".

[0113] It should be noted that the network architecture and service scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of network architecture and the appearance of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0114] FIG. 3 is a possible, non-limiting communication system to which the embodiments of the present application are applicable. As shown in FIG. 3, the communication system includes a RAN 100, which includes at least one access network device 110 and at least one terminal device 120. The terminal device 120 can communicate with the access network device 110 in a wireless manner.

[0115] With any access network device 110 and any terminal device 120 shown in FIG. 3 as an example, in the communication method provided by the embodiments of the application, the terminal device 120 can send a first message to the access network device 110 based on the GNSS information before the GNSS information is determined to be invalid in the case that the GNSS information of the terminal device 120 is determined to be invalid. After receiving the first message, the access network device 110 sends first indication information to the terminal device 120, and the first indication information is used to indicate the first parameter. After receiving the first indication information, the terminal device 120 determines the time advance of the next uplink data transmission according to the first parameter. The specific implementation and technical effects of the scheme will be described in detail in the subsequent method embodiments, and will not be described here.

[0116] Optionally, other devices such as wireless relay devices, wireless backhaul devices, gateway stations (not shown in FIG. 3), etc. can also be included in the RAN 100.

[0117] Optionally, the communication system 10 can also include a CN 200. The access network device 110 can be connected to the CN 200 in a wireless or wired manner. The core network device in the CN 200 and the access network device 110 in the RAN 100 can be different physical devices respectively, or can be the same physical device integrated with the core network logic function and the wireless access network logic function.

[0118] The RAN 100 can be a 3GPP related cellular system, such as an LTE system, a 5G system, or a future-oriented evolution system (e.g., a 6G mobile communication system). The RAN 100 can also be an NTN network, an open access network (open RAN, O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. The RAN 100 can also be a communication system in which two or more of the above systems are integrated. In addition, the term "system" can be replaced by "network".

[0119] Optionally, if the RAN 100 is an NTN network, the architecture of the RAN 100 can refer to the introduction of the RAN architecture based on the NTN network above. The access network device 110 can be a base station in the RAN architecture based on the NTN network, and the terminal device 120 can be a terminal device in the RAN architecture based on the NTN network. Among them, in the scenario where the satellite works in the transparent mode, for example, in the architecture 1 shown in (1) of FIG. 1, the access network device 110 can be deployed on the ground. In the scenario where the satellite works in the regenerative mode, for example, in the architectures 2-4 shown in (2), (3) and (4) of FIG. 1, and in the architecture 5, the access network device 110 can be deployed on the satellite, or in other words, the satellite is the access network device 110 at this time, for realizing the function of the access network device in the embodiments of the present application.

[0120] The access network device 110 in the embodiments of the present application refers to a RAN node (or device) for accessing a terminal to a wireless network. In a possible scenario, the access network device can also be referred to as a base station, for realizing the function of the base station. For example, the access network device can be a gNB (the next generation node B), a TRP (transmission reception point), an eNB (evolved Node B), an RNC (radio network controller), a NB (Node B), a BSC (base station controller), a BTS (base transceiver station), a home eNB (home evolved Node B, or home Node B, HNB), a BBU (base band unit), or a Wifi AP (access point), etc.

[0121] In another possible scenario, a terminal device accesses a wireless network through cooperation of a plurality of network devices, and each of the network devices implements part of functions of a base station. For example, the network device can include a centralized unit (CU) node, or a distributed unit (DU) node, or a RAN device including a CU node and a DU node. The RAN device including the CU node and the DU node splits protocol layers of a gNB in the NR system, and part of protocol layers are placed in the CU for centralized control, and the rest or all protocol layers are distributed in the DU and controlled by the CU. Further, the centralized unit CU can be further divided into a control plane (CU-CP) and a user plane (CU-UP). Among them, the CU-CP is responsible for the control plane function, mainly including the radio resource control (RRC) and the control plane corresponding packet data convergence protocol (PDCP), i.e., PDCP-C. The PDCP-C is mainly responsible for encryption and decryption of control plane data, integrity protection, data transmission, etc. The CU-UP is responsible for the user plane function, mainly including the service data adaptation protocol (SDAP) and the user plane corresponding PDCP, i.e., PDCP-U. Among them, the SDAP is mainly responsible for processing data of the core network and mapping the quality of service (QoS) flow to the bearer. The PDCP-U is mainly responsible for encryption and decryption of the data plane, integrity protection, header compression, sequence number maintenance, data transmission, etc. The CU-CP and the CU-UP are connected through an E1 interface. The CU-CP represents the gNB and is connected to the core network through an NG interface. The control plane of the CU, i.e., F1-C, is connected to the DU through an F1 interface. The CU-UP is connected to the DU through the user plane of the F1 interface, i.e., F1-U. Of course, there is also a possible implementation that the PDCP-C is also in the CU-UP.

[0122] In different systems, the CU (or CU-CP and CU-UP), DU or RU can also have different names, but those skilled in the art can understand their meanings. For example, in the O-RAN system, the CU can also be referred to as O-CU (open CU), the DU can also be referred to as O-DU, the CU-CP can also be referred to as O-CU-CP, the CU-UP can also be referred to as O-CU-UP, and the RU can also be referred to as O-RU. For the convenience of description, the CU, CU-CP, CU-UP, DU and RU are taken as examples for description in this application. Any one of the CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0123] Figure 4 is a possible, non-limiting architecture of O-RAN provided by embodiments of the present application. In the architecture, the RAN intelligent controller (RIC) is used to collect network information and perform necessary optimization tasks, which communicates with gNB-CU and gNB-DU through E2 interface, i.e., O-RIC can directly control gNB-DU or control gNB-DU through gNB-CU. The gNB-CU is the CU node of gNB supporting O-RAN function. The gNB-DU is the DU node of gNB supporting O-RAN function. The gNB-CU and gNB-DU can communicate through F1 interface.

[0124] Optionally, the gNB-DU can be a DU node in IAB, i.e., IAB-DU.

[0125] If the O-RAN architecture shown in Figure 4 is combined with the communication system shown in Figure 3, the gNB-CU or gNB-DU can establish a communication connection with the terminal device 120, and the RIC can control the gNB-CU or gNB-DU to send relevant information to the terminal device 120 through the E2 interface. That is, the functions of the access network device in embodiments of the present application can be jointly implemented by the gNB-CU or gNB-DU and the RIC.

[0126] Among them, if the architecture shown in Figure 4 is located in the NTN network, under the transparent satellite architecture, the CU and DU can be located on the ground, and the RIC can also be located on the ground. Under the regenerative satellite architecture, the CU and DU can be deployed on the satellite, and the RIC is not limited to be on the ground or on the satellite.

[0127] All or part of the functions of the access network device in the present application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (such as a cloud platform). The access network device in the present application can also be a logical node, a logical module or software that can implement all or part of the functions of the access network device.

[0128] The terminal device in the embodiments of the present application can also be referred to as a terminal, a user equipment (UE), a mobile station (MS), a mobile terminal, etc., and refers to a device that provides voice and / or data connectivity for a user, such as a handheld device having wireless connection functions, a vehicle-mounted device, etc. The terminal device can be widely applied to various scenarios, such as V2X communication, machine-type communication (MTC), IoT, virtual reality (VR), augmented reality (AR), industrial control, self driving, remote medical surgery, smart grid, smart home, smart office, smart bracelet, smart city, etc. At present, some examples of terminal devices are: a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, etc. The embodiments of the present application do not limit the device form of the terminal device.

[0129] The core network device in the embodiments of the present application refers to a device in the core network that provides service support for the terminal device. At present, some examples of core network devices are: an access and mobility management function (AMF) entity, a session management function (SMF) entity, a user plane function (UPF) entity, etc., which are not listed one by one here. Among them, the AMF entity can be responsible for access management and mobility management of the terminal; the SMF entity can be responsible for session management, such as session establishment of a user, etc.; the UPF entity can be a functional entity of the user plane, mainly responsible for connecting external networks.

[0130] In the embodiments of the present application, an entity can also be referred to as a network element or a functional entity, for example, the AMF entity can also be referred to as an AMF network element or an AMF functional entity, and for example, the SMF entity can also be referred to as an SMF network element or an SMF functional entity, etc.

[0131] The communication method provided by the embodiments of the present application will be described below taking the interaction between the access network device 110 and the terminal device 120 shown in FIG. 3 as an example.

[0132] It should be noted that the names of messages between various network elements in the following embodiments of the present application or the names of various parameters in the messages are only examples, and other names can also be used in specific implementations, and the embodiments of the present application do not limit this.

[0133] As shown in FIG. 5, a communication method provided by the embodiments of the present application is shown. In FIG. 5, the access network device and the terminal device are taken as an example to show the execution subject of the interaction, but the present application does not limit the execution subject of the interaction. For example, the access network device in FIG. 5 can also be a module applied to the access network device, such as a chip, a chip system, or a processor, and can also be a logic node, a logic module, or software capable of realizing all or part of the functions of the access network device. The terminal device in FIG. 5 can also be a module applied to the terminal device, such as a chip, a chip system, or a processor, and can also be a logic node, a logic module, or software capable of realizing all or part of the functions of the terminal device.

[0134] As shown in FIG. 5, the communication method includes steps S501-S502:

[0135] S501, the terminal device sends a first message to the access network device based on the GNSS information before the GNSS information of the terminal device is determined to be invalid. Correspondingly, the access network device receives the first message.

[0136] S502, the access network device sends first indication information to the terminal device according to the first message, and correspondingly, the terminal device receives the first indication information from the access network device. The first indication information is used to indicate a first parameter. The first parameter is used to determine the time advance (TA) of the terminal device for sending uplink data next time.

[0137] Based on the communication method provided by the embodiments of the present application, when the GNSS information of the terminal device is invalid, the terminal device can be triggered to send an uplink message to the network side based on the GNSS information before the GNSS information is invalid, so that the network side can adjust the TA in time based on the uplink message when the GNSS information is invalid, thereby avoiding the uplink out-of-sync problem caused by not adjusting the TA for a long time. Moreover, since the terminal device sends the uplink message based on the GNSS information before the GNSS information is invalid, when the invalid GNSS information deviates too much from the real position, the network side cannot adjust the TA through the indication information due to the limitation of the maximum TA value that can be adjusted by the network side based on the bit number of the indication information.

[0138] The following describes S501 in detail.

[0139] In S501, the GNSS information of the terminal device can be used to represent the geographical position of the terminal device. The terminal device can obtain its own GNSS information through a satellite system such as Beidou or GPS. The embodiments of the present application do not limit how the terminal device obtains the GNSS information.

[0140] In S501, the GNSS information of the terminal device is invalid, including that the terminal device cannot obtain GNSS information that can accurately represent the position of the terminal device, or the position represented by the GNSS information of the terminal device deviates from the real position of the terminal device, and the like. The terminal device can determine whether its own GNSS information is invalid based on its own implementation, and the embodiments of the present application do not make specific limitations thereon. The following introduces several possible cases in which the terminal device determines that its own GNSS information is invalid according to the embodiments of the present application.

[0141] Case one: the terminal device cannot receive GNSS signals for a period of time. For example, the terminal device cannot receive GNSS signals within 10 minutes after the last time it received GNSS signals, and the terminal device can determine that its own GNSS information is invalid.

[0142] Case two: the terminal device determines that the change rule of the GNSS signal does not conform to the movement rule of the terminal device. For example, when the terminal device is almost stationary or moves slowly, the GNSS signal received by the terminal device changes suddenly, or when the terminal device is moving, the GNSS signal received by the terminal device does not change, and the terminal device can determine that its own GNSS information is invalid.

[0143] Further, the terminal device determines that its own GNSS information is invalid, which can trigger the terminal device to perform an uplink transmission, i.e., to send a first message to the access network device.

[0144] Specifically, the terminal device can determine the time advance to be used when sending the first message based on the GNSS information before the invalidation, so as to determine the sending time of the first message according to the determined time advance.

[0145] For example, in the scenario of a transparent satellite in an NTN network, the terminal device can determine the value of the above formula (1) based on the GNSS information before the invalidation and the ephemeris information of the satellite. Further, the time advance T TA is calculated based on the above formula (1) and other related parameters, and the sending time of the first message is determined based on T TA .

[0146] The embodiments of the present application do not limit the specific form of the first message. For example, the first message can be carried in a sounding reference signal (SRS), a physical uplink control channel (PUCCH) message, a MAC CE, an RRC message, or a random access preamble (or the first message is an SRS, a PUCCH message, a MAC CE, an RRC message, or a random access preamble).

[0147] It can be understood that if the first message is carried in a random access preamble, the terminal device sending the first message is equivalent to the terminal device initiating random access. That is, S501 can also be understood as the terminal device initiating random access when it is determined that its GNSS information is invalid.

[0148] Optionally, the first message can not carry service data of the terminal device. In this case, the first message can be considered as a message specially used to trigger the network side to adjust the time advance of the terminal device.

[0149] The following will be expanded to introduce S502.

[0150] In S502, after receiving the first message, the access network device can determine that the time advance for sending uplink data of the terminal device needs to be adjusted (or corrected) according to the first message. For example, the access network device determines that the time advance for sending uplink data of the terminal device needs to be corrected based on the time when it receives the first message, which is not the starting time of the subframe.

[0151] Based on this, the access network device sends first indication information indicating the first parameter to the terminal device. After receiving the first indication information, the terminal device can determine the time advance for sending uplink data next time based on the first parameter indicated by the first indication information. That is, the first parameter includes one or more parameters required for calculating the time advance. Alternatively, the first parameter can also be the time advance calculated by the access network device.

[0152] The embodiments of the present application do not limit the specific form of the first message. For example, the first message can be carried in a sounding reference signal (SRS), a physical uplink control channel (PUCCH) message, a MAC CE, an RRC message, or a random access preamble (or the first message is an SRS, a PUCCH message, a MAC CE, an RRC message, or a random access preamble). TA TA If the formula for calculating the time advance T TA is changed later, the first parameter can also be changed accordingly, without affecting the application of the communication method provided by the embodiments of the present application. ​

[0153] Optionally, the first indication information can indicate an adjustment value of the first parameter, or can indicate an absolute value of the first parameter. Wherein, the adjustment value of the first parameter indicated by the first indication information is an adjustment value adjusted on the basis of the value of the first parameter obtained by the terminal device last time (or the value of the first parameter sent by the access network device to the terminal device last time). It can be understood that the time advance of the terminal device sending the first message is also determined on the basis of the first parameter obtained by the terminal device last time.

[0154] The message form carrying the first indication information is not limited in the embodiments of the present application. For example, the first indication information can be carried in the MAC CE. Wherein, if the first indication information indicates the adjustment value of the first parameter, the first indication information can be carried in the TA Command MAC CE, and if the first indication information indicates the absolute value of the first parameter, the first indication information can be carried in the Absolute TA Command MAC CE. For another example, if the terminal device initiates random access, such as the first message is a random access preamble, the first indication information can be carried in the RAR in the random access process.

[0155] Some optional schemes provided by the embodiments of the present application are introduced below.

[0156] Optionally, in S502, after receiving the first indication information, the terminal device can start (including starting for the first time or restarting) the first timer. During the running of the first timer, the terminal device can determine whether its own GNSS information is invalid. If it is determined that its own GNSS information is still invalid during the running of the first timer, the terminal device can send the first message to the access network device again after the first timer runs out. If it is determined that its own GNSS information is not invalid (also can be called recovery, it can be understood that the GNSS information can represent the accurate geographical position of the terminal device) during the running of the first timer, the terminal device can end the process after the first timer runs out, that is, stop sending the first message to the access network device.

[0157] Wherein, if the terminal device sends the first message to the access network device again after the first timer runs out, the sending time of the terminal device sending the first message again is determined on the basis of the current time advance of the terminal device (that is, the time advance calculated by the terminal device on the basis of the latest received first indication information indicating the first parameter).

[0158] The GNSS information that the terminal device judges whether to be invalid during running of the first timer can be new GNSS information acquired by the terminal device during running of the first timer, or can be the latest GNSS information acquired by the terminal device before starting of the first timer. For example, if the terminal device acquires new GNSS information 1 after sending the first message to the access network device, the terminal device starts the first timer after receiving the first indication information, and the terminal device can determine whether the GNSS information 1 is invalid during running of the first timer. For another example, the terminal device acquires new GNSS information 2 during running of the first timer, and the terminal device can determine whether the GNSS information 2 is invalid.

[0159] The first timer (for example, information such as a length of the first timer) can be configured to the terminal device by the access network device, or can be preconfigured by the terminal device, or can be configured in other manners, and the embodiments of the present application do not limit this.

[0160] Optionally, the mechanism of determining whether to send the first message again based on the first timer (which can also be understood as a mechanism of periodically sending the first message based on the first timer) can be indicated by the access network device to the terminal device. In this case, the access network device can send second indication information to the terminal device, and the second indication information is used to instruct the terminal device to periodically send the first message according to the first timer. After receiving the second indication information, the terminal device executes the above-mentioned mechanism according to the second indication information. Alternatively, the mechanism of periodically sending the first message based on the first timer can also be preconfigured by the terminal device.

[0161] Optionally, the mechanism of periodically sending the first message based on the first timer can have a maximum number of times or a maximum length of time, and after exceeding the maximum number of times or the maximum length of time, the terminal device will not send the first message again.

[0162] Specifically, under the limitation of the maximum number of times, the above-mentioned mechanism can be that the terminal device determines that the GNSS information of the terminal device is still invalid during running of the first timer, and the number of times of sending the first message does not exceed a first threshold, and then the terminal device sends the first message to the access network device again after the first timer ends. If the number of times of sending the first message exceeds the first threshold, the terminal device stops the mechanism and does not send the first message to the access network device after the first timer ends.

[0163] In the case that the terminal device determines that the GNSS information of the terminal device is still invalid during the running of the first timer and the duration of the invalid GNSS information does not exceed the second threshold, the above mechanism can be that the terminal device sends the first message to the access network device again after the first timer ends. If the duration of the invalid GNSS information exceeds the second threshold, the terminal device stops the mechanism and does not send the first message to the access network device after the first timer ends.

[0164] The first threshold or the second threshold can be configured by the access network device to the terminal device, or can be pre-configured by the terminal device, or can be configured in other manners, and the embodiments of the present application do not limit this.

[0165] Optionally, in the case that the terminal device determines that the GNSS information is invalid, the terminal device can send the first message to the access network device in S501, which can be performed based on the indication of the access network device. Before S501, the access network device can send third indication information to the terminal device, and the third indication information is used to indicate that the first message is sent in the case that the GNSS information is invalid. Accordingly, after the terminal device receives the third indication information, the terminal device starts to determine whether to send the first message to the access network device based on the indication of the third information based on whether the GNSS information is invalid.

[0166] Optionally, in S501, the terminal device can start the second timer in the case that the terminal device determines that the GNSS information of the terminal device is invalid. If the terminal device does not receive the information (such as the first indication information) for adjusting the time advance amount from the access network device during the running of the second timer, the terminal device sends the first message to the access network device after the running of the second timer times out. If the terminal device receives the information (such as the first indication information) for adjusting the time advance amount from the access network device during the running of the second timer, it indicates that the network side has learned that the time advance amount of the terminal device cannot realize uplink synchronization, and has issued information to correct the time advance amount. In this case, the terminal device does not need to send the first message to the access network device to trigger the network side to adjust the time advance amount.

[0167] The second timer can be configured by the access network device to the terminal device, or can be pre-configured by the terminal device, or can be configured in other manners, and the embodiments of the present application do not limit this.

[0168] Optionally, in S501, the terminal device can send a first message to the access network device in a case that the terminal device receives downlink data from the access network device and determines that the GNSS information of the terminal device is invalid. In this case, after the terminal device receives the first indication information and determines the time advance based on the first parameter, the terminal device can determine a time for sending a response message, such as an acknowledge character (ACK), to the access network device based on the time advance.

[0169] Optionally, if the terminal device has configured a timer (which can be referred to as a third timer) for determining whether the time advance currently used by the terminal device is available, for example, a TAT, in S501, the terminal device can stop the third timer in a case that the terminal device determines that the GNSS information of the terminal device is invalid, and no longer determine whether the current time advance is available through the third timer.

[0170] Optionally, in S501, the time advance used by the terminal device for sending the first message can not be largely offset compared with the correct time advance, and at this time, the network side can consider that the time advance of the terminal device does not need to be corrected. In order to avoid that the network side does not send the first indication information to the terminal device, the first message can include fourth indication information, and the fourth indication information is used to indicate that the GNSS information of the terminal device is invalid. After the access network device receives the first message, the access network device can determine that the GNSS information of the terminal device is invalid based on the fourth indication information, and needs to correct the time advance of the terminal device, and then sends the first indication information to the terminal device.

[0171] Alternatively, the first message can indicate that the GNSS information of the terminal device is invalid. For example, the terminal device and the access network device can agree on one or more dedicated random access preambles in advance to indicate the invalidity of the GNSS information. After the terminal device determines that the GNSS information is invalid, the terminal device can select one of the dedicated random access preambles as the first message and send it to the access network device. After the access network device receives the random access preamble, the access network device can determine that the GNSS information of the terminal device is invalid, needs to correct the time advance of the terminal device, and then sends the first indication information to the terminal device.

[0172] Alternatively, the fourth indication information and the first message can be sent separately. For example, if the first message sent by the terminal device is a random access preamble, the fourth indication information can be carried in other messages sent by the terminal device in the random access process, for example, can be carried in message 3 (Msg3) or message 5 (Msg5) (also known as RRC connection establishment completion message). Alternatively, the access network device determines that the GNSS information of the terminal device is invalid based on the fourth indication information, and can take some actions based on the implementation, for example, according to the network implementation, periodically or more frequently instructs the terminal device to initiate random access.

[0173] Alternatively, after receiving the first message, the access network device can send the terminal device the fifth indication information, and the fifth indication information is used to indicate to initiate random access. For example, the fifth indication information can be PDCCH order information, which is a kind of trigger information for the network side to trigger the terminal device to perform random access. After receiving the fifth indication information, the terminal device can initiate random access based on the fifth indication information and send a random access request (i.e. a random access preamble) to the access network device. Further, after the terminal device initiates random access, the access network device can carry the first indication information in the RAR sent to the terminal device to correct the time advance of the terminal device.

[0174] Alternatively, the optional schemes introduced above can be combined with each other to form different schemes. For example, after the terminal device starts the second timer, if the terminal device receives the first indication information during the running of the second timer, the terminal device can start the first timer after the second timer runs out, and determine whether to send the first message to the access network device based on whether the GNSS information is invalid during the running of the first timer.

[0175] In addition, the present application embodiment also provides an optional scheme. In this scheme, after the terminal device is in the connected state, whether the GNSS information is invalid or not, the terminal device periodically sends uplink data to the access network device, and when the terminal device has no uplink data transmission requirement, the first message is sent as the uplink data. After the terminal device leaves the connected state, the terminal device stops periodically sending uplink data. Alternatively, the access network device sends the first indication information to the terminal device to correct the time advance of the terminal device each time the uplink data is received, or the access network device can determine whether to send the first indication information to the terminal device based on the time when the uplink data is received.

[0176] In order to facilitate understanding of the communication method provided by the present application, a possible and exemplary flow of the present application is introduced as follows. As shown in FIG. 6, the exemplary flow includes the following steps:

[0177] S601 (optionally), the access network device configures a second timer for the terminal device. The second timer is described above and will not be repeated here.

[0178] S602 (optionally), the access network device configures a first timer for the terminal device. The time length of the second timer and the first timer can be the same or different. The first timer is described above and will not be repeated here.

[0179] Optionally, in S602, the access network device can also configure the terminal device with a first threshold or a second threshold. The first threshold or the second threshold is described above and will not be repeated here.

[0180] Optionally, in S602, the access network device can also send the terminal device with second indication information and / or third indication information. The second indication information or the third indication information is described above and will not be repeated here.

[0181] The information for configuring the first timer can be carried in the same message as the second indication information or the third indication information, or can be carried in different messages.

[0182] S603, the terminal device determines whether its GNSS information is invalid. If it is determined to be invalid, the terminal device can perform S607 to trigger the network side to correct the TA, or the terminal device can perform S604. If it is determined to be not invalid, the flow stops.

[0183] S603 can refer to the description of S501 above and will not be repeated here.

[0184] Optionally, if the terminal device is also configured with TAT, the terminal device can stop the TAT after determining that its GNSS information is invalid.

[0185] S604 (optionally), in the case where the second timer is configured, the terminal device starts the second timer. After starting, the terminal device performs S605.

[0186] S605 (optionally), the terminal device detects whether a TA Command MAC CE or an Absolute TA Command MAC CE (these two MAC CEs can be referred to as TA Command) from the access network device is received during running of the second timer. If the TA Command MAC CE or the Absolute TA Command MAC CE is received during running of the second timer, S610 is jumped to. If the TA Command MAC CE or the Absolute TA Command MAC CE is not received during running of the second timer, after the second timer expires, the terminal device performs S607 to trigger network-side correction of the TA.

[0187] S606 (optionally), the access network device sends downlink data to the terminal device, and correspondingly, the terminal device receives the downlink data. Since there is an ACK mechanism in the radio link control (RLC) layer and the MAC layer, the terminal device needs to send an uplink ACK after receiving the downlink data, and thus the TA needs to be corrected. Here, the terminal device receiving the downlink data can be regarded as a condition for triggering the terminal device to perform S607.

[0188] Optionally, if the terminal device is also configured with the second timer, in S606, the terminal device can receive the downlink data before or after expiration of the second timer.

[0189] S607, the terminal device sends an uplink message (i.e., a first message) to the access network device. S607 can include two possible implementation manners of S607a and S607b.

[0190] S608, after the access network device receives the first message, the access network device sends first indication information to the terminal device to indicate a first parameter to correct the TA.

[0191] S608 also has different implementation manners based on S607a and S607b. The possible implementation manners of S607-S608 are described below.

[0192] S607a, based on triggering of S603, S605 or S606, the terminal device sends an uplink message (i.e., a first message) to the access network device, for example, sends SRS, PUCCH, a MAC CE or an RRC message once. The TA used by the terminal device to send the uplink message this time is calculated based on available GNSS information before the GNSS information is invalidated.

[0193] Optionally, the terminal device carries indication information indicating GNSS information invalidity in the first message to avoid the network side considering that TA correction is not needed.

[0194] After S607a, S608a or S608b is performed.

[0195] S608a, the access network device sends TA Command MAC CE or Absolute TA Command MAC CE (i.e. first indication information) to the terminal device to indicate N TA (i.e. first parameter) to correct the TA of the terminal device.

[0196] S608b, the access network device triggers the terminal device to initiate random access, for example, the access network device sends PDCCH order information to the terminal device. In the random access process, the access network device indicates N TA (i.e. first parameter) to correct the TA of the terminal device through RAR (i.e. first indication information).

[0197] S607b, based on the trigger of S603, S605 or S606, the terminal device sends a random access preamble (i.e. first message) to the access network device. The TA used by the terminal device to send the random access preamble this time is calculated based on the available GNSS information before the GNSS information invalidity.

[0198] Optionally, the terminal device and the access network device can agree on a dedicated random access preamble to indicate GNSS information invalidity.

[0199] After S607a, S608c is performed.

[0200] S608c, the terminal device and the access network device perform subsequent steps of random access. In the random access process, the access network device indicates N TA (i.e. first parameter) to correct the TA of the terminal device through RAR (i.e. first indication information).

[0201] Optionally, the terminal device can carry indication information indicating GNSS invalidity in Msg3 or Msg5.

[0202] S609 (optionally), the terminal device starts a first timer to start counting down.

[0203] S610 (optionally), the terminal device judges whether the GNSS information is still invalid during the running of the first timer. If it is still invalid, S611 is performed, or S607 is performed again after the running of the first timer is timed out. If it is not invalid, the flow ends,

[0204] S611 (optionally), the terminal device determines whether the number of times of sending the first message reaches the maximum number or whether the duration of the GNSS information invalidation reaches the maximum duration, and if so, the flow ends. If not, after the expiration of the first timer, S607 is performed again.

[0205] Embodiments of the present application do not limit the timing between S601-S611 described above, and the timing shown in FIG. 6 is only one possible example timing and does not constitute a limitation on the timing of S601-S611. For example, S601 and S602 can occur at the same time, or the access network device can configure the first timer and the second timer together, or they can not occur at the same time, and the access network device can configure the first timer and the second timer at different times. For another example, S606 can occur before S603, and the terminal device determines whether its own GNSS information is invalid after receiving the downlink data, and if it is determined that it is not invalid, it directly sends an ACK based on the current TA, and if it is determined to be invalid, it performs S607 or S604.

[0206] In addition, if the above method embodiment is applied in the O-RAN architecture, there can be optional steps between the units in the O-RAN architecture as shown in FIG. 7:

[0207] S701, the RIC sends indication information to the gNB-CU or gNB-DU through the E2 interface, which indicates the gNB-CU or gNB-DU to configure one or more of the following for the terminal device: the first timer, the first threshold, the second threshold, and sending the first message in the case of GNSS information invalidation (i.e., the indication information can also indicate the gNB-CU or gNB-DU to send third indication information to the terminal device).

[0208] The first timer, the first threshold, the second threshold, and the third indication information can be referred to the above description and will not be expanded here.

[0209] Optionally, if the indication information indicates to configure the first timer for the terminal device, the indication information can include the duration of the first timer and other related information.

[0210] Optionally, the indication information can also include the identity of the terminal device, indicating which terminal device needs to be configured. If the indication information does not include the identity of the terminal device, it can be considered that each terminal device that has a communication connection with the gNB-CU or gNB-DU needs to be configured.

[0211] S702, the RIC sends indication information to the gNB-CU or gNB-DU through the E2 interface, which indicates the gNB-CU or gNB-DU to configure the second timer for the terminal device. The second timer can be referred to the above description and will not be expanded here.

[0212] Optionally, the indication information can include the time length of the second timer and the like.

[0213] Optionally, the indication information can further include the identifier of the terminal device, for indicating which terminal device needs to be configured. If the indication information does not include the identifier of the terminal device, it can be considered that each terminal device needs to be configured.

[0214] Correspondingly, the gNB-CU or gNB-DU can send the corresponding configuration information to the terminal device for configuration based on the indication of the RIC.

[0215] The above mainly introduces the scheme provided by the embodiments of the present application from the perspective of interaction between various network elements. Correspondingly, the embodiments of the present application further provide a communication apparatus, which is used to implement the various methods described above. The communication apparatus can be the terminal device in the method embodiments described above, or an apparatus containing the terminal device, or a component that can be used for the terminal device. Alternatively, the communication apparatus can be the access network device in the method embodiments described above, or an apparatus containing the access network device, or a component that can be used for the access network device.

[0216] It can be understood that, in order to implement the above functions, the communication apparatus contains the corresponding hardware structure and / or software module for executing various functions. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is implemented in hardware or computer software driven hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0217] The embodiments of the present application can divide the functions of the communication apparatus according to the method embodiments described above, for example, each function module can be divided according to each function, or two or more functions can be integrated in one processing module. The integrated module can be realized in the form of hardware or software function module. It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical function division. There can be another division manner in actual implementation.

[0218] FIG. 8 shows a structural schematic diagram of a communication apparatus 800. The communication apparatus 800 includes a transceiver module 801 and a processing module 802. The processing module 802, which can also be referred to as a processing unit, is used to implement processing functions. Optionally, the communication apparatus 800 can further include a storage module 803.

[0219] In a possible design, for example, the terminal device in the foregoing method embodiments is the communication apparatus 800, the processing module 802 is configured to determine whether GNSS information of the communication apparatus 800 is invalid; the transceiver module 801 is configured to send a first message to an access network device based on the GNSS information before the GNSS information is invalid, in a case where the GNSS information is invalid; and the transceiver module 801 is further configured to receive first indication information from the access network device, where the first indication information is used to indicate a first parameter, and the first parameter is used to determine a time advance of next uplink data transmission of the communication apparatus 800.

[0220] All related content of each step in the foregoing method embodiments can be referred to the function description of the corresponding functional module, and will not be repeated here.

[0221] Optionally, in the communication apparatus shown in FIG. 8, the names of the modules can also be different from those shown in FIG. 8, for example, the transceiver module can also be referred to as a communication module or a communication unit.

[0222] When each unit in FIG. 8 is implemented in the form of a software functional module and sold or used as an independent product, the software functional module can be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of the embodiments of the present disclosure essentially, or the part that contributes to the prior art, or all or a part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to perform all or part of the steps of the methods described in the embodiments of the present disclosure. The storage medium storing the computer software product includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and various other media that can store program codes.

[0223] In the embodiments of the present disclosure, the communication apparatus 800 is presented in the form of dividing various functional modules in an integrated manner. The "module" here can refer to an application-specific integrated circuit (ASIC), a circuit, a processor and a memory that execute one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions.

[0224] In a simple embodiment, those skilled in the art can think that the communication apparatus 800 can take the form of the communication apparatus 900 shown in FIG. 9.

[0225] As shown in FIG. 9, the communication device 900 includes one or more processors 901, a communication line 902, and at least one communication interface 904 (only exemplary in FIG. 9 to include the communication interface 904, and one processor 901 is exemplified for illustration), and optionally further includes a memory 903.

[0226] The processor 901 can be a general central processing unit (CPU), a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of programs of the solutions of the present application.

[0227] The communication line 902 can include a path for connecting different components.

[0228] The communication interface 904 can be a transceiver module for communicating with other devices or communication networks, such as Ethernet, RAN, terminal, wireless local area networks (WLAN), etc. For example, the transceiver module can be a transceiver, a transceiver-like device, or some other device capable of communicating with a modem, a network, a device, etc. Alternatively, the communication interface 904 can be a transceiver circuit or input / output interface within the processor 901 for enabling signal input and output of the processor.

[0229] The memory 903 can be a device with a storage function. For example, it can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to this. The memory can exist independently and be connected to the processor through the communication line 902. The memory can also be integrated with the processor.

[0230] The memory 903 is configured to store computer-executable instructions for implementing the solutions of the present application, and the processor 901 is configured to execute the computer-executable instructions stored in the memory 903. The processor 901 is configured to execute the computer-executable instructions stored in the memory 903, so as to implement the communication method provided in the embodiments of the present application.

[0231] Alternatively, the processor 901 can execute the functions related to processing in the communication method provided in the embodiments of the present application, and the communication interface 904 is responsible for communication with other devices or communication networks, which is not limited in the embodiments of the present application.

[0232] Optionally, the computer-executable instructions in the embodiments of the present application can also be referred to as application program codes, which are not limited in the embodiments of the present application.

[0233] In a specific implementation, as an embodiment, the processor 901 can include one or more CPUs, for example, CPU0 and CPU1 in FIG. 9.

[0234] In a specific implementation, as an embodiment, the communication apparatus 900 can include multiple processors, for example, the processor 901 and the processor 907 in FIG. 9. Each of the processors can be a single-core processor or a multi-core processor. The processor herein can include, but is not limited to, at least one of the following: CPU, microprocessor, digital signal processor (DSP), microcontroller unit (MCU), artificial intelligence processor, and various computing devices running software, each of which can include one or more cores for executing software instructions to perform calculations or processing.

[0235] In a specific implementation, as an embodiment, the communication apparatus 900 can further include an output device 905 and an input device 906. The output device 905 communicates with the processor 901 and can display information in various ways. For example, the output device 905 can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector, etc. The input device 906 communicates with the processor 901 and can receive user input in various ways. For example, the input device 906 can be a mouse, a keyboard, a touch screen device, a sensing device, etc.

[0236] The communication apparatus 900 described above can also be referred to as a communication device, which can be a general device or a special device. For example, the communication apparatus 900 can be the terminal device or the access network device described above or a device having a similar structure to that shown in FIG. 9. Embodiments of the present application do not limit the type of the communication apparatus 900.

[0237] In addition, the constituent structure shown in FIG. 8 does not constitute a limitation on the communication apparatus, and the communication apparatus 900 can include more or fewer components than those shown in the drawing, or some components can be combined, or different components can be arranged, in addition to the components shown in FIG. 9.

[0238] Optionally, the functions / implementation procedures of the transceiver module 801 and the processing module 802 in FIG. 8 can be implemented by the processor 901 in the communication apparatus 900 shown in FIG. 9 invoking computer-executable instructions stored in the memory 903. Alternatively, the functions / implementation procedures of the processing module 802 in FIG. 8 can be implemented by the processor 901 in the communication apparatus 900 shown in FIG. 9 invoking computer-executable instructions stored in the memory 903, and the functions / implementation procedures of the transceiver module 801 in FIG. 8 can be implemented by the communication interface 904 in the communication apparatus 900 shown in FIG. 9.

[0239] It should be understood that one or more of the above modules or units can be implemented in software, hardware, or a combination of both. When any of the above modules or units is implemented in software, the software exists in the form of computer program instructions, and is stored in a memory, and a processor can be used to execute the program instructions and implement the above method flow. The processor can be built in a SoC or an ASIC, or be a separate semiconductor chip. The processor further includes a core for executing software instructions to perform operations or processing, and can further include necessary hardware accelerators, such as an FPGA, a programmable logic device (PLD), or a logic circuit for implementing special logic operations.

[0240] When any of the above modules or units is implemented in hardware, the hardware can be any one or any combination of a CPU, a microprocessor, a DSP chip, an MCU, an artificial intelligence processor, an ASIC, a SoC, an FPGA, a PLD, a special digital circuit, a hardware accelerator, or a non-integrated discrete device, which can run necessary software or be independent of software to execute the above method flow.

[0241] Optionally, the embodiments of the present application further provide a communication apparatus (for example, the communication apparatus can be a chip or a chip system), which comprises a processor, and is configured to implement the method in any of the method embodiments. In a possible design, the communication apparatus further comprises a memory. The memory is configured to store necessary program instructions and data. The processor can invoke the program code stored in the memory to instruct the communication apparatus to perform the method in any of the method embodiments. Of course, the memory can also not be in the communication apparatus. When the communication apparatus is a chip system, the communication apparatus can be composed of a chip or can comprise a chip and other discrete devices, and the embodiments of the present application do not make a specific limitation in this regard.

[0242] Optionally, the embodiments of the present application further provide a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are run on a communication apparatus, the communication apparatus can perform the method in any of the method embodiments or any implementation manner thereof.

[0243] Optionally, the embodiments of the present application further provide a computer program product, which stores a computer program or instructions, and when the computer program or instructions are run on a communication apparatus, the communication apparatus can perform the method in any of the method embodiments or any implementation manner thereof.

[0244] Optionally, the embodiments of the present application further provide a communication system, which comprises the terminal device in the method embodiments and the access network device in the method embodiments.

[0245] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions according to the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium, or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any available medium that can be accessed by a computer or data storage device including one or more servers, data centers, etc. integrated with the medium. The available medium can be magnetic medium (such as floppy disk, hard disk, magnetic tape), optical medium (such as DVD), or semiconductor medium (such as solid state drive (SSD)) and the like.

[0246] Although the present application is described herein in conjunction with various embodiments, it is understood that other variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from an inspection of the drawings, the disclosure, and the appended claims. The word "comprising" does not exclude other components or steps not listed in the claims, "a" or "an" does not exclude a plurality, and a single processor or other unit can fulfill the functions of several means recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to an advantage.

[0247] Although the present application is described herein in conjunction with specific features and embodiments thereof, it is understood that modifications and combinations can occur to those skilled in the art to which the present application pertains, within its scope, without departing from the scope of the present application. Accordingly, the description and drawings are to be regarded as illustrative in nature and are not to be regarded as limiting the scope of the application as defined in the appended claims. Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the scope of the present application. Thus, it is intended that the present application encompass such modifications and changes as fall within the scope of the appended claims and their equivalents.

Claims

1. A communication method, characterized in that: The method comprises: When it is determined that the global satellite navigation system GNSS information of the terminal device is invalid, sending a first message to the access network device based on the GNSS information before the invalidation; Receive first indication information from the access network device, where the first indication information is used to indicate a first parameter, and the first parameter is used to determine the time advance for the terminal device to send uplink data next time.

2. The method according to claim 1, characterized in that After receiving the first indication information from the access network device, the method further includes: Starting a first timer; When it is determined that the GNSS information of the terminal device is still invalid during the operation of the first timer, after the first timer expires, the first message is sent to the access network device again based on the first indication information.

3. The method according to claim 2, characterized in that The first timer is configured by the access network device to the terminal device; or, The first timer is preconfigured by the terminal device.

4. The method according to claim 2 or 3, characterized in that The method further comprises: Receive second indication information from the access network device, where the second indication information is used to instruct the terminal device to periodically send the first message according to the first timer.

5. The method according to any one of claims 2 to 4, characterized in that: The step of, in a case where it is determined that the GNSS information of the terminal device is still invalid during the running of the first timer, again sending the first message to the access network device after the first timer ends, includes: When it is determined that the GNSS information of the terminal device is still invalid during the operation of the first timer and the number of times the first message has been sent does not exceed a first threshold, after the first timer expires, the first message is sent to the access network device again; or When it is determined that the GNSS information of the terminal device is still invalid during the operation of the first timer and the duration of the GNSS information invalidation does not exceed the second threshold, after the first timer ends, the first message is sent to the access network device again.

6. The method according to claim 5, characterized in that The first threshold or the second threshold is configured by the access network device for the terminal device; or, The first threshold or the second threshold is preconfigured by the terminal device.

7. The method according to any one of claims 1 to 6, characterized in that The method further comprises: Receive third indication information from the access network device, where the third indication information is used to instruct to send the first message when GNSS information fails.

8. The method according to any one of claims 1 to 7, characterized in that The sending a first message to the access network device when it is determined that the global satellite navigation system GNSS information of the terminal device is invalid includes: When it is determined that the GNSS information of the terminal device is invalid, starting a second timer; If the terminal device does not receive the first indication information from the access network device during the operation of the second timer, the terminal device sends the first message to the access network device after the second timer expires.

9. The method according to claim 8, characterized in that The second timer is configured by the access network device for the terminal device; or, The second timer is preconfigured by the terminal device.

10. The method according to any one of claims 1 to 7, characterized in that The sending of a first message to the access network device when determining that the global satellite navigation system GNSS information of the terminal device is invalid includes: When the terminal device receives downlink data from the access network device and determines that the GNSS information of the terminal device is invalid, the first message is sent to the access network device.

11. The method according to any one of claims 1 to 10, characterized in that When it is determined that the global satellite navigation system GNSS information of the terminal device is invalid, the method further includes: Stop a third timer; the third timer is used to determine whether the time advance currently used by the terminal device is available.

12. The method according to any one of claims 1 to 11, characterized in that The first message is carried in a sounding reference signal SRS, a physical uplink control channel PUCCH message, a media access control layer control element MAC CE, a radio resource control RRC message or a random access preamble.

13. The method according to any one of claims 1 to 12, characterized in that The first message includes fourth indication information, and the fourth indication information is used to indicate that the GNSS information of the terminal device is invalid; or, The first message is used to indicate that the GNSS information of the terminal device is invalid.

14. The method according to any one of claims 1 to 13, characterized in that The first indication information is carried in a MAC CE, or the first indication information is carried in a random access response message RAR in a random access process.

15. The method according to claim 14, characterized in that The first indication information is carried in a RAR in a random access process. Before receiving the first indication information from the access network device, the method further includes: receiving fifth indication information from the access network device, where the fifth indication information is used to instruct initiation of random access; According to the fifth indication information, a random access request is sent to the access network device.

16. The method according to any one of claims 1 to 15, characterized in that The sending a first message to the access network device based on the GNSS information before the failure includes: Calculating a timing advance based on the GNSS information before the failure; The first message is sent to the access network device; the sending time of the first message is determined according to the time advance.

17. A communication system, characterized in that: The communication system includes terminal equipment and access network equipment; The terminal device is configured to, when determining that the global satellite navigation system GNSS information of the terminal device is invalid, send a first message to the access network device based on the GNSS information before the invalidation; The access network device is configured to receive the first message and, based on the first message, send first indication information to the access network device; the first indication information is used to indicate a first parameter, and the first parameter is used to determine a timing advance for the next uplink data transmission by the terminal device; The terminal device is further used to receive the first indication information.

18. A communication device, characterized in that: The communication device includes a module or unit for implementing the method according to any one of claims 1 to 16.

19. The device according to claim 18, characterized in that The communication device is a chip or a chip system.

20. A communication device, characterized in that: The communication device includes: a processor and an interface circuit, the interface circuit is used to communicate with a device outside the communication device, and the processor is used to execute instructions stored in a memory; when the instructions are executed by the processor, the communication device executes the method according to any one of claims 1 to 16.

21. The device according to claim 20, characterized in that The communication device further includes the memory.

22. The device according to claim 20 or 21, characterized in that The communication device is a chip or a chip system.

23. A computer-readable storage medium, characterized in that Instructions are stored thereon, and when the instructions are executed by a computer, the method according to any one of claims 1 to 16 is performed.

24. A computer program product, characterized in that Instructions are stored thereon, and when the instructions are executed by a computer, the method according to any one of claims 1 to 16 is performed.

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