CN111867040A - A communication method, terminal device and network device - Google Patents

Abstract

The present application discloses a communication method, which includes: a terminal device obtains a time corresponding to a frame boundary of a first system, an identifier of the first system frame, and reference information of transmission delay. The terminal device determines the time corresponding to the second system frame boundary of the terminal device according to the first time information and the transmission delay reference information, and the frame identifiers of the first system frame and the second system frame are the same. Through the solution disclosed in the present application, the terminal device can obtain a more accurate absolute time, thereby completing the synchronization with the network device and improving the synchronization accuracy.

Description

A communication method, terminal device and network device

technical field

The present application relates to the field of communication technologies, and in particular, to a communication method.

Background technique

In the mobile communication system, each terminal device has an internal time, that is, a local clock, which is managed by the clock device of the terminal device. Since the local clock of each terminal device runs independently, the local clock of each terminal device The clocks of the network equipment are not necessarily synchronized. Generally speaking, time synchronization refers to the process of making absolute clocks between different systems reach a synchronized state through the interaction of time information. In some communication scenarios, clock synchronization between a network device and a terminal device or clock synchronization between a terminal device and a terminal device is a necessary condition to ensure communication performance.

To ensure time synchronization, the terminal device may obtain clock reference information from the network device to perform time synchronization with the network device. In the fifth generation (5th generation, 5G) mobile communication system, the network device can send the absolute time to the terminal device through a broadcast message or a unicast message.

Currently, architectures utilizing non-terrestrial networks (NTN) for communication are under study. Compared with the terrestrial network system, in the NTN system, the distance between the network equipment and the terminal equipment is farther, and a large transmission delay will be introduced in the communication process. The introduction of the transmission delay will bring about the existing time synchronization process. A large error cannot meet the time synchronization requirements of communication scenarios. Therefore, in the NTN system, how to accurately synchronize the time between the terminal device and the network device needs to be solved urgently.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a communication method, a terminal device, a network device, and a storage medium, so that the terminal device can be synchronized with the network device correctly and efficiently, and the synchronization accuracy is improved.

In order to solve the above-mentioned technical problems, the embodiments of the present application provide the following technical solutions:

A first aspect of the present application provides a communication method, which can be applied to various communication systems, such as: long term evolution (long term evolution, LTE) system, LTE frequency division duplex (FDD) system, LTE time division Duplex (time division duplex, TDD), fifth generation (5th generation, 5G) mobile communication systems or new radio (new radio, NR) communication systems and future mobile communication systems, etc. It may include: the terminal device obtains a first message, where the first message carries first time information, an identifier of the first system frame and transmission delay reference information, and the first time information is the time corresponding to the boundary of the first system frame. The terminal device may obtain the first message in different ways. For example, the terminal device may receive a broadcast message sent by the network device, or the terminal device may send a request message to the network device to request the network device to send the first message. The terminal device determines the second time according to the first time information and the transmission delay reference information, and the second time is the time corresponding to the second system frame boundary of the terminal device. In a specific implementation manner, the frame number of the second system frame may be the same as the frame number of the first system frame. For example, after the terminal device completes downlink synchronization with the network device, the first system frame corresponds to the second system frame. Assuming that the propagation delay between the terminal device and the network device determined by the terminal device according to the transmission delay reference information is t1, and assuming that the time corresponding to the frame boundary of the first system is T1, the second time can be T1+t1, and the second time is the moment corresponding to the frame boundary of the second system of the terminal device, and the frame number of the second system frame is the same as the frame number of the first system frame. In a specific embodiment, the frame number of the second system frame is different from that of the first system frame. For example, it is assumed that the transmission delay reference information is a preset time, the preset time is stored in the network device in advance, and the preset time is the estimated transmission delay between the network device and the terminal device. Assuming that the preset time is the duration of one system frame, if the network device sends time information of an absolute time corresponding to the end boundary of system frame 1 . Then, the terminal device adjusts the absolute time corresponding to the end boundary of system frame 2 on the terminal device side according to the absolute time corresponding to the end boundary of system frame 1 indicated by the network device side. At this time, after the terminal device completes the downlink synchronization with the network device, the system frame 1 on the network device side corresponds to the system frame 1 on the terminal device side, and the system frame 2 on the terminal device side corresponds to the frame number of the second system frame, and the system frame 1 is equivalent to the frame number of the first system frame, and the frame number of the second system frame is different from the frame number of the first system frame. It can be seen from the first aspect that the terminal device can determine the time corresponding to the second system frame boundary of the terminal device according to the first time information and the transmission delay reference information, so that the terminal device can obtain a more accurate absolute time, and then complete the communication with the network device. synchronization to improve synchronization accuracy.

Optionally, in combination with the above-mentioned first aspect, in a first possible implementation manner, the transmission delay reference information is location information of the network device. The determining of the second time by the terminal device according to the first time information and the transmission delay reference information may include: the terminal device determining the second time according to the first time information and the first transmission delay. The first transmission delay is determined according to the location information of the network device and the location information of the terminal device. It can be known from the first possible implementation manner of the first aspect that the terminal device can determine the first transmission delay between the network device and the terminal device according to the location information of the network device and the location information of the terminal device, and the absolute time sent by the network device Combined with the first transmission delay, the terminal device can obtain a more accurate absolute time, thereby completing the synchronization with the network device and improving the synchronization accuracy.

Optionally, in combination with the above-mentioned first aspect, in a second possible implementation manner, the transmission delay reference information is the second transmission delay between the network device and the first location. The terminal device determining the second time according to the first time information and the transmission delay reference information may include: the terminal device determining the second time according to the first time information, the second transmission delay and the third transmission delay. The third transmission delay is determined according to the terminal device and the first location. The first position is a preset or defined position or the first position is a reference position.

Optionally, in combination with the above-mentioned first aspect, in a third possible implementation manner, the transmission delay reference information is the transmission power of the network device. The terminal device determining the second time according to the first time information and the transmission delay reference information may include: the terminal device determining the second time according to the first time information and the fourth transmission delay. The fourth transmission delay is the transmission delay between the network device and the terminal device determined according to the path power loss, and the path power loss is determined according to the transmit power of the network device.

Optionally, in combination with the third possible implementation manner of the first aspect, in a fourth possible implementation manner, the fourth transmission delay is based on one or more of path power loss, information transmission frequency, and information transmission speed. The path power loss is determined according to the transmit power of the network device and the receive power of the terminal device.

A second aspect of the present application provides a communication method, which may include:

The terminal device acquires the first message, where the first message carries the first time information and the identifier of the first system frame, and the first time information is the time corresponding to the boundary of the first system frame. The terminal device determines the second time according to the first time information and the timing advance TA, the second time is the time corresponding to the second system frame boundary of the terminal device, and the frame identifiers of the first system frame and the second system frame are the same.

Optionally, in combination with the above second aspect, in a first possible implementation manner, wherein: TA corresponds to a first timer, and the duration of the first timer is T. Before the terminal device determines the second time according to the first time information and the TA, the method may further include: the terminal device determines that the first timer has not timed out.

Optionally, in combination with the first possible implementation manner of the foregoing second aspect, in the second possible implementation manner, the duration T is configured by the network device. Or the duration T is determined by the terminal device according to the movement state. Alternatively, the duration T is determined by the terminal device according to the movement state and the configuration of the network device.

A third aspect of the present application provides a communication method, which may include: a network device sends a first message, where the first message carries first time information, an identifier of the first system frame, and transmission delay reference information, and the first time information is the first time information. The time corresponding to the frame boundary of a system, the first time information and the transmission delay reference information are used to indicate the second time, the second time is the time corresponding to the frame boundary of the second system of the terminal equipment, the first system frame and the second system frame The frame ID is the same.

Optionally, in combination with the above third aspect, in a first possible implementation manner, the transmission delay reference information is the location information of the network device, and the location information of the network device is used to indicate the first time between the network device and the terminal device. a transmission delay.

Optionally, in combination with the above third aspect, in a second possible implementation manner, the transmission delay reference information is the second transmission delay between the network device and the first location, and the first location is preset or defined. The position or the first position is the reference position. The second transmission delay indicates the second time instant.

Optionally, in combination with the above third aspect, in a third possible implementation manner, the transmission delay reference information is the transmission power of the network device, the transmission power indicates the path power loss, and the path power loss is related to the difference between the terminal device and the network device. is related to the fourth transmission delay in between.

A fourth aspect of the present application provides a communication method, which may include: a network device sending a first message, where the first message carries first time information and an identifier of the first system frame. The network device sends the timing advance TA, the first time information and TA are used by the terminal device to determine the second time, the second time is the time corresponding to the second system frame boundary of the terminal device, the frame of the first system frame and the second system frame Identifies the same.

Optionally, in combination with the above fourth aspect, in a first possible implementation manner, the method may further include: the network device configures the duration of the first timer of the terminal device to be T, and the first timer is not timed out for the terminal The device determines that the TA is valid.

A fifth aspect of the present application provides a communication method, which may include: obtaining a first system message by a terminal device, where the first system message carries second time information and transmission delay reference information, and the second time information is the information used for sending the first system message. The moment corresponding to the boundary of the first time window. The terminal device determines a third time according to the second time information and the transmission delay reference information, where the third time corresponds to the boundary of the second time window for receiving the first system message, and the first time window and the second time window are the same.

Optionally, in combination with the above fifth aspect, in a first possible implementation manner, the transmission delay reference information is location information of the network device. The method may further include: the terminal device determining the first transmission delay between the network device and the terminal device according to the location information of the network device and the location information of the terminal device. The determining of the third time by the terminal device according to the second time information and the transmission delay reference information may include: the terminal device determining the third time according to the second time information and the first transmission delay.

Optionally, in combination with the above fifth aspect, in a second possible implementation manner, the transmission delay reference information is the second transmission delay between the network device and the first location. The first position is a preset or defined position or the first position is a reference position. The method may further include: the terminal device determining a third transmission delay between the terminal device and the first location. The terminal device determining the third time according to the second time information and the transmission delay reference information may include: the terminal device determining the third time according to the second time information, the second transmission delay and the third transmission delay.

Optionally, in combination with the above fifth aspect, in a third possible implementation manner, the transmission delay reference information is the transmission power of the network device. The method may further include: the terminal device determines a fourth transmission delay from the network device to the terminal device according to the path power loss, where the path power loss is determined according to the transmission power of the network device. The determining of the third time by the terminal device according to the second time information and the transmission delay reference information may include: the terminal device determining the third time according to the second time information and the fourth transmission delay.

Optionally, in combination with the third possible implementation manner of the fifth aspect, in the fourth possible implementation manner, the terminal device determines the fourth transmission delay from the network device to the terminal device according to the path power loss, and the path power loss is Determined according to the transmission power of the network device, which may include: the terminal device determines the fourth transmission delay from the network device to the terminal device according to the path power loss, the information transmission frequency and the information transmission speed, and the path power loss is determined according to the transmission power and the transmission power of the network device. The received power of the terminal equipment is determined.

A sixth aspect of the present application provides a communication method, which may include: acquiring a first system message by a terminal device, where the first system message carries second time information, and the second time information corresponds to the boundary of the first time window for sending the first system message moment. The terminal device determines a third time according to the second time information and the timing advance TA, where the third time corresponds to the boundary of the second time window for receiving the first system message, and the first time window and the second time window are the same.

Optionally, in combination with the above sixth aspect, in a first possible implementation manner, wherein: TA corresponds to the first timer, and the duration of the first timer is T. Before the terminal device determines the third time according to the second time information and the TA, the method may further include: the terminal device determines that the first timer has not timed out.

Optionally, in combination with the first possible implementation manner of the sixth aspect, in the second possible implementation manner, the duration T is configured by the network device. Or the duration T is determined by the terminal device according to the movement state. Alternatively, the duration T is determined by the terminal device according to the movement state and the configuration of the network device.

A seventh aspect of the present application provides a communication method. In order to ensure that a terminal device can correctly receive an SIB message, a system information window (SI-window) is defined. The SI-window can also be called a time window, that is, the network device sends System messages have a periodic SI-window, which is a fixed duration. In this embodiment of the present application, different SIs may be mapped to the same SI-window or to different SI-windows, and the SI-windows corresponding to different SIs may overlap (specifically, some time-frequency resources overlap), or may not overlapping. The terminal device needs to monitor the starting position of the SI-window until the SIB message in the SI is successfully received. It may include: the network device sends a first system message, the first system message carries second time information and transmission delay reference information, the second time information is the time corresponding to the boundary of the first time window for sending the first system message, the first The system message is used by the terminal device to determine a third time, and the third time is the time corresponding to the boundary of the second time window for receiving the first system message, and the first time window and the second time window are the same.

Optionally, in combination with the above seventh aspect, in a first possible implementation manner, the transmission delay reference information is the location information of the network device, and the location information of the network device is used by the terminal device to determine the distance between the network device and the terminal device. The first transmission delay.

Optionally, in combination with the above seventh aspect, in a second possible implementation manner, the transmission delay reference information is the second transmission delay between the network device and the first location, and the first location is preset or defined. The position or the first position is the reference position. The second transmission delay is used by the terminal device to determine the third time in combination with the third transmission delay and the second time information, and the third transmission delay is the transmission delay between the terminal device and the first position.

Optionally, in combination with the above seventh aspect, in a third possible implementation manner, the transmission delay reference information is the transmission power of the network device, the transmission power is used by the terminal device to determine the path power loss, and the path power loss is used by the terminal device. A fourth transmission delay between the terminal device and the network device is determined.

An eighth aspect of the present application provides a communication method, which may include: a network device sends a first system message, the first system message carries second time information, and the second time information corresponds to a first time window boundary for sending the first system message moment. The network device sends the timing advance TA, the first system message and TA are used by the terminal device to determine the third time, the third time is the time corresponding to the boundary of the second time window for receiving the first system message, the first time window and the second time windows are the same.

Optionally, in combination with the above eighth aspect, in a first possible implementation manner, the method may further include: the network device configures the duration of the first timer of the terminal device to be T, and the first timer does not expire for the terminal The device determines that the TA is valid.

A ninth aspect of the present application provides a terminal device, where the terminal device has the function of implementing the method of any possible implementation manner of the first aspect or the second aspect or the fifth aspect or the sixth aspect. This function can be implemented by hardware or by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above functions.

A tenth aspect of the present application provides a network device, the network device having the function of implementing the method of any possible implementation manner of the third aspect or the fourth aspect or the seventh aspect or the eighth aspect. This function can be implemented by hardware or by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above functions.

An eleventh aspect of the present application provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, when the computer-readable storage medium runs on a computer, the computer can execute the first aspect or the second aspect or the fifth aspect Or the communication method of any possible implementation manner of the sixth aspect.

A twelfth aspect of the present application provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, when executed on a computer, the computer can execute the third aspect or the fourth aspect or the seventh aspect Or the communication method of any possible implementation manner of the eighth aspect.

A thirteenth aspect of the present application provides a computer program product containing instructions, which, when run on a computer, enables the computer to execute any possible implementation of the first aspect or the second aspect or the fifth aspect or the sixth aspect communication method.

A fourteenth aspect of the present application provides a computer program product containing instructions, which, when run on a computer, enables the computer to execute any possible implementation manner of the third aspect or the fourth aspect or the seventh aspect or the eighth aspect communication method.

A fifteenth aspect of the present application provides a chip system, where the chip system includes a processor configured to support a terminal device to implement any of the possible implementation manners of the first aspect or the second aspect or the fifth aspect or the sixth aspect. functions involved. In a possible design, the chip system further includes a memory for storing necessary program instructions and data of the terminal device. The chip system may be composed of chips, or may include chips and other discrete devices. The chip system may include an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices. Further, the chip system may further include an interface circuit and the like.

A sixteenth aspect of the present application provides a chip system, where the chip system includes a processor, configured to support a network device to implement any of the above-mentioned third aspect or the fourth aspect or the seventh aspect or the eighth aspect in any possible implementation manner. functions involved. In a possible design, the chip system further includes a memory for storing necessary program instructions and data of the network device. The chip system may be composed of chips, or may include chips and other discrete devices.

A seventeenth aspect of the present application provides a terminal device, which may include: a transceiver unit configured to acquire a first message, where the first message carries first time information, an identifier of the first system frame, and transmission delay reference information, and the first message The time information is the time corresponding to the frame boundary of the first system. The processing unit is configured to determine the second time according to the first time information and the transmission delay reference information obtained by the obtaining unit, where the second time is the time corresponding to the second system frame boundary of the terminal device, the first system frame and the second system frame The frame ID is the same.

Optionally, in combination with the above seventeenth aspect, in a first possible implementation manner, the transmission delay reference information is location information of the network device. The processing unit is specifically configured to determine the second time according to the first time information and the first transmission delay. The first transmission delay is determined according to the location information of the network device and the location information of the terminal device.

Optionally, in combination with the above seventeenth aspect, in a second possible implementation manner, the transmission delay reference information is the second transmission delay between the network device and the first location. The first position is a preset or defined position or the first position is a reference position. The processing unit is specifically configured to determine the second moment according to the first time information, the second transmission delay and the third transmission delay, wherein the third transmission delay is determined according to the terminal device and the first position.

Optionally, in combination with the above seventeenth aspect, in a third possible implementation manner, the transmission delay reference information is the transmission power of the network device. The processing unit is specifically configured to determine the second moment according to the first time information and the fourth transmission delay, where the fourth transmission delay is determined according to the path loss, the transmission delay between the network device and the terminal device, the path power The loss is determined based on the transmit power of the network equipment.

Optionally, in combination with the third possible implementation manner of the seventeenth aspect, in a fourth possible implementation manner, the fourth transmission delay is based on one of path power loss, information transmission frequency and information transmission speed or Multiple determinations, the path power loss is determined according to the transmit power of the network device and the receive power of the terminal device.

An eighteenth aspect of the present application provides a terminal device, which may include:

The transceiver unit is configured to acquire a first message, where the first message carries first time information and an identifier of the first system frame, and the first time information is the time corresponding to the boundary of the first system frame.

The processing unit is configured to determine the second time according to the first time information and the timing advance TA obtained by the transceiver unit, where the second time is the time corresponding to the second system frame boundary of the terminal device, and the difference between the first system frame and the second system frame is The frame ID is the same.

Optionally, in combination with the above-mentioned eighteenth aspect, in a first possible implementation manner, wherein: TA corresponds to the first timer, and the duration of the first timer is T. Before the terminal device determines the second time according to the first time information and the TA, the processing unit is further configured to determine that the first timer has not timed out.

Optionally, in combination with the first possible implementation manner of the eighteenth aspect, in the second possible implementation manner, the duration T is configured by the network device. Or the duration T is determined by the terminal device according to the movement state. Alternatively, the duration T is determined by the terminal device according to the movement state and the configuration of the network device.

A nineteenth aspect of the present application provides a network device, which may include: a transceiver unit configured to send a first message, where the first message carries first time information, an identifier of the first system frame, and transmission delay reference information, the first The time information is the time corresponding to the frame boundary of the first system, the first time information and the transmission delay reference information are used to indicate the second time, the second time is the time corresponding to the frame boundary of the second system of the terminal device, and the first system frame and The frame identification of the second system frame is the same.

Optionally, in combination with the above-mentioned nineteenth aspect, in a first possible implementation manner, the transmission delay reference information is the location information of the network device, and the location information of the network device indicates the first connection between the network device and the terminal device. transmission delay.

Optionally, in combination with the above-mentioned nineteenth aspect, in a second possible implementation manner, the transmission delay reference information is the second transmission delay between the network device and the first location, and the first location is a preset or The defined position or the first position is the reference position. The second transmission delay indicates the second time instant.

Optionally, in combination with the above-mentioned nineteenth aspect, in a third possible implementation manner, the transmission delay reference information is the transmission power of the network device, the transmission power indicates the path power loss, and the path power loss is related to the terminal device and the network device. related to the fourth transmission delay between.

A twentieth aspect of the present application provides a network device, which may include: a transceiver unit configured to send a first message, where the first message carries first time information and an identifier of a first system frame. The transceiver unit is also used to send the timing advance amount TA, the first time information and TA are used by the terminal device to determine the second time, the second time is the time corresponding to the second system frame boundary of the terminal device, the first system frame and the second time. The frame ID of the system frame is the same.

Optionally, in combination with the above-mentioned twentieth aspect, in a first possible implementation manner, it may further include: a processing unit configured to configure the duration of the first timer of the terminal device to be T, and the first timer is not timed out. The terminal device determines that the TA is valid.

A twenty-first aspect of the present application provides a terminal device, which may include: a transceiver unit configured to acquire a first system message, where the first system message carries second time information and transmission delay reference information, and the second time information is for sending The time corresponding to the first time window boundary of the first system message. The processing unit is configured to determine a third time according to the second time information and the transmission delay reference information obtained by the obtaining unit, where the third time is the time corresponding to the boundary of the second time window for receiving the first system message, the first time window and the first time window The two time windows are the same.

Optionally, in combination with the above twenty-first aspect, in a first possible implementation manner, the transmission delay reference information is location information of a network device. The processing unit is further configured to determine the first transmission delay between the network device and the terminal device according to the location information of the network device and the location information of the terminal device. The processing unit is specifically configured to determine the third time according to the second time information and the first transmission delay.

Optionally, in combination with the above twenty-first aspect, in a second possible implementation manner, the transmission delay reference information is the second transmission delay between the network device and the first location. The first position is a preset or defined position or the first position is a reference position. The processing unit is further configured to determine a third transmission delay between the terminal device and the first location. The processing unit is specifically configured to determine the third time point according to the second time information, the second transmission delay, and the third transmission delay.

Optionally, in combination with the above twenty-first aspect, in a third possible implementation manner, the transmission delay reference information is the transmission power of the network device. The processing unit is further configured to determine the fourth transmission delay from the network device to the terminal device according to the path power loss, where the path power loss is determined according to the transmission power of the network device. The processing unit is specifically configured to determine the third time according to the second time information and the fourth transmission delay.

Optionally, in combination with the third possible implementation manner of the twenty-first aspect, in the fourth possible implementation manner, the processing unit is specifically configured to determine the network device according to the path power loss, the information transmission frequency and the information transmission speed. The fourth transmission delay to the terminal device and the path power loss are determined according to the transmit power of the network device and the receive power of the terminal device.

A twenty-second aspect of the present application provides a communication method, which may include: a transceiver unit configured to acquire a first system message, where the first system message carries second time information, and the second time information is the first system message that sends the first system message. The time corresponding to the boundary of a time window. The processing unit is configured to determine a third time according to the second time information and the timing advance TA obtained by the transceiver unit, where the third time is the time corresponding to the boundary of the second time window for receiving the first system message, the first time window and the second time window The time window is the same.

Optionally, in combination with the above twenty-second aspect, in a first possible implementation manner, wherein: TA corresponds to the first timer, and the duration of the first timer is T. Before the terminal device determines the third time according to the second time information and the TA, the processing unit is further configured to determine that the first timer has not timed out.

Optionally, in combination with the first possible implementation manner of the above twenty-second aspect, in the second possible implementation manner, the duration T is configured by the network device. Or the duration T is determined by the terminal device according to the movement state. Alternatively, the duration T is determined by the terminal device according to the movement state and the configuration of the network device.

A twenty-third aspect of the present application provides a network device, which may include: a transceiver unit configured to send a first system message, where the first system message carries second time information and transmission delay reference information, and the second time information is for sending The time corresponding to the first time window boundary of the first system message, the first system message is used by the terminal device to determine the third time, and the third time is the time corresponding to the second time window boundary of receiving the first system message, and the first time window Same as the second time window.

Optionally, in combination with the above twenty-third aspect, in a first possible implementation manner, the transmission delay reference information is the location information of the network device, and the location information of the network device is used by the terminal device to determine the relationship between the network device and the terminal device. the first transmission delay between.

Optionally, in combination with the above twenty-third aspect, in a second possible implementation manner, the transmission delay reference information is the second transmission delay between the network device and the first location, and the first location is preset. Either the defined position or the first position is the reference position. The second transmission delay is used by the terminal device to determine the third time in combination with the third transmission delay and the second time information, and the third transmission delay is the transmission delay between the terminal device and the first position.

Optionally, in combination with the above twenty-third aspect, in a third possible implementation manner, the transmission delay reference information is the transmission power of the network device, the transmission power is used by the terminal device to determine the path power loss, and the path power loss is used for The terminal device determines the fourth transmission delay between the terminal device and the network device.

A twenty-fourth aspect of the present application provides a network device, which may include: a transceiver unit configured to send a first system message, where the first system message carries second time information, and the second time information is the first system message for sending the first system message. The time corresponding to the boundary of a time window. The transceiver unit is also used for sending the timing advance TA, the first system message and TA are used by the terminal device to determine the third time, the third time is the time corresponding to the boundary of the second time window for receiving the first system message, and the first time window Same as the second time window.

Optionally, in combination with the above twenty-fourth aspect, in a first possible implementation manner, it may further include: a processing unit configured to configure the duration of the first timer of the terminal device to be T, and the first timer has not timed out Used by the terminal device to determine that the TA is valid.

The embodiment of the present application enables the terminal device to obtain a more accurate absolute time, thereby completing the synchronization with the network device, and improving the synchronization accuracy.

Description of drawings

FIG. 1a is a schematic diagram of a wireless communication system applicable to an embodiment of the present application;

FIG. 1b is another schematic diagram of a wireless communication system applicable to an embodiment of the present application;

Figure 2 is a schematic diagram of system frame synchronization between terminal equipment and network equipment after downlink synchronization of the 5G communication system;

3 is a schematic diagram of the deviation between the absolute time sent by the network device and the absolute time determined by the terminal device;

FIG. 4 is a schematic diagram of an embodiment of a communication method in an embodiment of the present application;

FIG. 5 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application;

6 is a schematic diagram of another embodiment of the communication method in the application embodiment;

FIG. 7 is another schematic diagram of a wireless communication system applicable to an embodiment of the present application;

FIG. 8 is another schematic diagram of a wireless communication system applicable to an embodiment of the present application;

FIG. 9 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application;

FIG. 10 is a schematic diagram of another embodiment of the communication method in the embodiment of the application;

FIG. 11 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application;

FIG. 12 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application;

13 is a schematic diagram of the hardware structure of a communication device provided by an embodiment of the present application;

FIG. 14 is a schematic structural diagram of a terminal device provided by an embodiment of the present application;

15 is a schematic diagram of a hardware structure of another communication device provided by an embodiment of the present application;

FIG. 16 is a schematic structural diagram of a network device provided by an embodiment of the present application.

Detailed ways

The embodiments of the present application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Those of ordinary skill in the art know that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

Embodiments of the present application provide a communication method, a terminal device, a network device, and a storage medium. The terminal device determines the time corresponding to the frame boundary of the second system according to the obtained time corresponding to the frame boundary of the first system and the transmission delay reference information. The frame identifiers of the first system frame and the second system frame are the same, which ensures that the terminal device can obtain a more accurate absolute time and perform time synchronization with the network device. Each of them will be described in detail below.

The terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances so that the embodiments described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or modules is not necessarily limited to those expressly listed Rather, those steps or modules may include other steps or modules not expressly listed or inherent to the process, method, product or apparatus. The naming or numbering of the steps in this application does not mean that the steps in the method flow must be executed in the time/logical sequence indicated by the naming or numbering, and the named or numbered process steps can be implemented according to the The technical purpose is to change the execution order, as long as the same or similar technical effects can be achieved. The division of modules in this application is a logical division. In practical applications, there may be other divisions. For example, multiple modules may be combined or integrated into another system, or some features may be ignored. , or not implemented, in addition, the shown or discussed mutual coupling or direct coupling or communication connection may be through some ports, and the indirect coupling or communication connection between modules may be electrical or other similar forms. There are no restrictions in the application. In addition, the modules or sub-modules described as separate components may or may not be physically separated, may or may not be physical modules, or may be distributed into multiple circuit modules, and some or all of them may be selected according to actual needs. module to achieve the purpose of the solution of this application.

It should be noted that, in this embodiment of the present application, "predefined" or "preset" means that a corresponding code, a table, or other information that can be used to indicate relevant information can be pre-stored in a device (for example, including a terminal device and a network device). This application does not limit its specific implementation. For example, pre-defined may refer to the definition in the protocol.

It should also be noted that, in the embodiments of the present application, the terms "network" and "system" are often used interchangeably, but those skilled in the art can understand their meanings. Information (information), signal (signal), message (message), and channel (channel) can sometimes be mixed.

The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: long term evolution (longtermevolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD) system ), fifth generation (5th generation, 5G) mobile communication system or new radio (new radio, NR) communication system and future mobile communication system, etc.

To facilitate understanding of the embodiments of the present application, the communication systems applicable to the embodiments of the present application are described in detail by taking the communication systems shown in FIG. 1 a and FIG. 1 b as examples. FIG. 1a and FIG. 1b are schematic diagrams of a wireless communication system applicable to the embodiments of the present application. As shown in FIG. 1a, the wireless communication system may include single or multiple network devices, or as shown in FIG. 1b, the communication system may include single or multiple terminal devices. A single network device can transmit data or control signaling to single or multiple terminal devices. Multiple network devices can also simultaneously transmit data or control signaling for a single terminal device. The wireless communication system can support coordinated multiple points transmission (CoMP), that is, multiple cells or multiple network devices can cooperatively participate in data transmission of a terminal device or jointly receive data sent by a terminal device, or multiple Each cell or multiple network devices performs coordinated scheduling or coordinated beamforming. The multiple cells may belong to the same network device or different network devices, and may be selected according to channel gain or path loss, received signal strength, received signal instruction, and the like.

It should be understood that the network device in the wireless communication system can be any device with a wireless transceiver function or a chip that can be provided in the device, and the device includes but is not limited to: base station, evolved node B (evolved node B, eNB) , home base station, access point (AP), wireless relay node, wireless backhaul node, transmission point (TP) or transmission point (transmission point) in wireless fidelity (wireless fidelity, WIFI) systems and reception point, TRP), etc., it can also be a gNB in the NR system, or it can also be a component or a part of equipment that constitutes a base station, such as a central unit (central unit, CU), a distributed unit (distributed unit, DU) or baseband Unit (baseband unit, BBU) and so on. It should be understood that, in the embodiments of the present application, the specific technology and specific device form adopted by the wireless access network device are not limited. In this application, wireless access network equipment is referred to as network equipment for short. Unless otherwise specified, in this application, network equipment refers to wireless access network equipment. In this application, the network device may refer to the network device itself, or may be a chip applied in the network device to complete the wireless communication processing function.

In some deployments, the gNB may include CUs and DUs. The gNB may also include a radio unit (RU). CU implements some functions of gNB, and DU implements some functions of gNB. For example, CU implements functions of radio resource control (RRC) and packet data convergence protocol (PDCP) layer, and DU implements wireless link. Control (radio link control, RLC), media access control (media access control, MAC) and physical (physical, PHY) layer functions. Since the information of the RRC layer will eventually become the information of the PHY layer, or be transformed from the information of the PHY layer, therefore, under this architecture, higher-layer signaling, such as RRC layer signaling or PHCP layer signaling, can also It is considered to be sent by DU, or, sent by DU+RU. It can be understood that the network device may be a CU node, a DU node, or a device including a CU node and a DU node. In addition, the CU may be divided into network equipment in the access network RAN, and the CU may also be divided into network equipment in the core network CN, which is not limited herein.

It should also be understood that the terminal equipment in the wireless communication system may also be referred to as a terminal, a user equipment (UE), a mobile station (MS), a mobile terminal (MT), and the like. The terminal device in the embodiment of the present application may be a mobile phone (mobile phone), a tablet computer (Pad), or a computer with a wireless transceiver function, and may also be applied to virtual reality (VR), augmented reality (AR) ), industrial control, self driving, remote medical, smart grid, transportation safety, smart city and smart home ) in scenarios such as wireless terminals. In this application, the aforementioned terminal devices and chips applicable to the aforementioned terminal devices are collectively referred to as terminal devices. It should be understood that the embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

It should be understood that FIG. 1a or FIG. 1b are only for the convenience of understanding, and schematically illustrate network equipment and terminal equipment, but this should not constitute any limitation to the present application, and the wireless communication system may also include more or less number of networks The device can also include a larger number of terminal devices. The network devices that communicate with different terminal devices can be the same network device or different network devices. The number of network devices that communicate with different terminal devices can be the same. It can also be different, and this application includes but is not limited to this.

For the communication system shown in FIG. 1a or FIG. 1b, the terminal device often needs to obtain absolute time information from the network device to synchronize the clock with the network device or to assist the global positioning system (Global Positioning System, GPS) to work. In this embodiment of the present application, the absolute time may include coordinated universal time (universal time coordinated, UTC), international atomic time (international atomic time, TAI), or GPS time. For example, in a 5G communication system, the network device can carry the absolute time information through a broadcast message system information block (SIB) 9, and send the absolute time information to the terminal device, or the network device can control the radio resource through a unicast message (radio resource control, RRC) signaling carries absolute time information, and the absolute time information is sent to the terminal device. At the same time, it is necessary to indicate the frame boundary corresponding to the absolute time information of the terminal device. The indication method may be to explicitly carry the frame identifier in the signaling or not to carry it explicitly. According to the protocol, a frame boundary or time window boundary is agreed.

After the terminal device receives the absolute time information sent by the network device, it adjusts its own clock according to the absolute time information and the frame boundary corresponding to the absolute time information, so that the absolute time between the terminal device and the network device at the same frame boundary is also the same. The purpose of clock synchronization.

Currently, architectures utilizing non-terrestrial network (NTN) for communication are under study. In the NTN network, there is also a network device that sends absolute time information to the terminal device to meet the synchronization requirements of the terminal device and the network device. However, in the NTN network, the distance between the network device and the terminal device is very long, so a large transmission delay will be introduced when the network device communicates with the terminal device. Usually, the transmission delay can be as high as several hundred milliseconds. , so after the terminal device receives the absolute time information sent by the network device, if it still only determines the absolute time corresponding to the terminal device at the specified frame boundary according to the received absolute time information, it will cause the terminal device to synchronize with the actual desired time. There is a large deviation between the effects. In order to clearly illustrate this problem, a detailed description is given below with reference to FIG. 2 and FIG. 3 .

As shown in Figure 2, it is a schematic diagram of system frame synchronization between the terminal equipment and the network equipment after the downlink synchronization of the 5G communication system.

When a terminal device accesses a 5G network, it generally first goes through processes such as cell search, acquisition of cell system information, and random access. During the cell search process, the network device sends a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and the terminal device detects the PSS or SSS signal to determine the position of subframe 0 in the system frame, Then, by receiving the cell system information, the system frame number is determined. The system frame number can also be called the system frame identifier. In this way, the terminal device completes the downlink synchronization with the network device, and determines and corresponds to the specific system frame and subframe of the network device. position and frame number. As shown in Figure 2, it is a schematic diagram of system frame and subframe synchronization between terminal equipment and network equipment after downlink synchronization of the 5G system. The essence of downlink synchronization is that after the terminal device receives the PSS or SSS signal and cell system information, it synchronizes its frame with the network device, that is, to ensure that the system frame where the network device sends the information is the same as the system frame where the terminal device receives the information. Synchronization of absolute time. After the terminal device completes the downlink synchronization, the terminal device and the network device will maintain a set of time represented by the system frame. Due to the existence of the propagation delay, in order to ensure that the system frame where the network device sends information and the system frame where the terminal device receives the information is the same , the absolute time corresponding to the system frame with the same frame number of the terminal device and the network device may be different. Therefore, in the present invention, the system frame of the network device refers to the system frame maintained by the network side, and the system frame of the terminal device refers to the system frame maintained by the terminal side. The system frames maintained by the network device and the terminal device may be the same set of system frames or different system frames.

As shown in FIG. 3 , it is a schematic diagram of the deviation between the absolute time sent by the network device and the absolute time determined by the terminal device.

For the convenience of description, it is assumed that the network device sends time information of an absolute time corresponding to the end boundary of the system frame 1. Specifically, the absolute time may be UTC time, TAI time or GPS time. The embodiments of the present application do not specific restrictions. Assuming that the transmission delay from the network device to the terminal device is the duration of one system frame, since the system frame alignment is performed in the process of downlink synchronization, the absolute time information corresponding to the end boundary of the system frame 1 of the network device is the same as that of the terminal device system. The absolute time information corresponding to the end boundary of frame 1 is inconsistent. It can be clearly seen from FIG. 3 that if the terminal device adjusts the absolute time corresponding to the end boundary of system frame 1 on the terminal device side according to the absolute time corresponding to the end boundary of system frame 1 indicated by the network device side, a large deviation will occur.

In view of the above problems, the embodiment of the present application provides a communication method, which enables the terminal device to obtain correct absolute time information in an NTN communication system or in a scenario where the transmission delay between other terminal devices and network devices cannot be ignored, thereby completing the Sync with network device is complete. The following will specifically introduce the communication method provided by the embodiment of the present application.

FIG. 4 is a schematic diagram of an embodiment of a communication method in an embodiment of the present application.

As shown in FIG. 4 , an embodiment of the communication method in the embodiment of the present application may include:

401. A terminal device acquires a first message.

Wherein, the first message carries one or more of first time information, an identifier of the first system frame, and transmission delay reference information, and the first time information is the time corresponding to the frame boundary of the first system. The terminal device may obtain the first message in different ways. For example, the terminal device may receive a broadcast message sent by the network device, or the terminal device may send a request message to the network device to request the network device to send the first message.

Specifically, the system frame boundary may be the start boundary or the end boundary of the system frame, or the start boundary or the end boundary of a time unit of other granularity.

The first message may be one message or multiple messages. That is, the first time information, the identifier of the first system frame, and the transmission delay reference information may be carried in the same message, or may be carried in different messages respectively, which will not be repeated below.

In a wireless communication system, after obtaining downlink synchronization with a cell through the cell search process, the terminal device also needs to obtain a series of system information (system information, SI), such as the network information of the cell where the terminal device is located, the information of the registration area, the public The information of the channel, and the information of other cells, etc., can work correctly in the cell. SIs are generally organized in a system information block (system information block, SIB for short) manner, wherein each SIB may contain a series of parameter sets related to a certain function.

According to the way network devices send system messages, system messages can be divided into two types: the first type is the SIB that all terminal devices in the cell need to acquire, and the second type is the SIB that some terminal devices in the cell need to acquire , while another part of the terminal equipment does not need the acquired SIB. In order to reduce the radio resource overhead caused by the transmission of the system message, the network side equipment may periodically broadcast and/or multicast to send the first type of SIB, so that the terminal equipment in the cell does not have to send the corresponding acquisition for this type of SIB. In addition, the network side device can unicast the second type of SIB according to the acquisition request of the terminal device, thereby avoiding the waste of radio resources caused by broadcasting and/or multicasting the second type of SIB.

For example, in the NR system, the SIB9 includes time information related to GPS or UTC or other types of time information, which is used to help the terminal device obtain the absolute time information of the network device. In this embodiment of the present application, the network device may periodically broadcast and/or multicast to send the SIB9 to the terminal device, or the network device may actively use a unicast message radio resource control (radio resource control, based on the request of the terminal device or not based on the request) RRC) signaling sends absolute time information to the terminal device. The SIB9 message or unicast RRC signaling may include the first system frame, the second system frame or the third system frame. The first, second and third system frames do not represent restrictions on the number of system frames, but are only to distinguish different system frame. In the embodiment of the present application, the SIB9 message or the unicast RRC signaling may carry an identifier of a system frame, for example, may carry the identifier of the first system frame, and indicate the absolute time corresponding to the boundary of the first system frame. It should be noted that in the present invention, the relative time is not limited to the system frame boundary, and the system frame boundary can also be replaced by a subframe boundary or a relative time unit boundary with a smaller time granularity, which will not be repeated below.

In this embodiment of the present application, the first message also carries transmission delay reference information. The transmission delay reference information may specifically be the location information of the network device, the transmission power of the network device, or the preset transmission delay, or information that may be used by other terminal devices to determine the transmission delay between the terminal device and the network device. The transmission delay reference information is used for indicating the second time or for the terminal device to determine the second time.

402. The terminal device determines the second time according to the first time information and the transmission delay reference information.

After the terminal device completes the downlink synchronization with the network device, it determines and corresponds to the specific system frame and system frame number of the network device. The specific process of frame alignment of the downlink synchronization system can be understood by referring to the description of FIG. 2 , and details are not repeated here.

In a specific implementation manner, the frame number of the second system frame may be the same as the frame number of the first system frame. For example, after the terminal device completes downlink synchronization with the network device, the first system frame corresponds to the second system frame. Assuming that the propagation delay between the terminal device and the network device determined by the terminal device according to the transmission delay reference information is t1, and assuming that the time corresponding to the frame boundary of the first system is T1, the second time can be T1+t1, and the second time is the moment corresponding to the frame boundary of the second system of the terminal device, and the frame number of the second system frame is the same as the frame number of the first system frame.

In a specific embodiment, the frame number of the second system frame is different from that of the first system frame. For example, it is assumed that the transmission delay reference information is a preset time, the preset time is stored in the network device in advance, and the preset time is the estimated transmission delay between the network device and the terminal device. Assuming that the preset time is the duration of one system frame, if the network device sends time information of an absolute time corresponding to the end boundary of system frame 1 . Then, the terminal device adjusts the absolute time corresponding to the end boundary of system frame 2 on the terminal device side according to the absolute time corresponding to the end boundary of system frame 1 indicated by the network device side. At this time, after the terminal device completes the downlink synchronization with the network device, the system frame 1 on the network device side corresponds to the system frame 1 on the terminal device side, and the system frame 2 on the terminal device side corresponds to the frame number of the second system frame, and the system frame 1 is equivalent to the frame number of the first system frame, and the frame number of the second system frame is different from the frame number of the first system frame.

It can be seen from the embodiment corresponding to FIG. 4 that the terminal device can determine the time corresponding to the second system frame boundary of the terminal device according to the first time information and the transmission delay reference information, so that the terminal device can obtain a more accurate absolute time, and then completes the process. Synchronization with network devices to improve synchronization accuracy. In different embodiments, the terminal device may also obtain more accurate absolute time according to other methods. In addition, it can be seen from the embodiment corresponding to FIG. 4 that in different embodiments, the transmission delay reference information may be different information. The following will describe in detail other methods for obtaining more accurate absolute time and transmission delay reference information. instruction of.

FIG. 5 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application.

As shown in FIG. 5 , another embodiment of the communication method in the embodiment of the present application may include:

501. A terminal device acquires a first system message.

The first system message carries second time information and transmission delay reference information. The terminal device can obtain the first system message in different ways. For example, the terminal device can receive a broadcast message sent by the network device, or the terminal device can send a request message to the network device to request the network device to send the first system message.

In a specific implementation manner, the second time information is the time corresponding to the boundary of the first time window for sending the first system message. In order to ensure that the terminal device can correctly receive the SIB message, a system information window (SI-window) is defined. window is a fixed duration. In this embodiment of the present application, different SIs may be mapped to the same SI-window or to different SI-windows, and the SI-windows corresponding to different SIs may overlap (specifically, some time-frequency resources overlap), or may not overlapping. The terminal device needs to monitor the starting position of the SI-window until the SIB message in the SI is successfully received.

For example, in the NR system, the SIB9 includes time information related to GPS or UTC or other types of time information, which is used to help the terminal device obtain the absolute time information of the network device. In this embodiment of the present application, the network device may periodically broadcast and/or multicast to send the SIB9 to the terminal device, or the network device may send the SIB9 to the terminal device based on a request of the terminal device. Assuming that the SI-window corresponding to the SIB9 message is the fifth system frame to the tenth system frame, the boundary of the fifth system frame can be regarded as the starting boundary of the SI-window, and the boundary of the tenth system frame can be regarded as It is the end boundary of the SI-window. The terminal device needs to monitor the start position of the SI-window until the end of the SI-window, so the terminal device can obtain the time corresponding to the start boundary of the SI-window or the time corresponding to the end boundary of the SI-window. In this embodiment, it is assumed that the boundary of the SI-window is just aligned with a certain system frame boundary; it is assumed that the boundary of the SI-window is not aligned with any system frame boundary, which corresponds to the following embodiment.

In a specific embodiment, or the second time information is the time corresponding to the third system frame boundary, wherein the third system frame boundary is the nearest system frame boundary after the first time window boundary in which the first system message is sent.

Assuming that the SI-window corresponding to the SIB9 message is the second subframe of the first system frame to the fifth subframe of the second system frame, the boundary of the SI-window is not aligned with the boundary of any system frame. At this time The second time information is the time corresponding to the nearest system frame boundary after the end boundary of the SI-window (ie, the end boundary of the second system frame). The second time information can also be the time corresponding to the nearest system frame boundary after the start boundary of the SI-window (that is, the end boundary of the first system frame); or the nearest system frame boundary before the start boundary of the SI-window (that is, the first system frame boundary The time corresponding to the start boundary of the system frame No. 1). The terminal device needs to monitor the start position of the SI-window until the end of the SI-window, so the terminal device can obtain the position of the start boundary or the end boundary of the SI-window in the time domain.

In this embodiment of the present application, the first system message also carries transmission delay reference information. The transmission delay reference information may specifically be the location information of the network device or the transmission power of the network device, or information that may be used by other terminal devices to determine the transmission delay between the terminal device and the network device. The transmission delay reference information is used to indicate the third moment or for the terminal device to determine the third moment.

502. The terminal device determines a third time point according to the second time information and the transmission delay reference information.

The third time is the time corresponding to the boundary of the second time window for receiving the first system message.

In a specific implementation, it is assumed that the propagation delay between the terminal device and the network device determined by the terminal device according to the transmission delay reference information is t2, and the time corresponding to the end boundary of the SI-window for sending the first system message is assumed to be T2, the third time may be T2+t2, and the third time is the time corresponding to the end boundary of the SI-window receiving the first system message. Or suppose that the time corresponding to the start boundary of the SI-window for sending the first system message is T3, then the third time may be T3+t2, and the third time corresponds to the start boundary of the SI-window for receiving the first system message. time.

In a specific implementation, it is assumed that the propagation delay between the terminal device and the network device determined by the terminal device according to the transmission delay reference information is t2, and it is assumed that the nearest system frame boundary after the SI-window boundary of the first system message is sent The corresponding time is T2, then the third time may be T2+t2, and the third time is the time corresponding to the nearest system frame boundary after the boundary of the SI-window in which the first system message is received. The SI-window boundary can be a start boundary or an end boundary.

It can be seen from the embodiment corresponding to FIG. 5 that the terminal device can determine the time corresponding to the boundary of the SI-window according to the second time information and the transmission delay reference information, so that the terminal device can obtain a more accurate absolute time, and then complete the communication with the network. Synchronization of devices to improve synchronization accuracy.

It can be seen from the above-mentioned embodiments corresponding to FIG. 4 and FIG. 5 that the transmission delay reference information may be different information. In the following, the transmission delay reference information is the location information of the network device, and the transmission delay reference information is the network device and the first one. The second transmission delay between locations, the reference information of the transmission delay is the transmission power of the network device, which will be described in detail.

FIG. 6 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application.

As shown in FIG. 6 , another embodiment of the communication method in the embodiment of the present application may include:

601. The terminal device acquires location information and time information of the network device.

In a specific embodiment, the terminal device acquires the location information and time information of the network device by acquiring the first message, where the first message carries the location information, the first time information, and the identifier of the first system frame of the network device. The first message can be understood by referring to the first message described in the embodiment corresponding to FIG. 4 , and details are not repeated here.

In a specific implementation manner, the terminal device acquires the location information and time information of the network device by acquiring the first system message, where the first message carries the location information and the second time information of the network device. The first system message can be understood by referring to the first system message described in the embodiment corresponding to FIG. 5 , and details are not repeated here.

602. The terminal device determines a first transmission delay between the network device and the terminal device according to the location information of the network device and the location information of the terminal device.

If the terminal device is configured with a positioning device, for example, the terminal device is configured with GPS, etc., the terminal device can learn its own location information. According to the location information of the network device and the terminal device, the terminal device can know the distance d between the network device and the terminal device. The ratio of the distance d to the speed of light c is the first transmission delay t3, that is, t=d/c.

In a specific embodiment, the network device includes a satellite and a base station, as shown in FIG. 7 , where the base station may be located on the satellite. The satellites can be satellites in the BeiDou navigation satellite system (BDS), satellites in GPS, or satellites in the GLONASS satellite navigation system (global navigation satellite system, GLONASS). The embodiment is not limited. In the communication system shown in FIG. 7, the first transmission delay t3=(satellite GPS position-terminal device GPS position)/light speed, where (satellite GPS position-terminal device GPS position) represents the space from the satellite/base station to the terminal device distance value.

In a specific implementation manner, the network device includes a satellite and a base station, as shown in FIG. 8 , wherein the communication signal is sent by the base station and then forwarded to the terminal device through the satellite. The first transmission delay t3=(satellite GPS position-terminal device GPS position)/speed of light+(satellite GPS position-base station GPS position)/light speed, where (satellite GPS position-terminal device GPS position) indicates that the satellite reaches the terminal device in space The distance value on the (satellite GPS position - the base station GPS position) represents the distance value from the satellite to the base station in space.

603. The terminal device determines the second time according to the first time information and the first transmission delay.

After the terminal device completes the downlink synchronization with the network device, it determines and corresponds to the specific system frame and system frame number of the network device. The specific process of frame alignment of the downlink synchronization system can be understood by referring to the description of FIG. 2 , and details are not repeated here. In this embodiment of the present application, after the terminal device completes downlink synchronization with the network device, the first system frame corresponds to the second system frame, in other words, the first system frame and the second system frame are aligned, and the first system frame and the second system frame are aligned. The frame numbers of the second system frames are the same.

The terminal device determines the first transmission delay t3 between the network device and the terminal device according to the location information of the network device and the location information of the terminal device. Assuming that the time corresponding to the frame boundary of the first system is T1, the second time can be T1+ t3, the second time is the time corresponding to the second system frame boundary of the terminal device.

In a specific implementation manner, it may further include 604. The terminal device determines the third time point according to the second time information and the first transmission delay. Assuming that the time corresponding to the end boundary of the SI-window that sends the first system message is T2, the third time can be T2 + the first transmission delay, and the third time corresponds to the end boundary of the SI-window that receives the first system message time. Or suppose that the time corresponding to the start boundary of the SI-window that sends the first system message is T3, then the third time can be T2 + the first transmission delay, and the third time is the start of the SI-window that receives the first system message The moment corresponding to the boundary.

In a specific implementation manner, steps 602 and 603 may be executed in combination, that is, the terminal device determines the second time according to the location information of the network device, the location information of the terminal device, and the first time information. Taking the communication system described in FIG. 8 as an example, the second time = time T1 corresponding to the frame boundary of the first system + (satellite GPS position - terminal device GPS position)/light speed + (satellite GPS position - base station GPS position)/light speed, Wherein (satellite GPS position - terminal device GPS position) represents the spatial distance value from the satellite to the terminal device, and (satellite GPS position - base station GPS position) represents the spatial distance value from the satellite to the base station.

In a specific implementation manner, steps 602 and 604 may be performed in combination, that is, the terminal device determines the third time according to the location information of the network device, the location information of the terminal device, and the second time information. By way of example, taking the communication system described in FIG. 8 as an example, the third moment=the moment corresponding to the end boundary of the SI-window that sends the first system message is T2+(satellite GPS position-terminal device GPS position)/light speed+( Satellite GPS position - base station GPS position)/light speed or third time = time corresponding to the nearest system frame boundary after the SI-window boundary of sending the first system message + (satellite GPS position - terminal device GPS position)/light speed + ( Satellite GPS position - base station GPS position)/speed of light, where (satellite GPS position - terminal device GPS position) represents the distance value from the satellite to the terminal device in space, (satellite GPS position - base station GPS position) represents the space from the satellite to the base station distance value.

It should be noted that, 603 and 604 in the embodiment corresponding to FIG. 6 may be executed alternatively in the actual application process. In addition, it should be noted that the embodiment corresponding to FIG. 6 may be combined with any one of the embodiments corresponding to FIG. 4 and FIG. 5 or executed independently. The location information of the network device in the embodiment corresponding to FIG. 6 may refer to the transmission delay reference information in the embodiment corresponding to FIG. 4 or FIG. 5 , and the time information of the network device in the embodiment corresponding to FIG. 6 may refer to FIG. The first time information in the embodiment corresponding to 4 or the second time information in the embodiment corresponding to FIG. 5 . When the embodiment corresponding to FIG. 6 is executed in combination with the embodiment corresponding to FIG. 4 or FIG. 5 , the explanation and definition of the features in the embodiment corresponding to FIG. 6 may refer to the embodiment corresponding to FIG. 4 or FIG. 5 .

It can be seen from the embodiment corresponding to FIG. 6 that the terminal device can determine the first transmission delay between the network device and the terminal device according to the location information of the network device and the location information of the terminal device, and the absolute time sent by the network device is combined with the first transmission delay. The delay allows the terminal device to obtain a more accurate absolute time, thereby completing the synchronization with the network device and improving the synchronization accuracy.

FIG. 9 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application.

As shown in FIG. 9, another embodiment of the communication method in the embodiment of the present application may include:

901. The terminal device acquires the second transmission delay between the network device and the first location and the time information of the network device.

The first position is a preset or defined position or the first position is a reference position. For example, the first location may be a fixed location on the ground, the location of a fixed lighthouse, the center of a cell, or a landmark location, and so on.

In a specific implementation manner, the terminal device acquires the second transmission delay by acquiring the first message, where the first message carries the second transmission delay, the first time information, and the identifier of the first system frame. The first message can be understood by referring to the first message described in the embodiment corresponding to FIG. 4 , and details are not repeated here.

In a specific implementation manner, the terminal device acquires the second transmission delay by acquiring the first system message, where the first system message carries the second transmission delay and the second time information. The first system message can be understood by referring to the first system message described in the embodiment corresponding to FIG. 5 , and details are not repeated here.

In a specific embodiment, the network device includes a satellite and a base station, as shown in FIG. 7 , wherein the base station is integrated on the satellite. In the communication system shown in FIG. 7, the second transmission delay t4=(satellite GPS position-first position)/speed of light, wherein (satellite GPS position-first position) represents the space from the satellite/base station to the first position distance value.

In a specific implementation manner, the network device includes a satellite and a base station, as shown in FIG. 8 , wherein the communication signal is sent by the base station and then forwarded to the terminal device through the satellite. The second transmission delay t4=(satellite GPS position-first position)/speed of light+(satellite GPS position-base station GPS position)/light speed, where (satellite GPS position-first position) indicates that the satellite reaches the first position in space The distance value of (satellite GPS position - base station GPS position) represents the distance value from the satellite to the base station in space.

902. The terminal device determines a third transmission delay between the terminal device and the first location.

903. The terminal device determines the second time according to the first time information, the second transmission delay, and the third transmission delay.

After the terminal device completes the downlink synchronization with the network device, it determines and corresponds to the specific system frame and system frame number of the network device. The specific process of frame alignment of the downlink synchronization system can be understood by referring to the description of FIG. 2 , and details are not repeated here. In this embodiment of the present application, after the terminal device completes downlink synchronization with the network device, the first system frame corresponds to the second system frame, in other words, the first system frame and the second system frame are aligned, and the first system frame and the second system frame are aligned. The frame numbers of the second system frames are the same.

Assuming that the time corresponding to the frame boundary of the first system is T1, the second time may be T1+second propagation delay t4+third propagation delay t5, and the second time is the time corresponding to the second system frame boundary of the terminal device.

In a specific embodiment, it may further include 904. The terminal device determines the third time point according to the first time information, the second transmission delay and the third transmission delay. Assuming that the time corresponding to the end boundary of the SI-window for sending the first system message is T2, the third time can be T2 + the second transmission delay + the third transmission delay, and the third time is the SI-window that receives the first system message The moment corresponding to the end boundary of the window. Or suppose that the time corresponding to the start boundary of the SI-window for sending the first system message is T3, then the third time may be T2 + the second transmission delay + the third transmission delay, and the third time is the time when the first system message is received. The time corresponding to the start boundary of the SI-window.

In a specific implementation manner, step 902 and step 903 may be performed in combination, that is, the terminal device determines the second time according to the third transmission delay, the second transmission delay and the first time information. Taking the communication system described in FIG. 8 as an example, the second time = time T1 corresponding to the frame boundary of the first system + (satellite GPS position - first position)/light speed + (satellite GPS position - base station GPS position)/light speed + ( First position - terminal device GPS position)/speed of light, where (satellite GPS position - first position) represents the distance value from the satellite to the first position in space, (satellite GPS position - base station GPS position) represents the space between the satellite and the base station The distance value on , (the first position - the GPS position of the terminal device) represents the distance value of the terminal device to the first position in space.

In a specific implementation manner, step 902 and step 904 may be performed in combination, that is, the terminal device determines the third time according to the location information of the network device, the location information of the terminal device, and the second time information. By way of example, taking the communication system described in FIG. 8 as an example, the third moment = the moment corresponding to the end boundary of the SI-window that sends the first system message is T2 + (satellite GPS position - first position)/speed of light + (satellite GPS position - GPS position of base station) / speed of light + (first position - GPS position of terminal device) / speed of light or third time = time corresponding to the nearest system frame boundary after the boundary of the SI-window in which the first system message was sent + (satellite GPS position - first position)/speed of light + (satellite GPS position - base station GPS position)/light speed + (first position - terminal device GPS position)/light speed, where (satellite GPS position - first position) means that the satellite reaches the first position The distance value of the position in space, (satellite GPS position - base station GPS position) represents the distance value from the satellite to the base station in space, (first position - terminal device GPS position) represents the spatial distance from the terminal device to the first position value.

It should be noted that, 903 and 904 in the embodiment corresponding to FIG. 9 may be executed alternatively in the actual application process. In addition, it should be noted that the embodiment corresponding to FIG. 9 may be combined with any one of the embodiments corresponding to FIG. 4 and FIG. 5 or executed independently. The second transmission delay in the embodiment corresponding to FIG. 9 may refer to the transmission delay reference information in the embodiment corresponding to FIG. 4 or FIG. 5 , and the time information of the network device in the embodiment corresponding to FIG. 9 may refer to FIG. The first time information in the embodiment corresponding to 4 or the second time information in the embodiment corresponding to FIG. 5 . When the embodiment corresponding to FIG. 6 is executed in combination with the embodiment corresponding to FIG. 4 or FIG. 5 , the explanation and definition of the features in the embodiment corresponding to FIG. 6 may refer to the embodiment corresponding to FIG. 4 or FIG. 5 .

It can be seen from the embodiment corresponding to FIG. 9 that the absolute time sent by the network device is combined with the second transmission delay and the third transmission delay, so that the terminal device can obtain a more accurate absolute time, thereby completing the synchronization with the network device, improving the performance of the terminal device. Accuracy of synchronization.

FIG. 10 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application.

As shown in FIG. 10 , another embodiment of the communication method in this embodiment of the present application may include:

1001. The terminal device receives the transmission power of the network device and the time information of the network device.

In a specific embodiment, the terminal device obtains the transmission power and time information of the network device through a first message, where the first message carries the transmission power of the network device, the first time information, and the identifier of the first system frame. The first message can be understood by referring to the first message described in the embodiment corresponding to FIG. 4 , and details are not repeated here.

In a specific implementation manner, the terminal device acquires the transmission power and time information of the network device by acquiring the first system message, where the first system message carries the transmission power and the second time information of the network device. The first system message can be understood by referring to the first system message described in the embodiment corresponding to FIG. 5 , and details are not repeated here.

1002. The terminal device determines the path power loss according to the transmit power of the network device.

Path power loss may also be referred to simply as path loss or pathloss. The path loss is the difference between the transmit power of the network device and the receive power of the terminal device, that is, path loss=transmit power-receive power.

1003. The terminal device determines a fourth transmission delay from the network device to the terminal device according to the path power loss.

The terminal device may determine the fourth transmission delay from the network device to the terminal device according to the path loss and some other parameters. For example, in a specific implementation manner, the terminal device determines the fourth transmission delay according to the path power loss combined with the information transmission frequency, Or, in a specific implementation manner, the terminal device determines the fourth transmission delay according to the path power loss combined with the information transmission speed, or in a specific implementation manner, the terminal device determines the information transmission frequency and information transmission speed based on the path power loss combined with the information transmission speed A fourth transmission delay is determined. For example, assuming that the wireless transmission distance, the frequency and path loss used in wireless transmission satisfy a certain equation relationship or formula, the path loss can be determined according to known parameters. As an example, assuming the equation relationship is: path loss=20lgd+20lgf+X, where X is a constant, the path loss can be based on the known parameters of the wireless transmission distance d, the frequency f used for wireless transmission and a known constant X is OK. It should be noted that the above equation is only an example, and the present invention does not limit the path loss to be determined according to the above equation.

1004. The terminal device determines the second time according to the first time information and the fourth transmission delay.

After the terminal device completes the downlink synchronization with the network device, it determines and corresponds to the specific system frame and system frame number of the network device. The specific process of frame alignment of the downlink synchronization system can be understood by referring to the description of FIG. 2 , and details are not repeated here. In this embodiment of the present application, after the terminal device completes downlink synchronization with the network device, the first system frame corresponds to the second system frame, in other words, the first system frame and the second system frame are aligned, and the first system frame and the second system frame are aligned. The frame numbers of the second system frames are the same.

Assuming that the time corresponding to the frame boundary of the first system is T1, the second time may be T1 + the fourth transmission delay, and the second time is the time corresponding to the frame boundary of the second system of the terminal device.

In a specific embodiment, it may further include 1005. The terminal device determines the third time point according to the second time information and the fourth transmission delay. Assuming that the time corresponding to the end boundary of the SI-window for sending the first system message is T2, the third time may be T2 + the fourth transmission delay, and the third time corresponds to the end boundary of the SI-window for receiving the first system message time. Or suppose that the time corresponding to the start boundary of the SI-window that sends the first system message is T3, then the third time can be T2 + the fourth transmission delay, and the third time is the start of the SI-window that receives the first system message The moment corresponding to the boundary.

In a specific implementation manner, steps 1002 to 1004 can be performed in combination, that is, the terminal device determines the second moment according to transmit power, receive power, and some other parameters as well as the first time information, and some other parameters may include transmission frequency or transmission frequency. speed.

In a specific implementation manner, steps 1002 to 1003 and step 1005 can be performed in combination, that is, the terminal device determines the third moment according to transmit power, receive power, and some other parameters as well as the second time information, and some other parameters may include transmission frequency or transmission speed.

It should be noted that, 1004 and 1005 in the embodiment corresponding to FIG. 10 may be executed alternatively in the actual application process.

In addition, it should be noted that the embodiment corresponding to FIG. 10 may be combined with any one of the embodiments corresponding to FIG. 4 and FIG. 5 or independently executed. The transmission power of the network device in the embodiment corresponding to FIG. 10 may refer to the transmission delay reference information in the embodiment corresponding to FIG. 4 or FIG. 5 , and the time information of the network device in the embodiment corresponding to FIG. 10 may refer to FIG. The first time information in the embodiment corresponding to 4 or the second time information in the embodiment corresponding to FIG. 5 . When the embodiment corresponding to FIG. 10 is executed in combination with the embodiment corresponding to FIG. 4 or FIG. 5 , the explanation and definition of the features in the embodiment corresponding to FIG. 10 may refer to the embodiment corresponding to FIG. 4 or FIG. 5 .

It can be seen from the embodiment corresponding to FIG. 10 that the terminal device can determine the fourth transmission delay between the network device and the terminal device according to the path loss power, and the absolute time sent by the network device is combined with the fourth transmission delay, so that the terminal device can obtain More accurate absolute time, and then complete the synchronization with the network equipment, and improve the synchronization accuracy.

FIG. 11 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application.

As shown in FIG. 11 , another embodiment of the communication method in this embodiment of the present application may include:

1101. A terminal device acquires a first message.

The first message carries the first time information and the identifier of the first system frame, and the first time information is the time corresponding to the boundary of the first system frame.

The terminal device may obtain the first message in different ways. For example, the terminal device may receive a broadcast message sent by the network device, or the terminal device may send a request message to the network device to request the network device to send the first message.

For example, in the NR system, the SIB9 includes time information related to GPS or UTC or other types of time information, which is used to help the terminal device obtain the absolute time information of the network device. In this embodiment of the present application, the network device may periodically broadcast and/or multicast to send the SIB9 to the terminal device, or the network device may actively use a unicast message radio resource control (radio resource control, based on the request of the terminal device or not based on the request) RRC) signaling sends absolute time information to the terminal device. The SIB9 message or unicast RRC signaling may include the first system frame, the second system frame or the third system frame. The first, second and third system frames do not represent restrictions on the number of system frames, but are only to distinguish different system frame. In the embodiment of the present application, the SIB9 message or the unicast RRC signaling may carry an identifier of a system frame, for example, may carry the identifier of the first system frame, and indicate the absolute time corresponding to the boundary of the first system frame.

1102. The terminal device determines the second time according to the first time information and a timing advance (time advance, TA).

In a wireless communication system, in order to ensure the orthogonality of uplink transmission and avoid intra-cell interference, it is required that the times of the uplink signals from different terminal devices arriving at the network device are basically aligned. Therefore, the network device sends a TA to the terminal device, and the terminal device adjusts the time for sending the uplink signal according to the received TA, thereby realizing uplink timing synchronization between the terminal device and the network device. Usually the time advance is twice the amount of transmission time, which is also referred to as round trip time (RTT).

The network device estimates the TA according to the random access preamble, and sends msg2 to the terminal device, where the msg2 carries the TA. Of course, the terminal device can also obtain the TA in other ways. The embodiments of the present application do not limit the way the terminal device obtains the TA. For example, the network device can determine the TA value of each terminal device based on measuring the uplink transmission of the corresponding terminal device. Therefore, as long as the terminal device has uplink transmission, the network device can use it to estimate the TA value and send it to the terminal device through a downlink message.

Assuming that the time corresponding to the frame boundary of the first system is T1, the second time may be T1+TA/2, and the second time is the time corresponding to the frame boundary of the second system of the terminal device. The frame identifiers of the first system frame and the second system frame are the same.

In a specific implementation manner, the method may further include 1103. The terminal device determines that the first timer has not timed out.

When the terminal device is in the idle state, the TA is the TA that was maintained in the connected state before the last terminal device transferred to the idle state, and the first timer is started when the terminal device transfers from the connected state to the idle state, and the first timer runs During the process, the terminal device considers that the TA is valid and can be used. When the first timer expires, the terminal device considers that the TA is invalid and cannot be used. The first timer duration T is configured by the network device; or the first timer duration T is determined by the terminal device according to the movement state, where the movement state may include the movement speed of the terminal device. For example, if the terminal device determines the current movement If the speed is v1, the terminal device may configure the duration T of the first timer as T2. If the terminal device determines that the current moving speed is v2, where v2 is greater than v1, the terminal device may configure the duration T of the first timer as T3 , where T3 is less than T2; or the duration T is determined by the terminal device according to the mobile state and the configuration of the network device. For example, the duration of the first timer configured by the network device is T3, then the terminal device can be based on T3. state, for example, configure the duration of the first timer as T4 according to its own moving speed, where T4 may be greater than T3 or T4 may be less than T3.

It can be seen from the embodiment corresponding to FIG. 11 that the terminal device can combine the TA with the absolute time sent by the network device, so that the terminal device can obtain a more accurate absolute time, thereby completing the synchronization with the network device and improving the synchronization accuracy.

FIG. 12 is a schematic diagram of another embodiment of the communication method in the embodiment of the present application.

As shown in FIG. 12 , another embodiment of the communication method in this embodiment of the present application may include:

1201. A terminal device acquires a first system message.

The first system message carries second time information, where the second time information is a time corresponding to a time window boundary for sending the first system message.

The terminal device can obtain the first system message in different ways. For example, the terminal device can receive a broadcast message sent by the network device, or the terminal device can send a request message to the network device to request the network device to send the first system message. The second time information is the time corresponding to the boundary of the first time window for sending the first system message.

For example, in an NR system, SIB9 provides system time information. In this embodiment of the present application, the network device may periodically broadcast and/or multicast the SIB9, or the network device may send the SIB9 to the terminal device through a unicast message RRC signaling based on the request of the terminal device. Assuming that the SI-window corresponding to SIB9 is the fifth system frame to the tenth system frame, the boundary of the fifth system frame can be regarded as the starting boundary of the SI-window, and the boundary of the tenth system frame can be regarded as The end boundary of the SI-window. The terminal device needs to monitor the start position of the SI-window until the SIB message in the SI is successfully received, so the terminal device can obtain the time corresponding to the start boundary of the SI-window or the time corresponding to the end boundary of the SI-window.

1202. The terminal device determines a third time according to the second time information and a timing advance (time advance, TA).

Assuming that the time corresponding to the end boundary of the SI-window that sends the first system message is T2, the third time can be T2+TA/2, and the third time is the time corresponding to the end boundary of the SI-window that receives the first system message . Or suppose that the time corresponding to the start boundary of the SI-window that sends the first system message is T3, then the third time can be T3+TA/2, and the third time is the start boundary of the SI-window that receives the first system message corresponding moment.

In a specific implementation manner, the method may further include 1203. The terminal device determines that the first timer has not timed out.

When the terminal device is in the idle state, the TA is the TA that was maintained in the connected state before the last terminal device transferred to the idle state, and the first timer is started when the terminal device transfers from the connected state to the idle state, and the first timer runs During the process, the terminal device considers that the TA is valid and can be used. When the first timer expires, the terminal device considers that the TA is invalid and cannot be used. The first timer duration T is configured by the network device; or the first timer duration T is determined by the terminal device according to the movement state, where the movement state may include the movement speed of the terminal device. For example, if the terminal device determines the current movement If the speed is v1, the terminal device may configure the duration T of the first timer as T2. If the terminal device determines that the current moving speed is v2, where v2 is greater than v1, the terminal device may configure the duration T of the first timer as T3 , where T3 is less than T2; or the duration T is determined by the terminal device according to the mobile state and the configuration of the network device. For example, the duration of the first timer configured by the network device is T3, then the terminal device can be based on T3. state, for example, configure the duration of the first timer as T4 according to its own moving speed or moving direction or moving route, where T4 may be greater than T3 or T4 may be less than T3.

It can be seen from the embodiment corresponding to FIG. 12 that the terminal device can combine the TA with the absolute time sent by the network device, so that the terminal device can obtain a more accurate absolute time, thereby completing the synchronization with the network device and improving the synchronization accuracy.

The foregoing mainly introduces the solutions provided by the embodiments of the present application from the perspective of interaction between a network device and a terminal device. It can be understood that, in order to realize the above-mentioned functions, the above-mentioned network equipment and terminal equipment include corresponding hardware structures and/or software modules for performing each function. Those skilled in the art should easily realize that the present application can be implemented in hardware or in the form of a combination of hardware and computer software. Whether a function is performed by hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Describing from the hardware structure, the terminal device and the network device in FIG. 4 to FIG. 12 can be implemented by one entity device, or can be implemented jointly by multiple entity devices, and can also be a logic function module in one entity device. This application The embodiment does not specifically limit this.

For example, the terminal device may be implemented by the communication device in FIG. 13 . FIG. 13 is a schematic diagram of a hardware structure of a communication device provided by an embodiment of the present application. It includes: a communication interface 1301 and a processor 1302, and may also include a memory 1303.

The communication interface 1301 may use any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), and the like.

The processor 1302 includes, but is not limited to, a central processing unit (CPU), a network processor (NP), an application-specific integrated circuit (ASIC), or a programmable logic device (PLD). ) one or more of. The above-mentioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof. Processor 1302 is responsible for communication lines 1304 and general processing, and may also provide various functions including timing, peripheral interface, voltage regulation, power management, and other control functions. Memory 1303 may be used to store data used by processor 1302 in performing operations.

Memory 1303 may be read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM), or other types of information and instructions The dynamic storage device can also be an electrically erasable programmable read-only memory (electrically programmable read-only memory, EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, Optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or capable of carrying or storing desired program code in the form of instructions or data structures and capable of Any other medium that can be accessed by a computer, but is not limited to this. The memory may exist independently and be connected to the processor 1302 through the communication line 1304 . The memory 1303 may also be integrated with the processor 1302. If the memory 1303 and the processor 1302 are separate devices, the memory 1303 and the processor 1302 are connected, for example, the memory 1303 and the processor 1302 can communicate through a communication line. The communication interface 1301 and the processor 1302 can communicate through a communication line, and the communication interface 1301 can also be directly connected to the processor 1302 .

Communication lines 1304 , which may include any number of interconnected buses and bridges, link together various circuits including one or more processors 1302 , represented by processor 1302 , and memory, represented by memory 1303 . Communication lines 1304 may also link together various other circuits, such as peripherals, voltage regulators, and power management circuits, etc., which are well known in the art and, therefore, will not be described further herein.

In a specific implementation manner, the terminal device may include: a memory for storing computer-readable instructions. It also includes a communication interface coupled with the memory for acquiring a first message, where the first message carries first time information, an identifier of the first system frame and transmission delay reference information, and the first time information is the frame boundary of the first system corresponding moment.

Also included: a processor coupled with the communication interface for executing computer readable instructions in the memory to perform the following operations:

The second time is determined according to the first time information and the transmission delay reference information, where the second time is the time corresponding to the second system frame boundary of the terminal device, and the frame identifiers of the first system frame and the second system frame are the same.

In a specific implementation manner, the transmission delay reference information is location information of the network device.

The processor is specifically configured to determine the second time according to the first time information and the first transmission delay. The first transmission delay is determined according to the location information of the network device and the location information of the terminal device.

In a specific embodiment, the transmission delay reference information is the second transmission delay between the network device and the first location.

The processor is specifically configured to determine the second moment according to the first time information, the second transmission delay, and the third transmission delay. The third transmission delay is determined according to the terminal device and the first location.

In a specific implementation, the transmission delay reference information is the transmission power of the network device.

The processor is specifically configured to determine the second moment according to the first time information and the fourth transmission delay. The fourth transmission delay is the transmission delay between the network device and the terminal device determined according to the path loss, and the path power loss is determined according to the transmit power of the network device.

In a specific embodiment, the fourth transmission delay is determined according to one or more of path power loss, information transmission frequency and information transmission speed, and the path power loss is determined according to the transmission power of the network device and the reception of the terminal device. power is determined.

In a specific embodiment, the terminal device includes: a memory for storing computer-readable instructions.

It also includes a communication interface coupled with the memory for acquiring a first message, where the first message carries first time information and an identifier of the first system frame, and the first time information is the time corresponding to the boundary of the first system frame.

Also included: a processor coupled with the communication interface for executing computer readable instructions in the memory to perform the following operations:

The second time is determined according to the first time information and the timing advance amount TA, the second time is the time corresponding to the second system frame boundary of the terminal device, and the frame identifiers of the first system frame and the second system frame are the same.

In the terminal device, wherein: TA corresponds to a first timer, and the duration of the first timer is T.

The processor is further configured to determine that the first timer has not timed out.

The terminal device duration T is configured by the network device. Or the duration T is determined by the terminal device according to the movement state. Alternatively, the duration T is determined by the terminal device according to the movement state and the configuration of the network device.

In the embodiments of the present application, the communication interface may be regarded as a transceiver unit of the terminal device, the processor with processing function may be regarded as the processing unit of the terminal device, and the memory may be regarded as the storage unit of the terminal device. As shown in FIG. 14 , the terminal device includes a transceiver unit 1410 and a processing unit 1420 . The transceiving unit may also be referred to as a transceiver, a transceiver, a transceiving device, or the like. The processing unit may also be referred to as a processor, a processing single board, a processing module, a processing device, and the like. Optionally, the device for implementing the receiving function in the transceiver unit 1410 may be regarded as a receiving unit, and the device for implementing the transmitting function in the transceiver unit 1410 may be regarded as a transmitting unit, that is, the transceiver unit 1410 includes a receiving unit and a transmitting unit. The transceiver unit may also sometimes be referred to as a transceiver, a transceiver, or a transceiver circuit. The receiving unit may also sometimes be referred to as a receiver, receiver, or receiving circuit, or the like. The transmitting unit may also sometimes be referred to as a transmitter, a transmitter, or a transmitting circuit, or the like.

In a specific implementation manner, the transceiver unit 1410 is configured to perform the acquisition operation on the terminal device side in step 401 in FIG. 4 , and/or the transceiver unit 1410 is further configured to perform other transceiver steps on the terminal device side in this embodiment of the present application . The processing unit 1420 is configured to execute step 402 in FIG. 4 , and/or the processing unit 1420 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

In a specific implementation manner, the transceiver unit 1410 is configured to perform the acquisition operation on the terminal device side in step 501 in FIG. 5 , and/or the transceiver unit 1410 is further configured to perform other transceiver steps on the terminal device side in this embodiment of the present application . The processing unit 1420 is configured to execute step 502 in FIG. 5 , and/or the processing unit 1420 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

In a specific implementation manner, the transceiver unit 1410 is configured to perform the acquisition operation on the terminal device side in step 601 in FIG. 6 , and/or the transceiver unit 1410 is further configured to perform other transceiver steps on the terminal device side in this embodiment of the present application . The processing unit 1420 is configured to execute step 602, step 603 and step 604 in FIG. 6, and/or the processing unit 1420 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

In a specific implementation manner, the transceiver unit 1410 is configured to perform the acquisition operation on the terminal device side in step 901 in FIG. 9 , and/or the transceiver unit 1410 is further configured to perform other transceiver steps on the terminal device side in this embodiment of the present application . The processing unit 1420 is configured to execute step 902, step 903 and step 904 in FIG. 9, and/or the processing unit 1420 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

In a specific implementation manner, the transceiver unit 1410 is configured to perform the acquisition operation on the terminal device side in step 1001 in FIG. 10 , and/or the transceiver unit 1410 is further configured to perform other transceiver steps on the terminal device side in this embodiment of the present application . The processing unit 1420 is configured to execute step 1002, step 1003, step 1004 and step 1005 in FIG. 10, and/or the processing unit 1420 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

In a specific implementation manner, the transceiver unit 1410 is configured to perform the acquisition operation on the terminal device side in step 1101 in FIG. 11 , and/or the transceiver unit 1410 is further configured to perform other transceiver steps on the terminal device side in this embodiment of the present application . The processing unit 1420 is configured to execute step 1102 and step 1103 in FIG. 11 , and/or the processing unit 1420 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

In a specific implementation manner, the transceiving unit 1410 is configured to perform the acquisition operation on the terminal device side in step 1201 in FIG. 12 , and/or the transceiving unit 1410 is further configured to perform other transceiving steps on the terminal device side in this embodiment of the present application . The processing unit 1420 is configured to execute steps 1202 and 1203 in FIG. 12 , and/or the processing unit 1420 is further configured to execute other processing steps on the terminal device side in the embodiments of the present application.

Furthermore, the network device may be implemented by the communication device in FIG. 15 . FIG. 15 is a schematic diagram of a hardware structure of a communication device provided by an embodiment of the present application. It includes: a communication interface 1501 and a processor 1502, and may also include a memory 1503.

Communication interface 1501 may use any transceiver-like device for communicating with other devices or communication networks.

The processor 1502 includes, but is not limited to, a central processing unit (CPU), a network processor (NP), an application-specific integrated circuit (ASIC), or a programmable logic device (PLD). ) one or more of. The above-mentioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof. Processor 1502 is responsible for communication lines 1504 and general processing, and may also provide various functions, including timing, peripheral interface, voltage regulation, power management, and other control functions. Memory 1503 may be used to store data used by processor 1502 in performing operations.

Memory 1503 may be read-only memory (ROM) or other type of static storage device that can store static information and instructions, random access memory (RAM), or other type of static storage device that can store information and instructions The dynamic storage device can also be an electrically erasable programmable read-only memory (electrically programmable read-only memory, EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, Optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or capable of carrying or storing desired program code in the form of instructions or data structures and capable of Any other medium that can be accessed by a computer, but is not limited to this. The memory may exist independently and be connected to the processor 1502 through the communication line 1504 . The memory 1503 may also be integrated with the processor 1502. If the memory 1503 and the processor 1502 are separate devices, the memory 1503 and the processor 1502 are connected, for example, the memory 1503 and the processor 1502 can communicate through a communication line. The communication interface 1501 and the processor 1502 may communicate through a communication line, and the communication interface 1501 may also be directly connected to the processor 1502 .

Communication lines 1504 , which may include any number of interconnected buses and bridges, link together various circuits including one or more processors 1502 , represented by processor 1502 , and memory, represented by memory 1503 . Communication lines 1504 may also link together various other circuits, such as peripherals, voltage regulators, and power management circuits, which are well known in the art and, therefore, will not be described further herein.

In a specific embodiment, the network device may include: a memory for storing computer-readable instructions.

It also includes a communication interface coupled with the memory for sending a first message, where the first message carries first time information, an identifier of the first system frame and transmission delay reference information, and the first time information is the frame boundary of the first system The corresponding time, the first time information and the transmission delay reference information are used to indicate the second time, the second time is the time corresponding to the second system frame boundary of the terminal device, and the frame identifiers of the first system frame and the second system frame are the same. .

In a specific embodiment, the transmission delay reference information is location information of the network device, and the location information of the network device indicates the first transmission delay between the network device and the terminal device.

In a specific implementation manner, the transmission delay reference information is a second transmission delay between the network device and the first location, and the second transmission delay is used to indicate the second moment.

In a specific embodiment, the transmission delay reference information is the transmission power of the network device, the transmission indicates the path power loss, and the path power loss is related to the fourth transmission delay between the terminal device and the network device.

In a specific embodiment, the network device may include: a memory for storing computer-readable instructions. It also includes a communication interface coupled with the memory for sending a first message, where the first message carries the first time information and the identifier of the first system frame.

The communication interface is also used to send the timing advance amount TA, the first time information and TA are used by the terminal device to determine the second time, the second time is the time corresponding to the second system frame boundary of the terminal device, the first system frame and the second time. The frame ID of the system frame is the same.

In a specific embodiment, it also includes: a processor coupled with the communication interface for executing computer-readable instructions in the memory to perform the following operations: configuring the first timer of the terminal device to have a duration of T, and the first timer The timer does not time out for the terminal device to determine that the TA is valid.

In the embodiments of the present application, the communication interface may be regarded as a transceiver unit of the network device, the processor with processing function may be regarded as the processing unit of the network device, and the memory may be regarded as the storage unit of the network device. As shown in FIG. 16 , the network device may include a transceiver unit 1610 and a processing unit 1620 . The transceiving unit may also be referred to as a transceiver, a transceiver, a transceiving device, or the like. The processing unit may also be referred to as a processor, a processing single board, a processing module, a processing device, and the like. Optionally, the device for implementing the receiving function in the transceiver unit 1610 may be regarded as a receiving unit, and the device for implementing the transmitting function in the transceiver unit 1610 may be regarded as a transmitting unit, that is, the transceiver unit 1610 includes a receiving unit and a transmitting unit. The transceiver unit may also sometimes be referred to as a transceiver, a transceiver, or a transceiver circuit. The receiving unit may also sometimes be referred to as a receiver, receiver, or receiving circuit, or the like. The transmitting unit may also sometimes be referred to as a transmitter, a transmitter, or a transmitting circuit, or the like.

In a specific implementation manner, the transceiving unit 1610 is configured to perform the transceiving operation on the network device side in step 401 in FIG. 4 , and/or the transceiving unit 1610 is further configured to perform other transceiving steps on the network device side in this embodiment of the present application .

In a specific implementation manner, the transceiving unit 1610 is configured to perform the transceiving operation on the network device side in step 501 in FIG. 5 , and/or the transceiving unit 1610 is further configured to perform other transceiving steps on the network device side in this embodiment of the present application .

In a specific implementation manner, the transceiving unit 1610 is configured to perform the transceiving operation on the network device side in step 601 in FIG. 6 , and/or the transceiving unit 1610 is further configured to perform other transceiving steps on the network device side in this embodiment of the present application .

In a specific implementation manner, the transceiving unit 1610 is configured to perform the transceiving operation on the network device side in step 901 in FIG. 9 , and/or the transceiving unit 1610 is further configured to perform other transceiving steps on the network device side in this embodiment of the present application .

In a specific implementation manner, the transceiving unit 1610 is configured to perform the transceiving operation on the network device side in step 1001 in FIG. 10 , and/or the transceiving unit 1610 is further configured to perform other transceiving steps on the network device side in this embodiment of the present application .

In a specific implementation manner, the transceiving unit 1610 is configured to perform the transceiving operation on the network device side in step 1101 in FIG. 11 , and/or the transceiving unit 1610 is further configured to perform other transceiving steps on the network device side in this embodiment of the present application . The processing unit 1620 is configured to execute step 1103 in FIG. 11 , and/or the processing unit 1620 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

In a specific implementation manner, the transceiving unit 1610 is configured to perform the transceiving operation on the network device side in step 1201 in FIG. 12 , and/or the transceiving unit 1610 is further configured to perform other transceiving steps on the network device side in this embodiment of the present application . The processing unit 1620 is configured to execute step 1203 in FIG. 12 , and/or the processing unit 1620 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in software, it can be implemented in whole or in part 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 described in the embodiments of the present application are generated. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server, or data center Transmission to another website site, computer, server, or data center is by wire (eg, coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg, infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be stored by a computer, or a data storage device such as a server, data center, etc., which includes one or more available media integrated. The usable media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, DVD), or semiconductor media (eg, Solid State Disk (SSD)), among others.

Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage medium can include: ROM, RAM, magnetic disk or optical disk, etc.

The communication method, terminal device, network device, and storage medium provided by the embodiments of the present application have been described in detail above, and the principles and implementations of the present application are described with specific examples. The descriptions in the above embodiments are only used for Help to understand the method of the present application and its core idea; meanwhile, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation and application scope. In summary, the content of this specification It should not be construed as a limitation of this application.

Claims (33)

1. A method of communication, comprising:

a terminal device acquires a first message, wherein the first message carries first time information, an identifier of a first system frame and transmission delay reference information, and the first time information is a moment corresponding to a first system frame boundary;

And the terminal equipment determines a second moment according to the first time information and the transmission delay reference information, wherein the second moment is a moment corresponding to a second system frame boundary of the terminal equipment, and the frame identifications of the first system frame and the second system frame are the same.

2. The method of claim 1, wherein the transmission delay reference information is location information of a network device;

the determining, by the terminal device, a second time according to the first time information and the transmission delay reference information includes:

the terminal equipment determines the second moment according to the first time information and the first transmission delay;

wherein the first transmission delay is determined according to the location information of the network device and the location information of the terminal device.

3. The method of claim 1, wherein the transmission delay reference information is a second transmission delay between the network device and a first location, and the first location is a predetermined or defined location or a reference location;

the determining, by the terminal device, a second time according to the first time information and the transmission delay reference information includes:

The terminal equipment determines the second moment according to the first time information, the second transmission delay and a third transmission delay;

wherein the third transmission delay is determined according to the terminal device and the first position.

4. The method of claim 1, wherein the transmission delay reference information is a transmission power of the network device;

the determining, by the terminal device, a second time according to the first time information and the transmission delay reference information includes:

the terminal equipment determines the second moment according to the first time information and a fourth transmission delay;

wherein the fourth transmission delay is a transmission delay from the network device to the terminal device determined according to a path power loss, and the path power loss is determined according to a transmission power of the network device.

5. The method of claim 4, wherein:

the fourth transmission delay is determined according to one or more of the path power loss, the information transmission frequency and the information transmission speed, and the path power loss is determined according to the transmission power of the network device and the reception power of the terminal device.

6. A method of communication, comprising:

a terminal device acquires a first message, wherein the first message carries first time information and an identifier of a first system frame, and the first time information is a moment corresponding to a first system frame boundary;

and the terminal equipment determines a second time according to the first time information and a Timing Advance (TA), wherein the second time is a time corresponding to a second system frame boundary of the terminal equipment, and the frame identifications of the first system frame and the second system frame are the same.

7. The method of claim 6, wherein:

the TA corresponds to a first timer, and the duration of the first timer is T;

before the terminal device determines a second time according to the first time information and the TA, the method further includes:

and the terminal equipment determines that the first timer is not overtime.

8. The method of claim 7, wherein:

the duration T is configured by the network device; or

The duration T is determined by the terminal equipment according to the moving state; or

The duration T is determined by the terminal device according to the mobility state and the configuration of the network device.

9. A method of communication, comprising:

the method comprises the steps that a network device sends a first message, wherein the first message carries first time information, an identifier of a first system frame and transmission delay reference information, the first time information is a moment corresponding to a first system frame boundary, the first time information and the transmission delay reference information are used for indicating a second moment, the second moment is a moment corresponding to a second system frame boundary of a terminal device, and frame identifiers of the first system frame and the second system frame are the same.

10. The method of claim 9, wherein the transmission delay reference information is location information of the network device, and the location information of the network device indicates a first transmission delay between the network device and the terminal device.

11. The method of claim 9, wherein the transmission delay reference information is a second transmission delay between the network device and a first location, and wherein the second transmission delay indicates the second time.

12. The method of claim 9, wherein the transmission delay reference information is a transmit power of the network device, wherein the transmit power indicates a path power loss, and wherein the path power loss is related to a fourth transmission delay between the terminal device and the network device.

13. A method of communication, comprising:

the method comprises the steps that network equipment sends a first message, wherein the first message carries first time information and an identifier of a first system frame;

the network device sends a Timing Advance (TA), the first time information and the TA are used for indicating a second time, the second time is a time corresponding to a second system frame boundary, and the frame identifications of the first system frame and the second system frame are the same.

14. The method of claim 13, further comprising:

the network equipment configures a first timer, the duration of the first timer is T, and the first timer is used for indicating whether the TA is valid.

15. An apparatus, comprising:

a memory for storing computer readable instructions;

the communication interface is coupled with the memory and is used for acquiring a first message, wherein the first message carries first time information, an identifier of a first system frame and transmission delay reference information, and the first time information is a moment corresponding to a boundary of the first system frame;

further comprising: a processor coupled with the communication interface to execute the computer readable instructions in the memory to perform the following:

And determining a second moment according to the first time information and the transmission delay reference information, wherein the second moment is a moment corresponding to a second system frame boundary of the terminal equipment, and the frame identifications of the first system frame and the second system frame are the same.

16. The apparatus of claim 15, wherein the transmission delay reference information is location information of a network device;

the processor is specifically configured to determine the second time according to the first time information and a first transmission delay, where the first transmission delay is determined according to the location information of the network device and the location information of the terminal device.

17. The apparatus of claim 15, wherein the transmission delay reference information is a second transmission delay between the network device and a first location, and the first location is a predetermined or defined location or a reference location;

the processor is specifically configured to determine a second time according to the first time information, the second transmission delay, and the third transmission delay, where the third transmission delay is determined according to the terminal device and the first location.

18. The apparatus of claim 15, wherein the transmission delay reference information is a transmission power of the network device;

the processor is specifically configured to determine the second time according to the first time information and a fourth transmission delay, where the fourth transmission delay is a transmission delay from the network device to the terminal device that is determined according to a path power loss, and the path power loss is determined according to a transmission power of the network device.

19. The apparatus of claim 18,

the fourth transmission delay is determined according to one or more of the path power loss, the information transmission frequency and the information transmission speed, and the path power loss is determined according to the transmission power of the network device and the reception power of the terminal device.

20. An apparatus, comprising:

a memory for storing computer readable instructions;

the communication interface is coupled with the memory and is used for acquiring a first message, wherein the first message carries first time information and an identifier of a first system frame, and the first time information is a moment corresponding to a boundary of the first system frame;

Further comprising: a processor coupled with the communication interface to execute the computer readable instructions in the memory to perform the following:

and determining a second time according to the first time information and a Timing Advance (TA), wherein the second time is a time corresponding to a second system frame boundary of the terminal equipment, and the frame identifications of the first system frame and the second system frame are the same.

21. The apparatus of claim 20, wherein:

the TA corresponds to a first timer, and the duration of the first timer is T;

the processor is further configured to determine that the first timer has not timed out.

22. The apparatus of claim 21, wherein:

the duration T is configured by the network device; or

The duration T is determined by the terminal equipment according to the moving state; or

The duration T is determined by the terminal device according to the mobility state and the configuration of the network device.

23. An apparatus, comprising:

a memory for storing computer readable instructions;

the communication interface is coupled to the memory and configured to send a first message, where the first message carries first time information, an identifier of a first system frame, and transmission delay reference information, the first time information is a time corresponding to a boundary of the first system frame, the first time information and the transmission delay reference information are used to indicate a second time, the second time is a time corresponding to a boundary of a second system frame of the terminal device, and frame identifiers of the first system frame and the second system frame are the same.

24. The apparatus of claim 23, wherein the transmission delay reference information is location information of a network device, and wherein the location information of the network device indicates a first transmission delay between the network device and the terminal device.

25. The apparatus of claim 23, wherein the transmission delay reference information is a second transmission delay between the network device and a first location, and wherein the second transmission delay indicates the second time, and wherein the first location is a predetermined or defined location or the first location is a reference location.

26. The apparatus of claim 23, wherein the transmission delay reference information is a transmit power of the network device, wherein the transmit power indicates a path power loss, and wherein the path power loss is related to a fourth transmission delay between the terminal device and the network device.

27. An apparatus, comprising:

a memory for storing computer readable instructions;

the communication interface is coupled with the memory and used for sending a first message, wherein the first message carries first time information and an identifier of a first system frame;

The communication interface is further configured to send a timing advance TA, where the first time information and the TA are used by the terminal device to determine a second time, the second time is a time corresponding to a second system frame boundary of the terminal device, and frame identifiers of the first system frame and the second system frame are the same.

28. The apparatus of claim 27, further comprising: a processor coupled with the communication interface to execute the computer readable instructions in the memory to perform the following:

and configuring the duration of a first timer of the terminal equipment as T, wherein the first timer is not overtime and is used for the terminal equipment to determine that the TA is effective.

29. A communication system, characterized in that the communication system comprises a terminal device and a network device, wherein,

the terminal device is the terminal device of any one of claims 1 to 8;

the network device of any one of claims 9 to 14.

30. A computer-readable storage medium, which when executed on a computer device, causes the computer device to perform the method of any one of claims 1 to 8.

31. A computer-readable storage medium, which when executed on a computer device, causes the computer device to perform the method of any one of claims 9 to 14.

32. A computer program product enabling a computer to carry out the method of any one of claims 1 to 8 when run on the computer.

33. A computer program product enabling a computer to carry out the method of any one of claims 9 to 14 when run on the computer.

Images