Time synchronization method, apparatus, and system

A time synchronization method, comprising:

• sending, by a master node, a first signal to a slave node, wherein the first signal comprises a first synchronization sequence, and the first synchronization sequence is inserted at a channel layer of the master node;
• sending, by the master node, first information to the slave node, wherein the first information indicates a moment T1 at which the master node sends the first synchronization sequence;
• receiving, by the master node, a second signal from the slave node, wherein the second signal comprises a second synchronization sequence;
• detecting, by the master node, the second synchronization sequence from the second signal, wherein a moment of detecting the second synchronization sequence is T4;
• and
• sending, by the master node, second information to the slave node, wherein the second information indicates T4, and T1 and T4 are used for time synchronization between the master node and the slave node.

A node, comprising:

• a memory configured to store a computer program instruction;
• and
• a processor coupled to the memory, wherein the computer program instruction causes the node to be configured to:
• receive a first signal from a master node, wherein the first signal comprises a first synchronization sequence;
• detect the first synchronization sequence from the first signal, wherein a moment of detecting the first synchronization sequence is T2;
• receive first information from the master node, wherein the first information indicates a moment T1 at which the master node sends the first synchronization sequence;
• send a second synchronization sequence to the master node, wherein a moment of sending the second synchronization sequence is T3, and the second synchronization sequence is inserted at the channel layer of the slave node;
• and
• receive second information from the master node, wherein the second information is used to indicate a moment T4 at which the master node detects a quantized form of the second synchronization sequence;
• and
• perform time synchronization between the slave node and the master node based on T1, T2, T3, and T4.

A node, comprising:

• a memory configured to store a computer program instruction;
• and
• a processor coupled to the memory, wherein the computer program instruction causes the node to be configured to:
• send a first signal to a slave node, wherein the first signal comprises a first synchronization sequence, and the first synchronization sequence is inserted at a channel layer of the master node;
• send first information to the slave node, wherein the first information indicates a moment T1 at which the master node sends the first synchronization sequence;
• receive a second signal from the slave node, wherein the second signal comprises a second synchronization sequence;
• detect the second synchronization sequence from the second signal, wherein a moment of detecting the second synchronization sequence is T4;
• and
• send second information to the slave node, wherein the second information indicates T4, and T1 and T4 are used for time synchronization between the master node and the slave node.