METHOD, APPARATUS, AND SYSTEM FOR TIME SYNCHRONIZATION OF XDSL

摘要

An x digital subscriber line (xDSL) time synchronization method, apparatus and system are provided in present invention. The method includes that a customer premises equipment sends a first symbol to a central office, and obtains a time Ts2 of sending the first symbol; the customer premises equipment receives a second symbol sent by the central office, and obtains a time Ts1 of receiving the second symbol; the customer premises equipment obtains a time Tm2 of receiving the first symbol by the central office, and a time Tm1 of sending the second symbol by the central office; the customer premises equipment calculates the offset between the clock of the customer premises equipment and the clock of the central office based on the Ts1, Ts2, Tm1, Tm2 and the delay of the customer premises equipment; the customer premises equipment adjusts the clock of the customer premises equipment based on the offset to realize synchronization. By adjusting the read clock time of the customer premises equipment and the read clock time of the central office in present invention, the offset between the clock of the customer premises equipment and the clock of the central office can be obtained correctly, and the time synchronization between the customer premises equipment and the central office can be realized effectively.