METHOD AND APPARATUS FOR DETERMINING PROPAGATION DELAY IN A COMMUNICATIONS NETWORK

摘要

A method and apparatus for determining propagation delay of a first path and or of a second path which connect a first transceiver unit associated with a first clock to a second transceiver unit associated with a second clock in a communications network. The apparatus comprises a control unit configured to cause the first transceiver unit to transmit a first signal to the second transceiver unit over the first path and to receive a reply to the first signal from the second transceiver unit over the second path, and to transmit a second signal to the second transceiver unit over the second path and to receive a reply to the second signal from the second transceiver unit over the first path. The apparatus further comprises a receiving unit configured to receive a first time reference representing the time of transmission of the first signal from the first transceiver unit, a second time reference representing the time of receipt of the first signal at the second transceiver unit, a third time reference representing the time of transmission of the reply to the second signal from the second transceiver unit and a fourth time reference representing the time of receipt of the reply to the second signal at the first transceiver unit. The apparatus further comprises a determining unit configured to determine a propagation delay of the first path and or of the second path using the first time reference, the second time reference, the third time reference and the fourth time reference.