Patent ID: 8023976

Claim:
A method of time synchronization between a sender and a receiver connected via a communication link, comprising: sending a first synchronization signal from the sender to the receiver, and determining the sender local time when the first synchronization signal was placed on the link for transmission, wherein sending the first synchronization signal includes: creating a first synchronization packet in a Media Access Control (MAC) layer of the sender, providing the first synchronization packet from the MAC layer to a physical (PHY) layer of the sender, and the PHY layer transmitting the synchronization packet on the link; and determining said sender local time includes: the sender PHY layer determining the sender local time when the first synchronization packet is placed on the link by the sender PHY layer for transmission to the receiver; receiving the first synchronization signal at the receiver, and determining the receiver local time when the first synchronization signal was received from the link; determining a time difference D 1 between: (a) a retrieved sender local time when the first synchronization packet was placed on the link for transmission, and (b) said recorded receiver local time when the first synchronization packet was received from the link, wherein determining the time difference D 1 further includes: determining a difference between (a) the retrieved sender local time phyTxTime for transmission of the first synchronization packet, and (b) a retrieved receiver local time phyPxTimePrevious for receipt of the first synchronization packet at the receiver; updating the receiver local time based on said time difference D 1 to time synchronize the receiver with the sender; maintaining a phyRxTimePrevious in a MAC Management Information Base (MIB); and upon receiving a synchronization packet at the receiver MAC layer from the receiver PHY layer, copying the value in phyRxTime to phyRxTimePrevious.