Method and system for accurate clock synchronization for communication networks

A communication system comprising:

• a sender and a receiver, configured for communicating over a communication link;
• the receiver comprising a synchronization manager configured for:
• determining (a)the retrieved sender local time phyTxTime for transmission of a first synchronization packet, and (b) the receiver local time phyRxTimePrevious for receipt of a first synchronization packet at the receiver, for determining a time difference D1 between:
• (a) the 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, and for sending a second and third synchronization packet from the sender to the receiver, wherein the third synchronization packet is timestamped with the value recorded in phyTxTime indicating said sender local time when the second synchronization packet was placed on the link, and to update the receiver local time based on said time difference D1 to time synchronize the receiver with the sender.

A transmission sender configured for communicating over a communication link, the sender comprising:

• a sender communication module configured for sending a first synchronization signal to a receiver;
• and
• a sender synchronization manager configured for determining the sender local time when the first synchronization signal was placed on the link for transmission, wherein the sender synchronization manager is further configured for:
• sending a second synchronization packet from the sender to the receiver, wherein the second synchronization packet is timestamped with said recorded sender local time when the first synchronization packet was placed on the link;
• and
• sending a third synchronization packet from the sender to the receiver,
• wherein the receiver retrieves the second packet timestamp to determine a time difference D1 between the retrieved sender local time when the first synchronization packet was placed on the link for transmission and said recorded receiver local time when the first synchronization packet was received from the link, and further update the receiver local time based on said time difference D1 to time synchronize the receiver with the sender;

A transmission receiver configured for communicating over a communication link, the receiver comprising:

• a receiver communication module that is configured for receiving a synchronization signal including a packet over a communication link from a sender;
• and
• a receiver synchronization manager configured for determining a time difference D1 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 D1 further includes determining a time difference between (a) the retrieved sender local time phyTxTime for transmission of the first synchronization packet, and (b) the receiver local time phyRxTimePrevious for receipt of the first synchronization packet at the receiver.

A sender configured for communicating over a communication link, the sender comprising:

• a sender communication module configured for transmitting a first synchronization signal;
• and
• a sender synchronization manager configured for:
• determining the sender local time when the first synchronization signal was placed on the link for transmission;
• recording the sender local time when the first synchronization packet is placed on the link for transmission;
• transmitting a second synchronization packet, wherein the second synchronization packet is timestamped with said recorded sender local time when the first synchronization packet was placed on the link;
• and
• transmitting a third synchronization packet,
• wherein the second packet timestamp is used to determine a time difference D1 between a retrieved sender local time when the first synchronization packet was placed on the link for transmission and said recorded local time when the first synchronization packet was received from the link, and further update the local time based on said time difference D1 for time synchronization.

A method for communicating using a sender configured for communicating over a communication link, the method comprising:

• transmitting a first synchronization signal from a sender communication module;
• using the sender synchronization manager for:
• determining the sender local time when the first synchronization signal was placed on the link for transmission
• recording the sender local time when the first synchronization packet is placed on the link for transmission;
• transmitting a second synchronization packet, wherein the second synchronization packet is timestamped with said recorded sender local time when the first synchronization packet was placed on the link,
• wherein the second packet timestamp is used to determine a time difference D1 between a retrieved sender local time when the first synchronization packet was placed on the link for transmission and said recorded local time when the first synchronization packet was received from the link, and further update the local time based on said time difference D1 for time synchronization;
• and

A receiver configured for communicating over a communication link, the receiver comprising:

• a communication module configured for receiving a first synchronization signal;
• and
• a synchronization manager configured for:
• determining local time when the first synchronization signal was placed on the link for transmission;
• recording the local time when the first synchronization packet is placed on the link for transmission to the receiver;
• receiving a second synchronization packet, wherein the second synchronization packet is timestamped with said recorded local time when the first synchronization packet was placed on the link,
• wherein the receiver retrieves the second packet timestamp to determine a time difference D1 between the retrieved local time when the first synchronization packet was placed on the link for transmission and said recorded receiver local time when the first synchronization packet was received from the link, and further update the receiver local time based on said time difference D1 for time synchronization.

A method to communicate using a receiver over a communication link, the method comprising:

• receiving a first synchronization signal using a communication module;
• using a synchronization manager for:
• determining local time when the first synchronization signal was placed on the link for transmission;
• recording the local time when the first synchronization packet is placed on the link for transmission to the receiver;
• and
• receiving a second synchronization packet, wherein the second synchronization packet is timestamped with said recorded local time when the first synchronization packet was placed on the link;
• and
• retrieving the second packet timestamp by the receiver for determining a time difference D1 between the retrieved local time when the first synchronization packet was placed on the link for transmission and said recorded receiver local time when the first synchronization packet was received from the link, and further updating the receiver local time based on said time difference D1 for time synchronization.