Enhanced pulse assisted time synchronization protocol

A method comprising:

• receiving, with a time client device, a synchronization start message from a time server, wherein the synchronization start message includes a local time of the time server indicating when the synchronization start message was sent by the time server;
• setting, with the time client device, a current time of day of the time client device based on the local time of the time server as included within the synchronization start message, wherein setting the current time of day comprises:
• (i) when a fractional portion of a unit seconds portion of a local client time when the time client device received the synchronization start message is greater than a fractional portion of a unit seconds portion of the local time of the time server as included within the synchronization start message, setting the current time of day of the time client device using a same value of the unit seconds portion of the local time of the time server as included within the synchronization start message, and
• (ii) when the fractional portion of the unit seconds portion of the local client time when the time client device received the synchronization start message is less than the fractional portion of the unit seconds portion of the local time of the time server as included within the synchronization start message, setting the current time of day of the time client device by adding one second to the value of the unit seconds portion of the local time of the time server as included within the synchronization start message;
• after setting the current time of day of the time client device, sending, with the time client device, a synchronization response message to the time server to indicate that the current time of day of the time client device was set based on the local time of the time server as included within the synchronization start message, wherein the synchronization response message includes a local time of the time client device indicating when the time client device sent the synchronization response message;
• and
• receiving, with the time client device, a synchronization success message from the time server when the time server determines that the difference between the local time of the time client device as included in the synchronization response message and a local time of the time server indicating when the time server received the synchronization response message is less than one second, wherein the synchronization success message indicates that the time client device has correctly set its current time of day.

A network device comprising:

• a timing module that determines a local time of the network device indicating when the network device sends a synchronization start message;
• at least one interface that sends the synchronization start message to a time client device to set a current time of day on the time client device, receives a synchronization response message from the time client device indicating that the client device received the synchronization start message and performed an operation of setting the current time of day of the time client device based on the local time of the network device as included within the synchronization start message indicating when the network device sent the synchronization start message, and sends a synchronization success message to the time client device indicating that the time client device has correctly set its current time of day,
• wherein the synchronization response message includes a local time of the time client device indicating when the synchronization response message was sent by the time client device,
• wherein the at least one interface receives a primary reference time, and wherein the timing module determines the local time of the network device indicating when the network device sent the synchronization start message and a local time of the network device indicating when the network device received the synchronization response message based on the primary reference time;
• and
• a clock generator that delivers a clock signal, wherein the clock generator phase shifts at least one of a rising or falling edge of the clock signal such that the at least one of the rising or falling edge occurs at a time subsequent to the primary reference time,
• wherein the timing module determines a time difference between the local time of the network device indicating when the network device received the synchronization response message and the local time of the time client device as set based on the local time of the time server as included in the synchronization response message indicating when the synchronization response message was sent by the time client device, and wherein the interface sends the synchronization success message when the timing module determines that the time difference is less than a threshold time value.

A network device comprising:

• at least one interface that receives a synchronization start message from a time server, wherein the synchronization start message includes a local time of the time server indicating when the synchronization start message was sent by the time server;
• and
• a timing module that sets a current time of day of the network device based on the local time of the time server as included within the synchronization start message, and determines a local time of the network device indicating when the network device sends a synchronization response message, wherein the timing module sets the current time of day by:
• (i) when a fractional portion of a unit seconds portion of a local client time when the time client device received the synchronization start message is greater than a fractional portion of a unit seconds portion of the local time of the time server as included within the synchronization start message, setting the current time of day of the time client device using a same value of the unit seconds portion of the local time of the time server as included within the synchronization start message, and
• (ii) when the fractional portion of the unit seconds portion of the local client time when the time client device received the synchronization start message is less than the fractional portion of the unit seconds portion of the local time of the time server as included within the synchronization start message, setting the current time of day of the time client device by adding one second to the value of the unit seconds portion of the local time of the time server as included within the synchronization start message,
• wherein after setting the current time of day of the time client device, the at least one interface sends the synchronization response message to the time server to indicate that the current time of day of the network device was set based on the local time of the time server as included within the synchronization start message, and wherein the synchronization response message includes the local time of the network device indicating when the network device sends the synchronization response message, and
• wherein the at least one interface receives a synchronization success message from the time server when the time server determines that the difference between the local time of the network device as included in the synchronization response message and a local time of the time server indicating when the time server received the synchronization response message is less than one second, wherein the synchronization success message indicates that the network device has correctly set its current time of day.