Accurate synchronization as a service

Patent metadata

Field	Value
Publication number	US-10476618-B2
Application number	US-201916397829-A
Country	US
Kind code	B2
Filing date	Apr 29, 2019
Priority date	Apr 19, 2016
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

Novel tools and techniques are provided for implementing network timing functionality. In some embodiments, a grand master clock(s) might receive a first timing signal from a global positioning system (“GPS”) source via a GPS antenna(s), and might send a second timing signal (which might be based at least in part on the first timing signal) to a slave clock(s), in some cases, via one or more network elements or the like. A computing system might calculate various transmission times for the second timing signal to be transmitted between the grand master clock(s) and the slave clock(s), and might calculate any time delay differences in the transmission times, might generate a third timing signal based at least in part on the calculated time delay differences (if any), and might send the third timing signal to one or more network elements, thereby providing Accurate Synchronization as a Service (“ASaaS”) functionality.

First claim

What is claimed is:

1. A method for implementing accurate synchronization as a service (“ASaaS”) functionality, comprising:
receiving, with a first grand master clock, a first timing signal from a first global positioning system (“GPS”) source;
sending, with the first grand master clock, a second timing signal to a first slave clock via a first network path in a first network, the second timing signal being based at least in part on the first timing signal;
sending, with the first grand master clock, the second timing signal to the first slave clock via a second network path in the first network, the second network path being different from the first network path;
calculating, with a computing system, a first transmission time for the second timing signal to be transmitted between the first grand master clock and the first slave clock via the first network path;
calculating, with the computing system, a second transmission time for the second timing signal to be transmitted between the first grand master clock and the first slave clock via the second network path;
based on a determination that the first transmission time and the second transmission time are different, calculating, with the computing system, a time delay difference between the first network path and the second network path in terms of sending the second timing signal to the first slave clock;
generating, with the computing system, a third timing signal, based at least in part on the second timing signal and the calculated time delay difference between the first network path and the second network path; and
sending, with the computing system, the generated third timing signal to a network node disposed within a second network.

2. The method of claim 1 , wherein the third timing signal comprises a precision time protocol (“PTP”) timing signal, the PTP timing signal comprising frequency information, phase information, and time of day information.

3. The method of claim 2 , wherein the second network is a wireless carrier network associated with a wireless carrier, wherein the network node comprises at least one base band unit (“BBU”), wherein the first slave clock and the at least one BBU are disposed within at least one of a central office or a BBU hotel associated with the wireless carrier, and wherein the PTP timing signal is used to provide timing and synchronization between backhaul and fronthaul networks associated with the wireless carrier.

4. The method of claim 3 , wherein the first network and the second network are the same network, wherein the first grand master clock is disposed within the at least one of the central office or the BBU hotel associated with the wireless carrier, and wherein the at least one of the central office or the BBU hotel comprises at least one rooftop cable penetration through which a cable provides the first timing signal to the first grand master clock, via an optical converter, from at least one GPS antenna that communicatively couples to the first GPS source.

5. The method of claim 3 , wherein the PTP timing signal is a virtual PTP timing signal, wherein the at least one BBU comprises at least one virtual BBU (“vBBU”), wherein the first slave clock comprises a timing virtual machine (“VM”) that is created in each of at least one pod, wherein the first grand master clock and the at least one pod are disposed within the at least one of the central office or the BBU hotel associated with the wireless carrier, wherein the first grand master clock communicatively couples with the at least one pod via optical fiber communication, wherein the at least one of the central office or the BBU hotel comprises at least one rooftop cable penetration through which a cable provides the first timing signal to the first grand master clock from at least one GPS antenna that communicatively couples to the first GPS source, and wherein the at least one vBBU receives time information and time synchronization, via the virtual PTP timing signal, directly from the at least one pod.

6. The method of claim 1 , further comprising:
receiving, with a second grand master clock, a fourth timing signal from at least one of the first GPS source or a second GPS source;
sending, with the second grand master clock, a fifth timing signal to a second slave clock via a third network path in the first network, the fifth timing signal being based at least in part on the fourth timing signal, the third network path being different from any of the first network path or the second network path;
sending, with the second grand master clock, the fifth timing signal to the second slave clock via a fourth network path in the first network, the fourth network path being different from any of the first network path, the second network path, or the third network path;
calculating, with the computing system, a third transmission time for the fifth timing signal to be transmitted between the second grand master clock and the second slave clock via the third network path;
calculating, with the computing system, a fourth transmission time for the fifth timing signal to be transmitted between the second grand master clock and the second slave clock via the fourth network path;
based on a determination that the third transmission time and the fourth transmission time are different, calculating, with the computing system, a time delay difference between the third network path and the fourth network path in terms of sending the fifth timing signal to the second slave clock;
generating, with the computing system, a sixth timing signal, based at least in part on the fifth timing signal and the calculated time delay difference between the third network path and the fourth network path and based at least in part on the second timing signal and the calculated time delay difference between the first network path and the second network path; and
sending, with the computing system, the generated sixth timing signal to the network node disposed within the second network.

7. The method of claim 6 , wherein the first network path comprises a first sequence of a first plurality of network elements through which the second timing signal is sent, the second network path comprises a second sequence of the same first plurality of network elements through which the second timing signal is sent, and the second sequence is the opposite of the first sequence; and wherein the third network path comprises a third sequence of a second plurality of network elements through which the fifth timing signal is sent, the fourth network path comprises a fourth sequence of the same second plurality of network elements through which the fifth timing signal is sent, and the fourth sequence is the opposite of the third sequence.

8. The method of claim 1 , wherein the first network path and the second network path each comprises at least one of open systems interconnection (“OSI”) model layer 3 network devices, routers, and switches or OSI model layer 2 network devices and switches, wherein the first grand master clock is disposed within a service provider central office in the first network.

9. The method of claim 1 , wherein the first network path and the second network path each comprises OSI model 1 network devices, wherein the first grand master clock is communicatively coupled with a reconfigurable optical add-drop multiplexer (“ROADM”).

10. The method of claim 1 , wherein sending the generated third timing signal to the network node comprises sending, with the computing system, the generated third timing signal to the network node disposed within the second network via optical fiber communication between the computing system and the network node.

11. The method of claim 1 , wherein

Assignees

• Centurylink Ip Llc

Inventors

• Farra Jeff
• Johnson Paul
• Schwengler Thomas

Classifications

• H04J3/0667

  Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays (arrangements for monitoring round trip delays in packet switching networks H04L43/0864) · CPC title

• H04W56/0045

  compensating for timing error by altering transmission time · CPC title

• H04J3/0682

  by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging · CPC title

• H04J3/0644

  External master-clock · CPC title

• H04J3/0673 Primary

  using intermediate nodes, e.g. modification of a received timestamp before further transmission to the next packet node, e.g. including internal delay time or residence time into the packet · CPC title