US-12627391-B2 - Integrating terrestrial time feed with data center distribution networks for clock synchronization

US12627391B2US 12627391 B2US12627391 B2US 12627391B2US-12627391-B2

Abstract

In general, the disclosure describes techniques and devices for integrating a terrestrial time feed with one or more computer networks also having a global positioning source (GPS)-based reference time feed to provide improved computing device clock synchronization.

Inventors

Denis Phillip Reilly
Vadim Shmatko
Ankur Sharma
Venkatesan Ramakrishnan

Assignees

EQUINIX, INC.

Dates

Publication Date: 20260512
Application Date: 20231222

Claims (20)

1 . A method comprising: receiving, by a computing system and via a terrestrial system, a first time signal originating from a first time source of a terrestrial time provider site, wherein the first time source is geographically distant from the computing system, and wherein the terrestrial system comprises a physical fiber that transmits the first time signal as an optical signal directly between a first patch panel local to the first time source and a second patch panel of a data center site hosting the computing system; receiving, by the computing system and via a Global Positioning System (GPS) and a GPS receiver of the data center site, a second time signal originating from the first time source; comparing, by the computing system, a time obtained from the first time signal to a time obtained from the second time signal over a time period; performing, by the computing system and based on the comparison, an action related to one or more of the first time signal or the second time signal; and providing, by the computing system and via a software-defined interconnection configured in a cloud fabric of the data center site, a timing service to one or more client devices based on the action and one or more of the first time signal or the second time signal.
2 . The method of claim 1 , wherein the physical fiber comprises a wave circuit, the wave circuit comprising a wavelength-division multiplexing (WDM), dense wavelength-division multiplexing (DWDM), or coarse wavelength-divisional multiplexing (CWDM) based wave circuit that transmits the first time signal as the optical signal.
3 . The method of claim 1 , wherein the physical fiber comprises an Optical Transport Network (OTN) circuit.
4 . The method of claim 1 , wherein performing an action based on the comparison comprises: when the timing service uses the first time signal as a primary time source, switching, by the computing system, to use the second time signal as the primary time source based on determining the first time signal is unreliable.
5 . The method of claim 1 , wherein performing an action based on the comparison comprises: when the timing service uses the second time signal as a primary time source, switching, by the computing system, to use the first time signal as the primary time source based on determining the second time signal is unreliable.
6 . The method of claim 1 , wherein performing an action based on the comparison comprises: when the timing service uses the first time signal as a primary time source, outputting, by the computing system for display, an indication of a quality of the first time signal based on the comparison.
7 . The method of claim 1 , wherein performing an action based on the comparison comprises: when the timing service uses the second time signal as a primary time source, outputting, for display, an indication of a quality of the second time signal based on the comparison.
8 . The method of claim 1 , wherein performing an action based on the comparison comprises outputting an alert notification indicating a difference between the first time signal and the second time signal has crossed a predefined threshold.
9 . The method of claim 1 , wherein the physical fiber comprises a first physical fiber, wherein the GPS system comprises a first GPS system, wherein the GPS receiver comprises a first GPS receiver, and wherein the comparison comprises a first comparison, the method further comprising: receiving, by the computing system and via the terrestrial system, a third time signal originating from a second time source, wherein the second time source is geographically distant from the computing system, and wherein the terrestrial system comprises a second physical fiber that transmits the third time signal as an optical signal directly between a third patch panel local to the second time source and a fourth patch panel local to the computing system; receiving, by the computing system and via a second GPS system and a second GPS receiver, a fourth time signal originating from the second time source; and comparing, by the computing system, a time obtained from the third time signal to a time obtained from the fourth time signal over a time period as a second comparison, wherein performing an action comprises performing, based on the first comparison and the second comparison, the action.
10 . The method of claim 9 , wherein comparing the first time signal to the second time signal yields first difference information, and wherein comparing the third time signal to the fourth time signal yields second difference information, the method further comprising: comparing the first difference information to the second difference information to obtain a delta, and wherein performing the action comprises performing the action based at least in part on the delta.
11 . A time synchronization system comprising: a first time source of a terrestrial time provider site; a Global Positioning System (GPS); a computing system hosted by a data center site; and a terrestrial system of the terrestrial time provider site, comprising a physical fiber that transmits a first time signal as an optical signal directly between a first patch panel local to the first time source and a second patch panel of the data center site hosting the computing system, wherein the computing system is configured to: receive, via the terrestrial system, the first time signal; receive, via a GPS receiver of the data center site, a second time signal originating from the first time source; compare a time obtained from the first time signal to a time obtained from the second time signal over a time period; perform an action related to one or more of the first time signal or the second time signal; and provide a timing service via a software-defined interconnection configured in a cloud fabric of the data center site to one or more client devices based on the action and one or more of the first time signal or the second time signal.
12 . The time synchronization system of claim 11 , wherein the physical fiber comprises a wave circuit, the wave circuit comprising a wavelength-division multiplexing (WDM), dense wavelength-division multiplexing (DWDM), or coarse wavelength-divisional multiplexing (CWDM) based wave circuit that transmits the first time signal as the optical signal.
13 . The time synchronization system of claim 11 , wherein to perform an action based on the comparison, the computing system is configured to: when the timing service uses the first time signal as a primary time source, switch to use the second time signal as the primary time source based on determining the first time signal is unreliable.
14 . The time synchronization system of claim 11 , wherein to perform an action based on the comparison, the computing system is configured to: when the timing service uses the second time signal as a primary time source, switch to use the first time signal as the primary time source based on determining the second time signal is unreliable.
15 . The time synchronization system of claim 11 , wherein to perform an action based on the comparison, the computing system is configured to: when the timing service uses the first time signal as a primary time source, output, for display, an indication of a quality of the first time signal based on the comparison.
16 . The time synchronization system of claim 11 , wherein to perform an action based on the comparison, the computing system is configured to: when the timing service uses the second time signal as a primary time source, output, for display, an indication of a quality of the second time signal based on the comparison.
17 . The time synchronization system of claim 11 , wherein to perform an action based on the comparison, the computing system is configured to: output an alert notification indicating a difference between the first time signal and the second time signal has crossed a predefined threshold.
18 . The time synchronization system of claim 11 , wherein the physical fiber comprises a first physical fiber, wherein the GPS system comprises a first GPS system, wherein the GPS receiver comprises a first GPS receiver, and wherein the comparison comprises a first comparison, the time synchronization system further comprising: a second physical fiber that transmits a third time signal as an optical signal directly between a third patch panel local to the second time source and a fourth patch panel local to the computing system, wherein the computing system is configured to: receive, via the terrestrial system, the third time signal; receive, via a second GPS receiver, a fourth time signal originating from the second time source; and compare a time obtained from the third time signal to a time obtained from the fourth time signal over a time period as a second comparison, wherein to perform an action the computing system is configured to perform, based on the first comparison and the second comparison, the action.
19 . The time synchronization system of claim 18 , wherein comparing the first time signal to the second time signal yields first difference information, and wherein comparing the third time signal to the fourth time signal yields second difference information, wherein the computing system is further configured to: compare the first difference information to the second difference information to obtain a delta, and wherein to perform the action the computing system is configured to perform the action based at least in part on the delta.
20 . Non-transitory computer-readable media comprising instructions that, when executed by processing circuitry, cause a computing system to: receive, via a terrestrial system, a first time signal originating from a first time source of a terrestrial time provider site, wherein the first time source is geographically distant from the computing system, and wherein the terrestrial system comprises a physical fiber that transmits the first time signal as an optical signal directly between a first patch panel local to a second time source and a second patch panel of a data center site hosting the computing system; receive, via a Global Positioning System (GPS) and a GPS receiver of the data center site, a second time signal originating from the first time source; compare a time obtained from the first time signal to a time obtained from the second time signal over a time period; perform, based on the comparison, an action related to one or more of the first time signal or the second time signal; and provide, via a software-defined interconnection configured in a cloud fabric of the data center site, a timing service to one or more client devices based on the action and one or more of the first time signal or the second time signal.

Description

This application claims the benefit of U.S. Provisional Patent No. 63/477,172, filed Dec. 23, 2022, the entire contents of which are incorporated by reference herein. TECHNICAL FIELD The disclosure relates to time synchronization in computer networks. BACKGROUND Every computing device has some form of clock inside. The crystals used inside these clocks are not expensive devices, but they drift, that is, they lose time due to various causes, such as temperature, humidity and the age of the device. Unless the devices on a network are periodically resynced, eventually, they will all be using a different time. Enterprise applications usually need to achieve 1 to 10 millisecond synchronization accuracy to avoid problems. Critical infrastructure may require 1-10 microseconds or sub-microsecond or even sub-nanosecond accuracy. To achieve these requirements, there must be a single, reliable source of time to which every device on a network can be synced. This has become especially difficult in hybrid cloud environments, where infrastructure is being deployed in private data centers and at the edge. A synchronization system, in general, synchronizes clocks of multiple secondary devices (also referred to as “slave” devices, “replica” devices, “follower” devices or “leaf nodes”) based on the clock of a chosen master device (also referred to as a “primary” device or a “leader” device). Primary devices are connected to the more precise sources of timestamps than secondary devices. The master device is a computing device that gets time synchronization data from other master devices or intelligent engines deployed either inside or outside of the synchronization system, such as a global positioning system (GPS). The typical synchronization system has one or more layers of master devices with secondary devices connected to at least one master device. In some implementations, master devices may belong to a service provider and can be designed to support precise time processing, while secondary devices may belong to the service client and receive timestamp offsets from master devices. These master and secondary devices can be chosen arbitrarily or assigned by the network. In many applications, including but not limited to financial, scientific, military, programmatic advertising, and gaming industries, time synchronization may be beneficial. For instance, such knowledge would be used to define trade orders in high-frequency trading systems and gamers' response in multi-user games. SUMMARY In general, the disclosure describes techniques and devices for integrating a terrestrial time feed with one or more computer networks also having a global positioning source (GPS)-based reference time feed to provide improved computing device clock synchronization. For example, the computer network may be a data center network, and a computing system in a data center network performs the time synchronization processes as described herein. In some examples, the data center network is configured to offer globally available timing services via a cloud fabric to customers across the world. In some examples, a method comprises receiving, by a computing system and via a terrestrial system, a first time signal originating from a first time source, wherein the first time source is geographically distant from the computing system, and wherein the terrestrial system comprises a physical fiber that transmits the first time signal as an optical signal on at least a portion of a path between the first time source and the computing system: receiving, by the computing system and via a Global Positioning System (GPS) and a GPS receiver, a second time signal originating from the first time source: comparing the first time signal to the second time signal over a time period; performing an action based on the comparison; and providing, by the computing system, a timing service to one or more client devices based on the action and one or more of the first time signal or the second time signal. In some examples, a time synchronization system comprises a first time source; a Global Positioning System (GPS): a computing system; and a terrestrial system comprising a physical fiber that transmits a first time signal as an optical signal on at least a portion of a path between the first time source and the computing system, wherein the computing system is configured to: receive, via the terrestrial system, the first time signal: receive, via a GPS receiver, a second time signal originating from the first time source: compare the first time signal to the second time signal over a time period: perform an action based on the comparison; and provide a timing service to one or more client devices based on the action and one or more of the first time signal or the second time signal. In some examples, non-transitory computer-readable media comprises instructions that, when executed by processing circuitry, cause a computing system to: receive, via a terrestrial system, a