GdotWhat?


Welcome to GdotWhat?

Your guide to Sync standards and how to interpret them


Various Standardization Development Organizations (SDOs) have been working at standards dealing with synchronisation.

Within Telecoms, the main group dealing with synchronisation is Question 13 in ITU-T SG15. Starting from end application requirements as defined for instance by 3GPP for mobile applications, over the years Q13 has delivered a number of Recommendations dealing with network synchronization solutions, network synchronisation performance requirements, clock performance, PTP (Precision Time Protocol) telecom profiles.

PTP (Precision Time Protocol) has been specified by IEEE 1588 WG. P1588 WG is working at several Amendments to the IEEE1588-2019 Standard.

Several other IEEE WGs are working at synchronisation. In particular, IEEE 802.1 WG has developed and is maintaining IEEE 802.1AS Standard, Timing and Synchronization for Time-Sensitive Applications. This is a PTP profile that can be used for Industrial Automation or Automotive applications.

The O-RAN Alliance has developed a number of synchronization specifications related to the open radio access network.

Right now, we mainly cover the ITU-T and O-RAN Standards. We will be adding material from other standards bodies in the near future.

An overview on O-RAN synchronization is available in the O-RAN Synchronization page. The starting point for learning about the ITU-T synchronisation standards is ITU-T Packet-Based Synchronisation - A Guide to the Synchronisation Standards.

Alternatively, you can search for the content you want using the search bar below, go directly to the topic you want from the list of featured pages or browse the table of contents to see what is available.


Contents

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Study Group 15

Key:Device TestNetwork Test
What are you testing?StandardTechnical OverviewTest Guide

GeneralCX7006PTP Profile Compliance: The key to network timing interoperability

CX5013Time and Time Error, A Guide to Network Synchronisation


Interpretation of Time Error Results

Frequency Network LimitsG.8261.1

CX5018Sentinel Field Test Plan for Frequency Synchronisation using PTP
SyncE Clock


G.8262


CX3002Jitter and Wander in SyncE: Testing Jitter and Wander to ITU-T StandardsCX5001G.8262 SyncE conformance testing: Proving SyncE compliance to ITU-T G.8262 using Paragon-X

CX8010  

The importance of measuring wander on high speed interfaces

CX5026

Testing EECs to ITU-T G.8262 using Paragon-100G

Time and Phase Network LimitsG.8271.1

CX5019Sentinel Field Test Plan for TDD-LTTE/LTE-A Synchronisation using PTP
G.8271.2

CX4005Sentinel Field Test Plan for TDD-LTE/LTE-A Synchronisation in Systems using Assisted Partial Timing Support and Partial Timing Support
Boundary and Slave ClockG.8273.2



CX6001

Testing a T-BC to ITU-T G.8273.2

CX5008

 T-BC Time Error: Testing Boundary Clocks to ITU-T G.8273.2 using Paragon-X

CX6002Measuring Time Error Transfer of G.8273.2 T-BCsCX3003PTP Time Error for T-BC: Testing Boundary Clocks to ITU-T G.8273.2 using Paragon-100G


CX5020T-TSC Time Error: Testing Time Slave Clocks to ITU-T G.8273.2 using Paragon-X
Transparent ClockG.8273.3

CX5021T-TC Time Error: Testing Transparent Clocks to ITU-T G.8273.3 using Paragon-X
Time-Aware RelayIEEE802.1AS (gPTP)

CX7005

gPTP: Proving Time Accuracy for Automotive SystemsCX5030

 Time Aware Relay: Time Error Testing using Paragon-X

CX7003gPTP: Testing Synchronisation for Industrial TSN