ITU-T G.8272.1 (ePRTC) One-Page Summary
Title: Timing characteristics of enhanced primary reference time clocks
Summary
Enhanced Primary Reference Time Clock equipment specification
Provides an accurate time reference into the network, using a 1pps output port
Typical implementation based on GNSS
Jitter/wander based on Enhanced PRC specification (G.811.1)
Status
Current version: 2.1 Edition, July 2025, Amendment 1 to 2024 Revision
Download from: http://www.itu.int/ITU-T/recommendations/rec.aspx?rec=13162
Enhancements in progress: addition of a PTP time output port
Key Contents
Time Accuracy
While locked to GNSS, with clear sky view: within 30ns of UTC
In holdover: within 100ns of UTC for up to 40 days (it depends on locked mode period)
Functional Model
Wander
Holdover
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