ITU-T G.8263 (Packet-Based Slave Clock Performance) One-Page Summary
Title:Â Timing characteristics of packet-based equipment clocks (frequency)
On this page:
Summary
Packet-Based Equipment Slave Clock for Frequency (PEC-S-F)
Designed primarily to supply frequency to cellular basestations
Target output performance requirement: 16ppb frequency accuracy
Specifies frequency accuracy, noise generation, noise tolerance, holdover, testing methods
Status
- Current version: 2nd. Edition, August 2017
- Download from: http://www.itu.int/ITU-T/recommendations/rec.aspx?rec=13320
Key Contents
- Frequency accuracy (free-run): 4.6 ppm
- Noise (wander) Generation:
- Noise (PDV) Tolerance:
- Holdover: based on G.812 Type III clock (Stratum 3E)
- Testing methods: Appendix I describes three methods of measuring the performance of slave clock:
- PDV patterns based on flicker noise
Measures clock performance using input PDV containing equal energy in every decade of
frequency (i.e. flicker noise) - PDV patterns based on combined sinusoidal waveforms
Measures clock performance using input PDV containing multiple frequencies simultaneously - PDV patterns based on a single sinusoidal waveforms
Measures clock performance using PDV containing a sinusoidal modulation of the floor delay
- PDV patterns based on flicker noise