ITU-T G.8263 (Packet-Based Slave Clock Performance) One-Page Summary

Title: 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

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