Recommendation ITU-T G.8273.4/Y.1368.4 Amendment 1 (05/2021) Timing Characteristics of Telecom Boundary Clocks and Telecom Time Slave Clocks for Use with Partial Timing Support from the Network
Summary
History
FOREWORD
Table of Contents
1 Scope
2 References
3 Definitions
     3.1 Terms defined elsewhere
     3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 Physical layer frequency performance requirements
7 Performance requirements for T-BC-A and T-TSC-A
     7.1 Frequency accuracy
     7.2 Time error noise generation
          7.2.1 Maximum absolute time error (max|TE|) noise generation
          7.2.2 Constant time error generation
          7.2.3 Dynamic time error low-pass filtered noise generation
          7.2.4 Dynamic time error high-pass filtered noise generation
     7.3 Noise tolerance
     7.4 Local time reference (1PPS) to PTP and local time reference (1PPS) to 1PPS noise transfer
     7.5 PTP output and 1PPS output transient response (short term) due to loss and restoration of local time reference (1PPS) input
     7.6 Holdover performance
          7.6.1 Holdover based on oscillator
          7.6.2 Holdover based on PTP
8 Performance requirements for T-BC-P and T-TSC-P
     8.1 Frequency accuracy
     8.2 Time error noise generation
          8.2.1 Maximum absolute time error noise generation (max|TE|)
          8.2.2 Constant time error noise generation
          8.2.3 Dynamic time error low-pass filtered noise generation
          8.2.4 Dynamic time error high-pass filtered noise generation
     8.3 Noise tolerance
     8.4 Noise transfer
          8.4.1 PTP to PTP and PTP to 1PPS noise transfer
          8.4.2 Physical layer frequency assistance to PTP and physical layer frequency assistance to 1PPS noise transfer
     8.5 Transient response (short-term)
          8.5.1 PTP output and 1PPS output transient response due to loss and restoration or switching of PTP input
          8.5.2 PTP output and 1PPS output transient response due to switching physical layer input while maintaining PTP input
          8.5.3 PTP output and 1PPS output transient response due to switching simultaneously the physical layer input and the PTP input
     8.6 Holdover performance
          8.6.1 Holdover based on oscillator
          8.6.2 Holdover based on physical layer frequency assistance
9 Interfaces
     9.1 Phase and time interfaces
     9.2 Frequency interfaces
Annex A  T-TSC-A and T-BC-A functional model
Annex B  T-TSC-P and T-BC-P functional model
Appendix I  Consideration of slave clocks embedded in end applications
Appendix II  Consideration of variable temperature testing
Appendix III  Consideration of the use of a synchronous equipment clock to maintain  time holdover for partial timing support networks
Appendix IV  Use of a synchronous equipment clock to assist a PTP time lock
Appendix V  Synchronization interworking function P-F node limits
Appendix VI  PTP Noise Tolerance Testing for PTS and APTS Clocks
     VI.1 Testing set-up for PTP noise tolerance testing
     VI.2 Statistical PDV model
     VI.3 Parameters for the PDV model
     VI.4 Different requirements for APTS and PTS models
          VI.4.1 APTS pattern generation
          VI.4.2 PTS pattern generation
     VI.5 Example delay patterns
     VI.6 Output requirements
Bibliography
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