Recommendation ITU-T G.8271.1/Y.1366.1 (2020) Network limits for time synchronization in packet networks with full timing support from the network Amendment 2 (02/2022)
Summary
History
FOREWORD
Table of Contents
Amendment 2
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 Network reference model
7 Network limits
     7.1 Network limits at reference point A
     7.2 Network limits at reference point B
     7.3 Network limits at reference point C
     7.4 Network limit at reference point D
     7.5 Network limits for deployment cases with the PRTC deployed in the access network
Appendix I  Clock models for noise accumulation simulations
     I.1 T-BC models for noise accumulation simulations
     I.2 End-to-end TC models for noise accumulation simulations
Appendix II  Hypothetical reference models used to derive the network limits
     II.1 HRM composed of T-BCs
          II.1.1 HRM without physical layer frequency support from the network
          II.1.2 HRM with physical layer frequency support from the network
          II.1.3 HRM for cluster-based synchronization
     II.2 HRM composed of T-BCs and T-TCs
          II.2.1 HRM with physical layer frequency support from the network
Appendix III  Network limits considerations
     III.1 Measurement of network limits in deployment case 1
Appendix IV  Constant and dynamic time error and error accumulation
     IV.1 Introduction
     IV.2 Components of time error
     IV.3 Accumulation of time error in a chain of clocks
Appendix V  Example of design options
     V.1 Network limits
     V.2 Components of time error budgets
     V.3 Failure scenarios
     V.4 Time error budget allocation
     V.5 Operator options
     V.6 Further details
Appendix VI  Mitigation of time error due to synchronous Ethernet transients
Appendix VII  Maximum relative time error
Appendix VIII  Models for budgeting in a chain of microwave devices
Appendix IX  Models for budgeting in a chain of xPON or xDSL devices
Appendix X  Time error and transients due to PTP rearrangement
Appendix XI  Measurement of maximum relative time error limits
     XI.1 Measurement of maximum relative time error limits
          XI.1.1 Measurement in a laboratory environment
          XI.1.2 Measurement in a field environment
          XI.1.3 Measurement in a field environment using radio signals
     XI.2 Estimation of maximum absolute relative time error
Appendix XII  Examples of design options for fronthaul and clusters of base stations
     XII.1 Requirements
     XII.2 Fronthaul architectures for packet-based time/phase distribution
     XII.3 Failure scenarios
     XII.4 Synchronization options
     XII.5 Relative time error budget allocation
     XII.6 Network design guidelines and measurement of the network limits
Bibliography
<\pre>