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     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     
 8     High-accuracy time transfer              
        8.1     Introduction 
        8.2     Performance requirements   
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.2     HRM composed of T-BCs and T-TCs      
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.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     
Appendix XIII – High-accuracy time transfer    
     XIII.1     Use-cases     
     XIII.2     Optical components and compensation           
     XIII.3     External interfaces at HA-TT-Source and HA-TT-Sink:  
     XIII.4     Reference chain:        
Bibliography