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     Reference models 
        5.1     General            
        5.2     Downstream vectoring              
        5.3     Upstream vectoring    
 6     CO-side requirements in a vectored group 
        6.1     General            
        6.2     Downstream vectoring requirements for the VTU-O   
        6.3     Upstream vectoring requirements for the VTU-O         
        6.4     Requirements for the VCE       
 7     CP-side requirements in a vectored group  
        7.1     General            
        7.2     Downstream vectoring requirements for the VTU-R    
        7.3     Upstream vectoring requirements for the VTU-R          
        7.4     Requirements for the NT system          
 8     Vectoring-specific eoc messages     
        8.1     eoc messages for backchannel configuration  
        8.2     Pilot sequence update command and response            
        8.3     Power management commands and responses            
 9     Activation and deactivation of pairs in a vectored group       
        9.1     Orderly shutdown event          
        9.2     Disorderly shutdown event     
10     Initialization of a vectored group    
       10.1     Overview       
       10.2     ITU-T G.994.1 Handshake phase          
       10.3     Channel Discovery phase        
       10.4     Training phase             
       10.5     Channel Analysis and Exchange phase              
       10.6     Transition from initialization to Showtime        
       10.7     Loop diagnostic mode procedures      
11     Configuration and test parameters
       11.1     Configuration parameters      
       11.2     Test parameters         
Appendix I – Crosstalk channel modelling    
        I.1     Scope 
        I.2     Purpose            
        I.3     MIMO crosstalk channel model A          
        I.4     MIMO crosstalk channel model C          
Appendix II – Examples of VCE control of initialization process in the activation of multiple lines in the vectored group    
       II.1     Introduction   
       II.2     VCE handling two groups of initializing lines      
       II.3     VCE using handshake capabilities          
Appendix III – SNR-based FEXT channel estimation method    
      III.1     Tools  
      III.2     Estimation of FEXT channels from a new line into existing lines
      III.3     Estimation of FEXT channels from existing lines into a new line
Bibliography