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