CONTENTS

 1     Scope and purpose      
 2     References
 3     Definitions    
 4     Abbreviations 
 5     Reference configuration 
 6     Need of protection      
 7     Probabilistic analysis    
        7.1     Tolerable frequency of damage (Ft)       
        7.2     Frequency of strikes to the tower (Fa)   
        7.3     Frequency of strikes to the RBS housing (Fd)   
        7.4     Analysis of the frequency of strikes     
 8     Determination of the lightning current parameters      
 9     Protection procedures in LPZ0 
        9.1     Procedures applied to the tower 
        9.2     Earthing system  
10     Protection procedures for the cables that come from the tower        
11     Protection against the lightning effects inside the housing     
       11.1     Shielding factor (h)       
       11.2     Mesh-BN configuration 
       11.3     Mesh-IBN configuration
       11.4     Protection procedures at the boundary between LPZ1 and LPZ2      
12     Protection against the lightning effects at the services entrances       
       12.1     Power service    
       12.2     Telecommunication service      
Annex A – Factor for current distribution along a tower (a)    
        A.1     Tubular tower    
        A.2     Three legs tower 
        A.3     Four legs tower  
Annex B – Shielding factor (h) for CBN loops     
Annex C – Transfer factor (b) for cable trays and earth conductors    
        C.1     Single earth conductor    
        C.2     Double earth conductors 
        C.3     Earth plate tray  
Annex D – Geometric mean radius    
Appendix I – Rationale for effective front time    
Appendix II – Example of application