Traffic Channel 

  Carries either encoded speech or user data up and down link between a single 

     mobile and a single BTS. 

Types of traffic channel:  

 *  Full rate (TCH)   

       Transmits full rate speech (13 Kbits/s). A full rate TCH occupies 

          one physical channel. 

 *  Half rate (TCH/2)    

       Transmits half rate speech (6.5 Kbits/s). 

       Two half rate TCH’s can share one physical channel, thus doubling the capacity 

          of a cell.