Write about maximum number of frequency channels per cell

8. Write about maximum number of frequency channels per cell.

The maximum number of frequency channels per cell N is closely related to an average calling time in the system. The standard user’s calling habits may change as a result of the charging rate of the system and the general income profile of the users If an average calling time T is 1.76 min and the maximum calls per hour per cell is Qi, then the offered load can be derived as

A = Qi*T/60 (Erlangs)

If the blocking probability is given, then it is easy to find the required number of radios in each cell. If a large area is covered by 28 cells, Kt = 28; the total number of customers in the system increases. Therefore, we may assume that the number of subscribers per cell Mi is somehow related to the percentage of car phones used in the busy hours and the number of calls per hour per cell Qi as

Where the value Qi is a function of the blocking probability B, the average calling time T, and the number of channels N.

Qi= f(B, T, N)

If the K = 7 frequency reuse pattern is used, the total number of required channels in the system is 

Nt = 7 X N.