The number of channel slots that can be provided in a TDMA system is found by multiplying the number of TDMA slots per channel by the number of channels available.
N = m (Bt -2 Bguard) / Bc
m = Maximum number of TDMA users supported on each radio channel
Bc = Channel bandwidth
Bt = Total specturm allocation
Bguard = Guard band allocated at the edge of allocated spectrum