The PAMA protocols are considered the most effective techniques for those satellite networks with a small number of terminals (for example, less than 10) having stable as well as predictable traffic patterns.
A PAMA protocol can be employed on a frequency, code, or time basis. Key techniques are Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), and Time Division Multiple Access (TDMA).
In PAMA, the capacity assignment is allocated in a fixed mode between various stations. The fluctuation in demand can result in considerable underuse of capacity.
On the contrary, in DAMA, the capacity assignment is modified as required to respond in a best way to demand modifications among the various stations.
Advantages of PAMA:
Perfect for constant-bit-rate-type sources
Channel usage is contention-free
Disadvantages of PAMA:
Considerable bandwidth usage
Not flexible while working with terminals having variable bit rates