Fundamentals of packet multiple access for satellite networks

The fundamental objectives which guide the design of a packet multiple-access technique for satellite networks with large numbers of earth stations are explained. Among these objectives are low peak power in the transmitters, low average power from the satellite transponder, high channel capacity, and low complexity of the multiple-access receiver. The author reviews the fundamentals of satellite packet multiple access and relates these fundamentals to the objectives listed. Code division multiple-access (CDMA) and ALOHA multiple access are described in terms of these fundamentals. A simple linear transformation of conventional ALOHA access, called spread ALOHA, is described. For the case of a low signal-to-noise ratio in the receiver and a low duty cycle of individual and identical transmitters, it is not possible to find a multiple-access method at the same average power and are the same bandwidth which is more efficient than spread ALOHA