DECENTRALIZED CONTROL IN PACKET SWITCHED SATELLITE COMMUNICATION

The problem of access control to a packet switched multiaccess satellite broadcast channel is considered in the framework of nonclassical control theory. This viewpoint, with the simple model presented, gives us some interesting results. It is shown under certain assumptions, that because of the inherent delay in information, the optimal control law will be within the class of open loop control laws. By a result in Bayesian decision theory it is shown that randomized decisions will not be necessary. Given an additional minor restriction we find that for “new” packets only two modes of operation of the channel could be optimal, namely, All Together (every station sends whenever it has a packet) or Round Robin (every station sends whenever it is its turn and it has a packet), and an equation for the crossover arrival probability Po at which tbe ehaanel would switch from All Together (p <Po) to Round Robin (p> Po) is given. For collided packets we find that it is optimal to have predetermined assignments of groups of stations to time slots for retransmissions, and a dynamic programming algorithm for determining the optimal grouping is given. © 1978 IEEE