RANDOM-ACCESS WITH LARGE PROPAGATION DELAY

Random access to a packet broadcast channel with large propagation del ay is investigated, A protocol is presented that combines slotted ALOH A random access with the use of forward-error-correction (FEC) across transmitted packets, Expressions for the throughput, delay, and drift of this protocol are derived, Numerical studies and asymptotic analyse s of the drift indicate that the protocol has a maximum throughput of e(-1) and exhibits bistability and saturation behavior similar to that of slotted ALOHA with immediate feedback. However, unlike ALOHA, bist ability and saturation in the code protocol can be eliminated with the proper choice of protocol parameters without increasing the packet de lay, It is further shown that, when compared to slotted ALOHA, the cod e protocol typically achieves a higher throughput and lower delay at s ystem equilibrium with no loss in maximum throughput.