New point-to-multipoint communication protocols

Two link-control protocols, termed hybrid go-back-N (HGB-N) and hybrid selective-repeat (HSR), for point-to-multipoint communication over broadcast links, are proposed and analysed. Both protocols incorporate a concatenated coding scheme for error correction and error detection. An analytic expression is derived for the throughput efficiency of the HSR protocol, while computer simulation is used to evaluate the throughput efficiency of the HGB-N protocol. The proposed point-to-point hybrid protocols provide satisfactory throughput and perform considerably better than the corresponding basic protocols in which a block code is used for error detection only, especially in environments with a large number of receivers and large link round-trip delays, such as satellite broadcast links.