Hybrid ARQ protocol for real-time ATM services in broadband radio access networks

We propose a new type of hybrid ARQ protocol, in which the channel-adaptive variable rate channel coding scheme is combined with the multi-copy retransmission strategy so as to optimize the system performance under the delay constraint of real-time ATM services in broadband radio access networks. The main feature of the multi-copy retransmission strategy in this scheme is to maximize the average throughput for the given FEC rate subject to the prescribed cell loss requirement of the real-time wireless ATM services while augmenting the reliability of slow channel state estimation process required for the channel-adaptive FEC scheme. The analysis shows that under a harsh fading channel, the proposed approach is useful for achieving the prescribed cell loss performance without significantly degrading the average throughput