Automatic repeat request (ARQ) schemes are effective to recover non-real-time data corrupted by channel errors, but their use with real-time traffic is seldom considered because packet retransmissions tend to increase the delay beyond the deadline. However, the high-speed of modern wireless local area networks, together with their inherent low propagation times, favors the use of ARQ schemes with real-time traffic. This paper proposes a fast retransmission scheduling mechanism for reliable transport of realtime traffic in HIPERLAN/2 systems, as well as an adaptive rate scheme designed to reduce the delay introduced by retransmissions while keeping the same level of network efficiency. The achieved performance is evaluated in the scenario of a distributed data acquisition and control system.
Jose A. Afonso, Joaquim E. Neves