Impact of Medium Access Control Strategies on the Effectiveness of Advanced Cooperative Hybrid ARQ Techniques

This paper explores the relationship between cooperation and two very different medium access strategies: CSMA (epitomized by IEEE 802.11 DCF) and one instance of TDMA (represented by IEEE 802.15.3). By cooperation we mean basic decode-and-forward relaying as well as more advanced forms thereof based on network coding. The essential features that make each system more or less suitable to support the potentially high performance gains of hybrid ARQ are analyzed and studied by means of extensive simulations. The discussion carried out in this paper shows that centralized systems are able to reap far higher gains from a cooperative paradigm than their distributed counterparts, and investigates in depth the reasons that lead to such different behaviors, prompting also some interesting insights for proper design of advanced hybrid ARQ protocols.