Rate adaptation algorithms for reliable multicast transmissions in wireless LANs

The widespread utilization of wireless local area networks (WLANs) as the leading technology for delivering multimedia streams pushed IEEE to ratify the new 802.11aa amendment that enables reliable multicast transmissions over the air. The new feedback-based Group Addressed Transmission Services (GATS) also allows the development of innovative rate adaptation algorithms for multicast traffic; though not explicitly contemplated by the 11aa document, they are crucial in order to improve the overall network throughput. Nonetheless, their performance analysis on large-scale wireless networks results is impractical due to the lack of a unified simulation framework. To this end, we introduce in this chapter new extensions to Network Simulator (NS-2) for implementing GATS and we design a novel application programming interface (API) that permits us to seamlessly integrate new multicast rate adaptation mechanisms by exploiting GATS feedback. We first review the relevant literature on rate adaptation for multicast wireless networks. Then, we describe our unified framework integrated within NS-2 for simulating these algorithms in realistic network scenarios, detailing its internal architecture as well as the reference API. Finally, we provide some multicast rate adaptation algorithms developed using our framework and present their comparative evaluation, which demonstrates the validity of our solution.