Investigating the Performance of Video-on-Demand Systems over WLANs Using Generic Association Control ⋆

Abstract. The problem of scalable video-on-demand (VoD) delivery has been extensively studied over the past years, in the context of wired networks. As VoD-based applications are gaining more and more attention, there is an increasing need of ubiquitous access for them. Wireless networks can be the answer to this need. However, the system behind the application must be scalable to deal with a growing amount of simultaneous accesses, while guaranteeing QoS. Thus the performance of VoD systems must be revisited in this new context, especially aiming scalability. In this paper, we present a preliminary study of a system-level design for VoD systems that operate over 802.11 networks, where commodity Access Points (APs) work collocated in no-overlapping channels which are orchestrated by a central entity that is responsible for controlling the association of clients to the APs. The simulation conducted demonstrates that our system design, using the generic least loaded first heuristic, can use the full aggregate bandwidth as collocated APs allow to. Despite the effective use of bandwidth, it achieved a low blockage rate only for short-length videos at low arrival rates, and performed poorly when video length and arrival rate grow.