A context-aware approach to wireless transmission adaptation

Recent advancements in wireless transmission have enabled networks with a high level of physical layer flexibility. Unfortunately, these new opportunities are not harnessed by modern wireless systems. Due to inefficient resource allocation, systems typically encounter problems such as spectrum scarcity, energy depletion or low quality of service. In this paper we consider the problem of physical layer parameter adaptation in a flexible wireless system. We observe that for many practical purposes the acceptable quality of communication depends on the interplay among the packet loss ratio, energy savings and spectrum utilization. We harness this fact and propose a context-aware physical layer parameter adaptation solution, WhiteRate. Our solution adjusts the modulation level, coding scheme and channel width to achieve the communication profile that matches application requirements. We implement WhiteRate in GNUradio and evaluate it in both indoor and outdoor environments. We demonstrate improvements on two important fronts: spectrum utilization and energy efficiency. Moreover, we show that by using WhiteRate, both benefits can be achieved simultaneously.