Trade-off analysis of PHY-aware MAC in low-rate low-power UWB networks

We are interested in the design of physical-layer-aware medium access control for self-organized low-power low-data-rate impulse radio ultra-wideband (IR-UWB) networks. In such networks energy consumption is much more of a concern than achieved data rates. So far, a number of different solutions have been proposed in the context of data rate efficiency for IR-UWB. However, the choices made for rate-efficient designs are not necessarily optimal when considering energy efficiency. Hence, there is a need to understand the design trade-offs in very low-power networks, which is the aim of this article. To this end, we first identify what a PHY-aware MAC design has to achieve: interference management, access to a destination, and sleep cycle management. Second, we analyze how these functions can be implemented, and provide a list of the many possible building blocks that have been proposed in the literature. Third, we use this classification to analyze fundamental design choices. We propose a method for evaluating energy consumption already in the design phase of IR-UWB systems. Last, we apply this methodology and derive a set of guidelines; they can be used by system architects to orientate fundamental choices early in the design process.