Optimal Preamble Sampling for Low Power Wireless Networks

Preamble sampling (or low-power listening) is a low-power technique used in wireless networks to allow nodes to check for waiting traffic by periodically waking up from a low-power sleep state. An increasing number of proposals exist in literature to provide static and adaptive solutions to implement preamble sampling. This paper tackles the important question of what is the optimal preamble sampling period in a multi-node wireless environment. Expressions are derived for the optimal sampling period for both contention-based and non-contention-based medium access schemes and the accompanying energy consumption analysis is provided. This work clearly identifies the optimal sampling period to achieve minimum energy consumption on a per node basis as a function of the size of the neighborhood, the packet arrival rate, the parameters of the preamble sampling scheme and accompanying medium access scheme, and the device parameters of the wireless node. Simulation results are included to support the findings.