Analysis of energy consumption of IEEE 802.11 DCF under non-saturation conditions

We develop an analytic model to evaluate non-saturation energy consumption of IEEE 802.11 DCF, based on the model in G.R. Cantieni et al., (2005). The model explicitly takes into account both the carrier sensing mechanism and an additional backoff interval after successful frame transmission, which can be ignored under saturation conditions. The probability generating function with respect to energy consumed between consecutive frame generations is derived. Numerical example shows that most of the energy is wasted in carrier sensing when the frame generation probability is smaller than some critical value and that the energy consumed in overhearing a frame destined to another user occupies the major part otherwise.