Energy consumption (J/MB) in 802.11 networks

The paper derives formulas for the energy J(n) that a station’s radio consumes in order to transmit 1 MB of data in an IEEE 802.11 network with n stations. Calculations show that J(n) grows approximately linearly with n, for n ≥ 4. The useful energy consumed in successful transmission and reception of data is constant; the remaining energy is wasted. When n = 15, the waste amounts to 80 percent of total energy, and this proportion grows with n. More than 60 percent of the waste is due to overhearing, i.e. reception of packets intended for another station. Overhearing can be eliminated by using information in RTS/CTS packets.