On energy consumption of Wi-Fi Access Points

With the recent trends towards green communications, several companies introduced low-power Wi-Fi products targeting application domains such as smart grid utilities, home and building automation, healthcare etc. However, Wi-Fi Routers/Access Points (AP) have not been targeted much so far as they are mains-powered and are “always-on” devices. A wireless LAN extension to an existing wired fire alarm system requires the Wi-Fi AP to be powered by the bus where energy might be limited depending on the number of peripherals on the same bus. Moreover, regulations require battery backup power for each device on the bus. In order to better understand the feasibility of such system, we studied the energy consumption of two selected consumer grade APs with different hardware and software architectures. Our study discusses about the contribution of the components on the AP to the overall energy consumption. Furthermore, we investigate the impact of different traffic patterns, data rates, packet sizes, security schemes, number of clients etc., on AP energy usage and analyze the results.