Decision of mobile devices enabling HT and non-HT MAC of 802.11n based on the consideration of energy efficiency

In order to be compatible with the legacy 802.11, there are two major MAC behaviors, High-throughput (HT) and non-high throughput (non-HT) in the 802.11n. In this paper, we analyze and compare the energy efficiencies of different MAC behaviors in 802.11n based on the Bianchi model and our previous works [6] to evaluate the performance of the different MAC behaviors regarding HT and non-HT. Our studies try to provide the decision for the mobile devices stations to enable the HT or not based on the consideration of energy efficiency. Studies show that owing to the large power consumption in HT, it is not suitable for limited power devices to carry WWW traffics by MIMO transmission. However, if large file transmissions by FTP are considered, the energy efficiency in HT MAC can be very high due to the large aggregated frame size. It is especially true when the number of active stations is large owing to the decrease in idle listening time by using the techniques used in HT MAC such as Aggregate MAC protocol Data Unit (A-MPDU) and block-ACK.