Performance Study of Power Saving Classes of Type I and II in IEEE 802.16e

The IEEE 802.16e standard introduces two types of sleep modes which perform very differently under different traffic types: power saving classes of type I based on binary-increasing sleep window size and power saving of type II using constant sleep window size. This paper provides simple but accurate analytical models capable of calculating the power efficiency and packet access delay for the two power saving types. In addition, a comparison of the energy efficiency and delay performance between the two power saving types is reported. By means of the proposed model and evaluation, we point out the trade-off between these two types and suggest a power switching scheme to obtain optimal power efficiency under different traffic conditions. Numerical and simulation results are provided for validation of our models