Design of Load-based Power Saving and Scheduling Scheme Integrating Real-time and Non-real-time Services in WiMAX Networks

There are three types of power saving classes in the specification of IEEE 802.16e/m: Type I, II, and III. Most of the researches focused mainly on Type I or Type II, which means these previous works could also inherit the limitation of how to select the sleeping pattern in Type I and Type II: either adopting the exponential pattern of Type I or adopting the constant pattern of Type II for the sleep window size. In our previous research, we discussed the limitation of adopting Type I or Type II, and had brought up the idea of applying traffic modeling and measurement called Load-Based Power Saving (LBPS). Poisson process is adopted to simplify LBPS for traffic modeling. The objective of LBPS is to adaptively adjust the sleep window size of each MSS to better fit in the current traffic (load) condition by traffic measurement. To consider both real-time and non-real-time traffic characteristics, a new LBPS scheme, namely LBPS-RT, is proposed in this paper to effectively schedule traffic and support the traffic delay requirement. Simulation results demonstrate that better power-saving efficiency can be achieved by the LBPS-RT than the standard Type I and II. In addition, the delay bound requirement can be achieved in our new LBPS-RT scheme.