Performance evaluation

layers of WiMAX networks. A critical part of the MAC layer specification is packet scheduling, which based on a fixed data rate requested by subscriber stations (SSs) of the UGS class. The IEEE 802.16e-2005 [2] standard introduces an additional scheduling service, extended real-time polling ser-vice (ertPS), which builds on the efficiency of both UGS and rtPS. Just like the UGS class, the BS is allowed to provide unicast grants to the ertPS SSs, but the size of the grants can vary, enabling a more efficient usage of available bandwidth. Despite the numerous scheduling algorithms proposed for Wi-MAX networks, there is no comprehensive study that provides a unified platform for comparing such algorithms. The aim of this work is to allow a thorough understanding of the relative perfor-mance of representative uplink scheduling schemes and subse-quently utilize the results to address their scarcity in designing more efficient schemes. We focus our work on implementing rep-resentative algorithms for the uplink traffic in OFDMWiMAX phys-ical layer using network simulator 2 (NS-2). Another major contribution of this work is evaluating the algorithms using traffic models specifically designed for WiMAX to represent its diverse * Corresponding author