Downlink performance analysis for broadband wireless systems with multiple packet sizes

Broadband wireless systems are becoming very popular today and several networks and technologies are available. The focus is here on radio resources of OFDM(A)-based air interfaces, such as WiMAX and LTE. A preliminary investigation has permitted to highlight what a ‘resource’ means. Then, this paper compares different analytical frameworks (for cases with and without MAC layer fragmentation), which are suitable for downlink performance evaluation in packet-switched broadband wireless systems. This study is carried out for a single traffic class, considering that bb resources can be allocated on a ‘frame’ basis and that packets have a variable size. Simulation results have been shown to be in good agreement with theoretical results. Finally, a selected analytical method has been applied to a fixed WiMAX cell planning example (considering different IP packet lengths and the use of several modulation and coding combinations), showing the potentialities of this approach.