On the Performance Gains of VoIP Aggregation and ROHC over a WirelessMAN-OFDMA Air Interface

A growing number of mobile WiMAX deployments are in progress world-wide and the technology is anticipated to play a key role in next generation mobile broadband wireless networks. However, although the theoretical potential of WiMAX technologies is already well established, independent, publicly released, thorough evaluations of WiMAX network performance in the real world are yet to become available. In this study, we consider synthetic voice over IP (VoIP) performance over the wirelessMAN-OFDMA air interface of a state of the art mobile WiMAX testbed operating at the 3.5 GHz frequency band and quantify the benefits of employing VoIP aggregation and robust header compression (ROHC). Although VoIP aggregation and ROHC have been proposed and thoroughly evaluated through simulation and modeling, this is the first study to present empirical results from employing them over the wirelessMAN-OFDMA air interface of a real-world WiMAX system. Our results indicate that the combined use of VoIP aggregation and ROHC can increase the number of flows sustained without loss by approximately a factor of three.