Experimental Study of Voice Over IP Services Over Broadband Wireless Networks

In this paper, a hybrid network consisting of both WiMAX and WiFi links is set up and used as a testbed for Voice-over-IP (VoIP) performance studies. Relevant metrics are defined and used to analyze the performance of this hybrid network and its ability to support VoIP calls. End-to-end delay and packets loss are measured as a function of number of ongoing VoIP calls. Based on these measured results, the authors propose a procedure to evaluate the maximum number of ongoing calls can be supported by the hybrid network while maintain the call quality at the desired level using the ITU-T specified E-model.