Effects of propagation path loss on the quality of VoIP over wireless mesh networks

In this paper, the effects of propagation path loss and hop count on VoIP over wireless mesh networks are shown. Simulation results for a linear chain topology 802.11s wireless mesh networks show that VoIP quality considerably decreases with the increasing hop count. Assuming free space propagation loss, if we increase the hop count, we observe that the number of supported 64 Kbps constant bit rate channels is at most 12 for 10 hops. Increasing the path loss exponent, n=2.7, we observe that 6 channels supported for a hop count of 6. If we further increase the path loss exponent to 3, for a hop count 3, 7 channels are supported. The hop count and propagation path loss considerably limits the VoIP quality and supported channel numbers. These effects should be considered during the design of wireless mesh networks.