VoIPiggy: Implementation and evaluation of a mechanism to boost voice capacity in 802.11 WLANs

Abstract

Supporting voice traffic in existing WLANs results extremely inefficient, given the large overheads of the protocol operation and the need to prioritize this traffic over, e.g., bulky transfers. In this thesis we propose a simple scheme to improve the efficiency of WLANs when voice traffic is present. The mechanism is based on piggybacking voice frames from one direction of the voice call over the acknowledgments for the frames on the other direction, which reduces both frame overheads and time spent in contentions. We evaluate its performance by means of analysis and in a large-scale testbed consisting on 30 commercial off-the-shelf devices. The experimental results follow those from the analytical model, obtaining dramatic performance improvements in both voice-only and mixed voice-and-data scenarios.