Design and Implementation of Audio Conferencing Testbed based on Wi-Fi MANET

Based on the technology of Mobile Ad-hoc Network (MANET), we design and implement an Audio Conferencing Testbed (ACT) that is used for a group of people to set up virtual audio conferencing room to complete certain mission in places where network infrastructure is unavailable. ACT is built on popular Windows operating system with off-the-shelf IEEE802.11 (a.k.a. Wi-Fi) adapters as the enabling technology. Little assumption is made during the development process in order to minimize the gap between a laboratory testbed and a fully-operational system. Some notable features of ACT include: 1) it makes use of distributed TDMA scheme to provide "circuit-switched" type of Quality-of-Service (QoS) guarantee for audio traffic; 2) its broadcast tree building algorithm is able to minimize the latency of message dissemination to the whole network; 3) the protocol running in ACT is able to predict radio link break due to mobility so that service interruption is reduced; 4) and relative position information is available at each node in the network. Our work is focused on the system aspect, and a series of experiments are conducted in real environment to verify the system design and evaluate its performance.