Design and demonstration of live audio and video over multihop wireless ad hoc networks

Abstract

An ad hoc network is a collection of mobile nodes using wireless network interfaces to communicate among themselves, discovering and routing along possibly multihop routes to each other without the assistance of fixed infrastructure. In this paper we describe the design and demonstration of a set of simple routing protocol mechanisms that substantially improve the transmission of real-time multimedia streams over a multihop wireless mobile ad hoc network. The public demonstration of these mechanisms at the final DARPA GloMo PI meeting showed smooth audio and clear video over the ad hoc network throughout the demonstration, despite frequent routing changes taking place as a car implementing one endpoint node moved continuously. We implemented our routing extensions in the dynamic source routing protocol (DSR) running over standard 2 Mbit/s Lucent WaveLAN-II radios; the two endpoint nodes ran standard Microsoft Windows NetMeeting, communicating entirely through normal IP packets over our 8-node DSR ad hoc network.