Audio communication in multicast 802.11 vehicular ad hoc networks for safety applications

Abstract

In this paper we analyze the performance of multimedia communication in a Vehicular Ad hoc Network (VANET). We focus on the multicast transmission of multimedia signals (MP3 streams) between a static and a mobile node. We examine different solutions to guarantee vehicle-toinfrastructure connectivity via both omni-directional and directional antennas. An optimized client-server streaming software suite has been developed and tested with various safety messages in a real-world network testbed. Results are presented in terms of both network layer (such as packet loss rate) and application layer (Mean Opinion Score) metrics. Results show that the network and application layer QoS are strictly related to the specific context of the experiment (environmental conditions, selected hardware). Results also show that a reasoned choice of the hardware makes possible to transmit multicast safety messages in urban context using the standard 802.11b protocol.