Ad-hoc voice-based group communication

People waste many hours driving each day. Although unavoidable, this time can be very boring to motorists. Similar to people taking mass transit who often pass the time socializing with those around them, motorists could benefit from social interactions if they were given broader social opportunities. Unfortunately, existing Multiparty Voice Communication (MVC) systems do not scale to large numbers of users and do not provide adequate access controls. We present RoadSpeak, a scalable MVC system that allows motorists to automatically join Voice Chat Groups (VCGs) along popular roadways. RoadSpeak achieves interruption-free communication through the use of voice chat message buffering, flow control and in-order delivery of voice messages to participants. We have implemented a RoadSpeak prototype on Nokia N95 smart phones using 3G cellular networking for voice message transfer. We have also built an MVC simulator to perform large-scale simulations that compare RoadSpeak with existing MVC systems. The results of our evaluation prove the feasibility of RoadSpeak and demonstrate that it performs similarly to a traditional MVC systems while supporting substantially larger groups of users.