CodePlay: Live multimedia streaming in VANETs using symbol-level network coding

Live multimedia streaming (LMS) services are important in vehicular ad hoc networks (VANETs) for their capability of providing comprehensive and user-friendly information. The fundamental challenges come from achieving stable and high streaming rate (smooth playback) for all the interested vehicles while using minimal bandwidth resources, especially under the highly dynamic topology of VANETs and the lossy nature of vehicular wireless communications. A recent technique, symbol-level network coding (SLNC), has been shown to be an effective approach to improve the efficiency of bandwidth utilization, by exploiting both wireless symbol-level diversity and the benefits of network coding. In this paper, we introduce CodePlay, a new LMS scheme in VANETs that fully takes advantage of SLNC through a coordinated local push mechanism. Streaming contents are actively disseminated from dedicated sources to interested vehicles via local coordination of distributively selected relays, each of which will ensure smooth playback for vehicles nearby. CodePlay is designed to simultaneously improve the performance of LMS service in terms of streaming rate, service delivery delay and bandwidth efficiency. We use extensive simulations to show that CodePlay is potentially suitable for future LMS applications in VANET.