Efficient safety message forwarding using multi-channels in low density VANETs

Vehicular Ad-hoc networks (VANETs) provide a way for a vehicle to deliver various types of information to users or drivers in other vehicles. Distributing a large amount of information such as multimedia messages in a single control channel makes the control channel easily congested. Transmitting multimedia messages through multi-channel to avoid this congestion becomes a feasible solution. However, low-connectivity in a low vehicle density in multi-channel poses unique challenges and can produce connection failure if this issue is not carefully addressed. In this paper, a network coding technique with divide-and-deliver is introduced to solve this unique challenge for delivering multimedia contents through multiple service channels in a low vehicle density. Through the rigorous analytical derivation and extensive simulation, we show the proposed scheme significantly improves reliability with minimum usage of the control channels in a typical VANETs environment.