Estimation of Collision Probability in a Saturated Vehicular Ad-Hoc Networks

It is envisioned that WAVE standard, the technology for future DSRC communication in vehicular environments will support vehicular communication networks in order to provide safety and infotainment services as part of ITS. However, the defined parameter set for the EDCA used in 802.11p is capable of prioritizing messages, and when number of vehicles sending AC3 increases, packet collision probability will undeniably increase significantly. Since transmission collisions can only be detected after a transmission if at all, high percentage of packet collision probability will lead to many dead channel access times with no useful data exchange. We proposed CODER scheme which uses network coding to increase packet content and mitigate the problem of high collision probability which is inherent in WAVE standard by minimizing contention. Results of the theoretical analysis and simulation experiments show that CODER scheme has a performance gain over WAVE in terms of reduced collision rate.