Routing protocol in a hybrid sensor and vehicular network for different mobility scenario

Vehicular ad hoc network (VANET) is a subset of mobile ad hoc network (MANET) which it was proposed in the last few years to improve the road safety. Many proposed designs were integrated into the modern innovation wireless sensor network (WSN) with the VANET. So, this combination overcomes the VANET's breakdown which it is the inability to identify the hazardous conditions on the road on time and maintain the communication connectivity in the low-density area such as rural areas. It is called Hybrid Sensor and Vehicular Network (HSVN) in which the sensor nodes are distributed along with the roadsides and have a centralized communication channel with data collector called sensor gateway. The gateway has a responsibility to accumulate the data from the distributed nodes and forward them to the moving vehicles cautioning them from dangerous conditions, whatever the density amount of the road or the connectivity of the vehicular nodes. This dynamic topology force new demands and challenges that should be solved regarding suitable routing protocols that should be applied to transfer the data among the nodes with high performance regarding throughput, packet delivery ratio, and latency. In this paper, the performance of Ad hoc On-Demand Distance Vector (AODV) and Optimized Link State Routing (OLSR) routing protocols is investigated using the discrete event network simulator (NS-3). The Simulation results revealed that OLSR has outperformed AODV routing protocol in term of network metrics with a neglected end-end delay. That's mean, it has superior performance when sending critical data from WSN gateway to the specific convoyed vehicle. Moreover, OLSR has better performance regarding the average throughput by 17.4% and 10.9% for both low-density and high-density scenarios, respectively when the payload was 1000 bytes.