Reliability and Connectivity Analysis of Vehicular Ad Hoc Networks Under Various Protocols Using a Simple Heuristic Approach

Vehicular ad hoc networks (VANETs) provide alternative technology solutions to various transportation problems, and they provide a communication solution in intelligent transportation systems. However, the reliability and connectivity of VANET networks are subjects of concern. In building any routing protocol, a minimum level of network reliability must be ensured, which requires conducting a reliability analysis in order to investigate the different factors that affect reliability. Conducting a real-world reliability analysis is very expensive, and it requires significant preparation. Simulations are computationally costly due to the high number of available paths between the source node and the destination. In this article, a simplified approach is conducted that is mainly based on a simulation model of a road-type environment for a VANET network. A heuristic approach is developed for calculating the reliability based on the highest probability paths using the Dijkstra algorithm and the inclusion-exclusion approach for calculating the reliability of a given path. For vehicle-to-vehicle (V2V) communication, short-range protocols were considered-ZigBee (802.15.4), WiFi (IEEE 802.11), and Bluetooth (802.15.1)-as well as their standards for data rates, association time, and transmission range. On the other hand, the IEEE 802.11b was used for vehicle-to-roadside (V2R) communications. Another parameter that was considered was the speed limit of the road environment, and three types of road environments were evaluated: highway, urban, and mixed. Other factors that were considered were the number of vehicles, the number of roadside units, and the type of message that was transmitted. The effects of all of these elements on the connectivity of the network were studied.