A Hybrid Link Connectivity Model for Opportunistic Routing in IoV Networks under Viaduct Scenarios.

Viaduct structures have been built to ease traffic congestion in large-sized cities, especially in many large-medium cities in China. In Internet of Vehicles (IoV) networks, inter-level links in urban viaduct scenarios are established between two vehicles on different levels with various heights. The bridge surface of the viaduct acts as an obstacle in the propagation paths of inter-level links and may cause a degradation of the link quality. However, inter-level links may bring more communication opportunities when the traffic is sparse or no intra-level link can be found. Compared with traditional three-dimensional wireless networks, inter-level links for viaduct shadowing scenarios reveal unique characteristics which are not addressed by previous studies. This paper aims to estimate the unique link connectivity characteristics and figure out whether inter-level links can enhance opportunistic routing performance. To this end, we first build an accurate hybrid link availability and reliability model by considering the unique structure of viaducts. Second, we design a new metric over opportunistic routing combined with our link model. Simulation results show that taking advantage of inter-level links can improve the performance of opportunistic routing.