Software Defined Networking Based On-Demand Routing Protocol in Vehicle Ad-Hoc Networks

摘要

This paper comes up with a SDN Based Vehicle Ad-Hoc On-Demand Routing Protocol (SVAO), which separates the data forward-ing layer and network control layer, as in software defined networking (SDN), to enhance data transmission efficiency within vehi-cle ad-hoc networks (VANETs). The roadside service unit plays the role of local controller and is in charge of selecting vehicles to forward packets within a road segment. All the vehicles state in the road. Correspondingly, a two-level design is used. The global level is distributed and adopts a ranked query scheme to collect vehicle information and determine the road segments along which a message should be forwarded. On the other hand, the local level is in charge of selecting forwarding vehicles in each road seg-ment determined by the global level. We implement two routing algorithms of SVAO, and compare their performance in our simu-lation. We compare SVAO with popular ad-hoc network routing protocols, including Optimized Link State Routing (OLSR), Dy-namic Source Routing (DSR), Destination Sequence Distance Vector (DSDV), and distance-based routing protocol (DB) via simula-tions. We consider the impact of vehicle density, speed on data transmission rate and average packet delay. The simulation results show that SVAO performs better than the others in large-scale networks or with high vehicle speeds.