PSO assisted OLSR Routing for Cognitive Radio Vehicular Sensor Networks

Abstract

The recent advances in Wireless Sensor Network (WSN) has paved the way for Vehicular Sensor Network (VSN) for the effective functioning of urban environment monitoring and enabling sharing of sensitive sensor information among vehicles for safety assistance and other commercial applications. The delivery of relevant sensor information in these applications is time constrained and requires efficient data dissemination techniques to route the packet to appropriate destinations. VSNs frequently suffer from topology modifications due to the high mobile nature of vehicles. The existing reactive routing protocols in vehicular networks that work on-demand fails due to its functional limitations and existing table-driven routing protocols such as OLSR that work proactively to reduce the frequency of rerouting are unable to match the huge requirements of high mobile vehicular applications. Generally data transmissions in sensor networks experience frequent fluctuations in its operating licensed spectrum and obtain multiple channels for transmission of high bandwidth data. The overutilization of the spectrum band results in scarcity of the accessible spectrum resources. Current experiments with OLSR do not consider channel conditions and channel utilization during route calculation. One possible solution to this routing problem is to exploit the spectrum hole, which is the frequency bands not in use and opportunistically utilize them by providing Cognitive Radio (CR) assistance to OLSR for deciding the optimal path. This paper presents a PSO assisted optimal OLSR routing for efficient data communication using Cognitive Radio enabled Vehicular Sensor Networks (CR-VSNs), which takes into account of the user mobility and PU interference during the calculation of link duration among the forwarders. The proposed model was tested under simulated traffic of Chennai urban road map. Delay is observed to be minimal for data communications in CR-VSN.