Environment aware location service for mobile ad hoc networks

Abstract

For a successful and efficient communication in mobile ad hoc network, routing protocols play a vital role. Among those proposed in literature, location based routing protocols show their superiority over others by exhibiting low communication overhead, higher scalability and better adaptability in scenarios where node mobility is high; especially high scalability makes them attractive for large-scale deployment of ad hoc network. As the name indicates, location based routing protocols greatly rely on the precise knowledge of the mobile devices' location, which is provided by a location service. Huge research efforts have been dedicated in developing location services where the researchers have emphasized on making the services scalable but little consideration was given on their applicability in real-world environment as most services have been designed assuming an ideal deployment environment that fails to represent the impact of the real-world on node mobility and signal propagation. A location service most suitable in a realistic environment must consider the impact of environmental contexts (obstacles, pathways, etc.), making the mobility model a vital factor through which the environmental impact is reflected in simulation. This study develops a novel mobility model which emulates realistic node mobility more accurately by considering various environmental contexts. Non-uniform node distribution caused by environmental contexts impacts the performance of the existing location services drastically. This demands a pressing need for a location service that can adopt itself while ensuring seamless service. In this study non-uniform node distribution arising from natural phenomena is considered while designing a novel location service protocol that adapts itself to the presence and nature of the environmental context. As the location service utilizes the underlying location based routing protocol for transferring service related messages, signal attenuation experienced due to environmental contexts is also taken into account in the routing protocol for finding routable paths, which in turn further enhances the performance of the proposed location service significantly. The proposed location service shows a superior ability to provide location information while maintaining scalability. A detailed mathematical model of the scalability is also presented. Exhaustive simulation has been conducted using a real-world map, which demonstrates the significant superiority of the proposed scheme over other competitive location service protocols (e.g., HLS (Hierarchical Location Service) and GLS (Grid Location Service)) for both uniformly and non-uniformly distributed nodes, and establishes its greater applicability to real-world environments.