3D geographical routing protocols in wireless ad hoc and sensor networks: an overview

Geographical routing is a prominent area of research in wireless networks where route establishment is based on known locations of wireless nodes. The location may be an exact physical location or virtual location. Many geographical routing protocols based on greedy and face routing approach have been designed for 2D networks, but these protocols may not be suitable in 3D environment like hill area, airborne networks, underground networks, underwater networks and so forth. The objective of this paper is to provide the research issues and challenges of geographical routing in the three-dimensional surface. These routing techniques suffer from many problems like energy efficiency, localization, mobility, load balancing, routing stretch, void node problems, etc. These issues have been addressed in the literature survey. In this paper, the recent research papers related to geographical routing have been discussed, but the main focus is on 3D geographic routing techniques, issues and challenges.