Geo-LANMAR: A scalable routing protocol for ad hoc networks with group motion

Network scalability is one of the critical challenges and requirements in routing protocols for ad hoc networks. This paper presents a novel scalable routing protocol called Geo-LANMAR. The proposed protocol inherits the group motion support of landmark routing (LANMAR) and applies the geo-routing concept to deliver packets efficiently. In this framework, the integration between geo-coordinates and table-driven IP addressing is introduced. There is also an integration of group management with geo-forwarding and IP group management. Geo-LANMAR uses link-state propagation over a virtual topology built on landmarks, and a fisheye like scheme makes this propagation very efficient. The virtual topology helps recover from voids. For extra efficiency, a novel metric called effective traveled distance (ETD) allows us to predict voids or obstacles. With respect to LANMAR, Geo-LANMAR reduces advertisement update overhead (O/H) and features robust forwarding. Consequently, Geo-LANMAR is more scalable to large ad hoc networks with group motion. The performance evaluation of Geo-LANMAR shows that Geo-LANMAR gives high scalability for large networks in terms of control O/H, end-to-end delay, and packet delivery ratio as compared with other routing protocols such as AODV, LANMAR, and GPSR. Copyright (C) 2006 John Wiley & Sons, Ltd.