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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.

Simulation environments are an important tool for the evaluation of new concepts in networking. The study of mobile ad hoc networks depends on understanding protocols from simulations, before these protocols are implemented in a real-world setting. To produce a real-world environment within which an ad hoc network can be formed among a set of nodes, there is a need for the development of realistic, generic and comprehensive mobility, and signal propagation models. In this paper, we propose the design of a mobility and signal propagation model that can be used in simulations to produce realistic network scenarios. Our model allows the placement of obstacles that restrict movement and signal propagation. Movement paths are constructed as Voronoi tessellations with the corner points of these obstacles as Voronoi sites. Our mobility model also introduces a signal propagation model that emulates properties of fading in the presence of obstacles. As a result, we have developed a complete environment in which network protocols can be studied on the basis of numerous performance metrics. Through simulation, we show that the proposed mobility model has a significant impact on network performance, especially when compared with other mobility models. In addition, we also observe that the performance of ad hoc network protocols is effected when different mobility scenarios are utilized.

Actuation ability introduces a fundamentally new design dimension in wireless ad-hoc sensor networks, allowing the network to adaptively reconfigure and repair itself in response to unpredictable run-time dynamics. One of the key network resources in these systems is energy and several uncontrollable factors lead to situations where a certain segment of the network becomes energy constrained before the remaining network. The performance gets limited due to the constrained sections. We argue that in this scenario, instead of rendering the complete network useless, the remaining energy resources should be reorganized to form a new functional topology in the network. We present methods for the network to be aware of its own integrity and use actuation to improve performance when needed. This capability of the system is referred to as “self aware actuation”.In this paper, we consider a network where nodes (or a subset of the nodes) have traction ability. The network uses mobility to repair the coverage loss in the area being monitored by it. We present a completely distributed energy aware algorithm (referred to as Co-Fi) for coordinated coverage fidelity maintenance in sensor networks. The energy overheads of mobility are incorporated in the algorithm, thus leaving no hidden costs. Our preliminary analysis shows that Co-Fi can significantly help improve the usable lifetime of these networks.