Mobile Ad hoc Networking: Imperatives and Challenges

Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANET\u27s characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future

A Hypothesis for Ad-Hoc Routing Algorithm Improvement

In this article, a new approach to reducing the complexity of routing algorithms is discussed to improve routing in ad hoc networks. To avoid duplicating the routing process for each data transfer, nodes create binary matrices for each base station and update them when the routing is complete. Routing may be made much simpler using the method given here

A Comparison of Routing Strategies for Vehicular Ad Hoc Networks

On this paper we investigate the use of ad-hoc routing algorithms for the exchange of data between vehicles. There are two main aspects that are of interest in this context: the specific characteristics of ad-hoc networks formed by vehicles and the applicability of existing ad-hoc routing schemes to networks that display these characteristics. In order to address both aspects we generate realistic vehicular movement patterns of highway traffic scenarios using a well validated traffic simulation tool. Based on these patterns we show that the characteristics of vehicular ad-hoc networks are quite different from the frequently used random waypoint model. We then proceed to evaluate the performance of a reactive ad-hoc routing protocol (DSR) and of a position-based approach (greedy forwarding as done in GPSR) in combination with a simple reactive location service. Our analysis suggests that for vehicular networks where communication spans more than 2 or 3 hops position-! based ad-hoc routing has significant advantages over reactive non-position-based approaches both in the number of successfully delivered packets and in routing overhead

Pervasive Data Access in Wireless and Mobile Computing Environments

The rapid advance of wireless and portable computing technology has brought a lot of research interests and momentum to the area of mobile computing. One of the research focus is on pervasive data access. with wireless connections, users can access information at any place at any time. However, various constraints such as limited client capability, limited bandwidth, weak connectivity, and client mobility impose many challenging technical issues. In the past years, tremendous research efforts have been put forth to address the issues related to pervasive data access. A number of interesting research results were reported in the literature. This survey paper reviews important works in two important dimensions of pervasive data access: data broadcast and client caching. In addition, data access techniques aiming at various application requirements (such as time, location, semantics and reliability) are covered

A Scalable Routing Method for Irregular Mobile Ad Hoc Networks

We designed the terminode routing protoc ol with the objective to scale in large mobile ad hoc networks where the topology, or node distribution, is irregular. Our routing protocol is a combination of two protocols: Terminode Local Routing (TLR - to reach a close destination) and Terminode Remot e Routing (TRR - to send data to remote destinations). TRR is the key element to achieve scalability and reduce dependence on intermediate systems. Termin-ode routing uses anchored paths, a list of geographic points - that are not affected by nodes mobili ty -, rather than conventional paths of nodes. Terminode routing is completed by a low-overhead distributed method for discovering of anchored paths, and by a method for handling the inaccuracy of the location information. The presented simu-lation result s confirm that terminode routing performs well in different sized networks. In smaller ad hoc networks performance of terminode routing is comparable to MANET routing protocols. In larger networks, where MANET-like routing protocols break, terminode routing performs well; moreover, in larger networks that are not uniformly populated with nodes, terminode routing outperforms the existing location-based routing protocols

Self Organized Terminode Routing - Version 2

We consider the problem of routing in a wide area mobile ad hoc network called Terminode Network. Routing in this network is designed with the following objectives. First, it should scale well in terms of the number of nodes and geographical coverage; second, routing should have scalable mechanisms that cope with the dynamicity in the network due to mobility; and third, nodes need to be highly collaborative and redundant, but, most of all, cannot use complex algorithms or protocols. Our routing scheme is a combination of two protocols called Terminode Local Routing (TLR) and Terminode Remote Routing (TRR). TLR is used to route packets to close destinations. TRR is used to route to remote destinations and is composed of the following elements: Geodesic Packet Forwarding (GPF), Anchored Geodesic Packet Forwarding (AGPF), Friend Assisted Path Discovery (FAPD), multipath routing and path maintenance. The combination of TLR and TRR has the following features: (1) it is highly scalable because every node relies only on itself and a small number of other nodes for packet forwarding; (2) it acts and reacts well to the dynamicity of the network because as a rule multipath routing is considered; and (3) it can be implemented and run in very simple devices because the algorithms and protocols are very simple and based on high collaboration. We performed simulations of the TLR and TRR protocols using the GloMoSim simulator. The simulation results for a large, highly mobile ad-hoc environment demonstrate benefits of the combination of TLR and TRR over an existing protocol that uses geographical information for packet forwarding