Ad hoc wireless distribution service

About: Ad hoc wireless distribution service is a research topic. Over the lifetime, 17734 publications have been published within this topic receiving 488205 citations.

Providing Fault-Tolerant Ad hoc Routing Service in Adversarial Environments

Abstract: Most existing designs of ad hoc networks are based on the assumption of non-adversarial environments, where each node in the network is cooperative and well-behaved. When misbehaving nodes exist in the network, the performance of current routing protocols degrades significantly. Since ad hoc networks, consisting of autonomous nodes, are open and distributed in nature, maintaining a fault-free network environment is extremely difficult and expensive. In this paper, we propose a new routing service named best-effort fault-tolerant routing (BFTR). The design goal of BFTR is to provide packet routing service with high delivery ratio and low overhead in presence of misbehaving nodes. Instead of judging whether a path is good or bad, i.e., whether it contains any misbehaving node, BFTR evaluates the routing feasibility of a path by its end-to-end performance (e.g. packet delivery ratio and delay). By continuously observing the routing performance, BFTR dynamically routes packets via the most feasible path. BFTR provides an efficient and uniform solution for a broad range of node misbehaviors with very few security assumptions. The BFTR algorithm is evaluated through both analysis and extensive simulations. The results show that BFTR greatly improves the ad hoc routing performance in the presence of misbehaving nodes.

The Grid Roofnet: a Rooftop Ad Hoc Wireless Network

Abstract: This thesis describes the Grid Roofnet, a rooftop wireless Ad Hoc network built using off the shelf computers and 802.11 hardware along with special software. The Roofnet is a real-world testbed for wireless Ad Hoc networking research, and as a side effect also provides network access to a small number of apartments in Cambridge, MA. We describe the construction and performance of the network, and draw some conclusions about the viability of such networks and directions for future research. Thesis Supervisor: Robert T. Morris Title: Assistant Professor of Computer Science and Engineering

Secure and efficient key management in mobile ad hoc networks

Abstract: In mobile ad hoc networks, due to unreliable wireless media, host mobility and lack of infrastructure, providing secure communications is a big challenge in this unique network environment. Usually cryptography techniques are used for secure communications in wired and wireless networks. The asymmetric cryptography is widely used because of its versatileness (authentication, integrity, and confidentiality) and simplicity for key distribution. However, this approach relies on a centralized framework of public key infrastructure (PKI). The symmetric approach has computation efficiency, yet it suffers from potential attacks on key agreement or key distribution. In fact, any cryptographic means is ineffective if the key management is weak. Key management is a central aspect for security in mobile ad hoc networks. In mobile ad hoc networks, the computational load and complexity for key management is strongly subject to restriction of the node's available resources and the dynamic nature of network topology. In this paper, we propose a secure and efficient key management framework (SEKM) for mobile ad hoc networks. SEKM builds PKI by applying a secret sharing scheme and an underlying multicast server group. In SEKM, the server group creates a view of the certification authority (CA) and provides certificate update service for all nodes, including the servers themselves. A ticket scheme is introduced for efficient certificate service. In addition, an efficient server group updating scheme is proposed.

Dynamic Source Routing Protocol (DSR)

Abstract: The Dynamic Source Routing protocol (DSR) is a simple and efficient routing protocol designed specifically for use in multi-hop wireless ad hoc networks of mobile nodes. DSR allows the network to be completely self-organizing and self-configuring, without the need for any existing network infrastructure or administration. The protocol is composed of the two mechanisms of Route Discovery and Route Maintenance, which work together to allow nodes to discover and maintain source routes to arbitrary destinations in the ad hoc network. The aim of this research is to provide a solution on the basis of reputation method to solve routing issues raised by misbehaving nodes.

3hBAC (3-hop between adjacent clusterheads): a novel non-overlapping clustering algorithm for mobile ad hoc networks

Abstract: The clustering protocol of an ad hoc network is always with interest. In this paper, we present a novel non-overlapping clustering algorithm, 3-hop between adjacent clusterheads (3hBAC), which can decrease the number of clusters without loss of connection information. In the cluster maintenance phase, we combine 3hBAC with least cluster change (LCC) algorithm to further decrease the cluster change and to extend average clusterhead time and membership time. The performances of 3hBAC are compared with highest-connectivity clustering (HCC), random competition-based clustering (RCC) in terms of average number of clusters, average clusterhead time and average membership time. 3hBAC outperforms HCC and RCC in both the cluster formation and maintenance phase.