Lawrence Osborne

Intrusion detection techniques in mobile ad hoc and wireless sensor networks

Mobile ad hoc networks and wireless sensor networks have promised a wide variety of applications. However, they are often deployed in potentially adverse or even hostile environments. Therefore, they cannot be readily deployed without first addressing security challenges. Intrusion detection systems provide a necessary layer of in-depth protection for wired networks. However, relatively little research has been performed about intrusion detection in the areas of mobile ad hoc networks and wireless sensor networks. In this article, first we briefly introduce mobile ad hoc networks and wireless sensor networks and their security concerns. Then, we focus on their intrusion detection capabilities. Specifically, we present the challenge of constructing intrusion detection systems for mobile ad hoc networks and wireless sensor networks, survey the existing intrusion detection techniques, and indicate important future research directions.

A performance comparison of Mobile IPv6, hierarchical Mobile IPv6, and Mobile IPv6 regional registrations

IETF proposed mobile IPv6 to address the IP mobility problem in the next generation Internet protocol (IPv6) by which mobile nodes are reachable while roaming in the Internet. Nevertheless, mobile IPv6 is optimized for macro-level mobility. Hence, several micro-mobility (local-area) protocols were proposed for fast moving mobile nodes. We conducted a performance evaluation of mobile IPv6 and its proposed micro-mobility solutions, namely. Hierarchical mobile IPv6 (HMIPv6) and mobile IPv6 regional registrations (RRMIPv6). Our simulations showed that within the local domain, the performance of HMIPv6 and RRMIPv6 are much better than that of MIPv6, that the performances of HMIPv6 and RRMIPv6 are similar (e.g., for packet loss per handoff), and Mobile IPv6 slightly outperforms HMIPv6 and RRMIPv6 at higher mobile node movement rates for TCP bandwidth measurements.

Hot spot aware energy efficient clustering approach for Wireless Sensor Networks

Energy efficiency is a major design goal for resource-constraint Wireless Sensor Networks (WSNs). In this paper, an energy efficient clustering approach is employed to meet this design goal. Moreover, given the fact that most of the existing clustering algorithms do not address the hot spot problem that arises in the vicinity of the base station, an unequal clustering mechanism is implemented among nodes at different distances from the base station. In this way, the hot spot problem is mitigated by evenly distributing energy consumption in WSNs. We further use simulation to carry out performance evaluation and present analysis.

Optimal Scheduling of Urgent Preemptive Tasks

Tasks’ scheduling has always been a central problem in the embedded real-time systems community. As in general the scheduling problem is NP-hard, researchers have been looking for efficient heuristics to solve the scheduling problem in polynomial time. One of the most important scheduling strategies is the Earliest Deadline First (EDF). It is known that EDF is optimal for uniprocessor platforms for many cases, such as: non-preemptive synchronous tasks(i.e., all tasks have the same starting time and cannot be interrupted), and preemptive asynchronous tasks (i.e., the tasks may be interrupted and may have arbitrary starting time). However, Mok showed that EDF is not optimal in multiprocessor platforms. In fact, for the multiprocessor platforms, the scheduling problem is NP-complete in most of the cases where the corresponding scheduling problem can be solved by a polynomial-time algorithm for uniprocessor platforms. Coffman and Graham identified a class of tasks for which the scheduling problem can be solved by a polynomial time algorithm, that is, two-processor platform, no resources, arbitrary partial order relations, and every task is nonpreemptive and has a unit computation time. Our paper introduces a new non-trivial and practical subclass of tasks, called urgent tasks. Briefly, a task is urgent if it is executed right after it is ready or it can only wait one unit time after it is ready. Practical examples of embedded real time systems dealing with urgent tasks are all modern building alarm systems, as these include urgent tasks such as ‘checkingfor intruders’, ‘sending a warning signal to the security office’,‘informing the building’s owner about a potential intrusion’, and so on. By using propositional logic, we prove a new result in schedulability theory, namely that the scheduling problem for asynchronous and preemptive urgent tasks can be solved in polynomial time.

An integrated solution for managing replicated data in distributed systems

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A Highly Adaptable Information Dissemination Strategy

Wireless Sensor Networks have many real world applications. Accordingly, researchers and entrepreneurs are looking for a reliable, real time, and energy-efficient network structures. Traditional techniques of flooding the network with information have proved inept in all of the latter criteria. Others have made specific assumptions of how the network is used and thus make intelligent choices on data dissemination. This paper proposes a non-data centric and thus highly adaptable information dissemination protocol called the Irrigation Algorithm to efficiently route packet to base stations. To evaluate its performance this algorithm is compared with the Low-Energy Adaptive Clustering Hierarchy (LEACH) protocol.

Teaching C with UNIX for college credit to professional programmers

This paper addresses the problem of introducing the UNIX operating system and the C language to professional programmers and system analyists who have had little or no experience with either UNIX or C. Workshops given to industrial employees ordinarily last for no more than a few consecutive days and offer no college credit. In contrast, the course described in this paper required approximately nine days, spread over a three week period, and the students earned three hours of undergraduate credit towards a degree in computer science. A detailed breakdown of the contents of the lectures is given, and examples of the programming exercises done in the laboratory component of the course are presented. Observations on the effectiveness of the approach and suggestions for future improvements in the course are offered in the final section of the paper.