Lisa Frye

Topology Maintenance of Wireless Sensor Networks in Node Failure-prone Environments

A critical issue in wireless sensor networks is topology management, and maintaining connectivity throughout the network and having a sufficient network lifetime in particular. There have been many topology management schemes proposed. Most of them conserve energy by periodically putting nodes to sleep. One consideration often overlooked is the fact that sensor nodes fail, especially in harsh environments. In this paper, a modification to an existing topology management scheme, Naps, is proposed to ensure very minimal data loss while also handling node failures. The idea is to conserve energy to prolong the lifetime of the nodes and the sensor network while maintaining a constantly connected sensor network. Simulation results demonstrate that failed nodes do not have a significant impact on network connectivity or lifetime, at least in a random, uniform deployment. The paper also illustrates that two different approaches taken in the Naps modification for compensating for failed nodes produce similar results

An ontology-based system to identify complex network attacks

Intrusion Detection Systems are tools used to detect attacks against networks. Many of these attacks are a sequence of multiple simple attacks. These complex attacks are more difficult to identify because (a) they are difficult to predict, (b) almost anything could be an attack, and (c) there are a huge number of possibilities. The problem is that the expertise of what constitutes an attack lies in the tacit knowledge of experienced network engineers. By providing an ontological representation of what constitutes a network attack human expertise to be codified and tested. The details of this representation are explained. An implementation of the representation has been developed. Lastly, the use of the representation in an Intrusion Detection System for complex attack detection has been demonstrated using use cases.

Topology Management for Wireless Sensor Networks

Topology management is a key component of network management of wireless sensor networks. The primary goal of topology management is to conserve energy while maintaining network connectivity. Topology management consists of knowing the physical connections and logical relationships among the sensors. Another important concept of topology management is to have only a subset of nodes actively participating in the network, thus creating less communication and conserving energy in nodes. This chapter provides a detailed survey of existing topology management algorithms proposed for wireless sensor networks in three categories: topology discovery (learning the layout of the nodes), sleep cycle management (allowing some nodes to sleep to conserve energy), and clustering (grouping nodes to conserve energy).

Issues in the instantiation of template classes

Teaching students to incorporate template classes into their C++ projects is an important concept in object-oriented programming. The most efficient implementation method for template classes is dependent on several factors. Two significant factors are different integrated development environments with differing requirements, and incongruous philosophies among instructors. Herein, several template class instantiation methods under Gnu compilers will be discussed, along with their pros and cons.

Performance Analysis and Evaluation of an Ontology-Based Heterogeneous Multi-tier Network Management System

Many of today’s networks are Heterogeneous Multi-tier Networks, consisting of wired, Ad-hoc, and wireless sensor nodes. Each node type requires a management system and method to retrieve management data from the nodes. Management of the Heterogeneous Multi-tier Network can be daunting, requiring multiple management systems and manual data aggregation and analysis. A network management system to properly manage such a network was developed to automate some of the data aggregation and analysis. Ontology was utilized as the foundation of the Heterogeneous Multi-tier Network Management System to provide automation of management tasks. Analysis of the developed management system is presented to evaluate its response time and scalability. The analytical model was also utilized to perform bottleneck analysis. Results from the Network Management System deployed in a test environment supported the theoretical results.

Wireless sensor networks: learning and teaching

There have been many response deficiencies cited regarding a fire departments ability to fight a structure fire. The attacks on the World Trade Center on 9/11 highlighted many of these problems and demanded the attention of the world. Wireless Sensor Networks (WSN) can benefit fire fighters as they bravely enter a structure fire. WSNs are networks consisting of many small sensors or nodes. The sensors can monitor a variety of data, such as the environment, movement and patient health readings. There has been much research completed in the area of WSNs but most of this research is proven via simulations with little actual experimentation or deployment of devices. Wireless sensor networks is an exciting and a new area of research; it has captured the interest of many researchers. The intrigue easily attracts the attention of students as well. With the help of various students, a wireless sensor network will be deployed in a fire training center to test a deployment in a structure. The primary measurement will be the performance of the sensors and the sensor network. Several students have been utilized to assist in writing the necessary programs, and more will continue to contribute to the project. This project will maintain research in utilizing WSNs in a fire fighting scenario and will continue to employ students to get them excited about learning and research.