Ad-Hoc and Sensor Networks at IPCAS Lab

Today, convergence of sensor technologies, communications, and computing has emerged to provide the potential to overcome the barriers of time, scale, and environment. Distributed sensor networks are becoming a feasible solution to various data collection applications such as military battlefields, scientific experimentation sites, medical instrumentation and domestic appliances. Typical sensor networks are often infrastructure-less and may include hundreds to several thousands of randomly scattered sensor nodes that are constrained in physical size, available energy, computational ability and transmission range. The full potential of sensor networks has yet to be realized as a result of design challenges in the sensor technology and related networking issues. Professor Fekri and his research group are investigating the fundamental limits and techniques for processing and distribution of information in wireless sensor networks. In particular we are interested in reliable and secure communication and distributed processing in the presence of constraints such as limited energy, lossy channels, interference, latency and throughput, and adversary attacks.

Connectivity/Coverage | Sleeping Sensors | Latency/Throughput Broadcast Protocols | Distributed Source Coding | Security

 

Connectivity and Coverage:

While wireless sensor networks are expected to be highly constrained, they need to offer reasonable quality of service. Network properties such as connectivity and average path length are very essential to maintain such quality. In a (randomly) distributed sensor network, two nodes may not be able to communicate with each other, as sensors maintain very low communication range to conserve their limited energy resources. Further, a distributed sensor network, once deployed, may be expected to perform its task without maintenance for a large period of time. This could lead to the sensor failure for reasons such as running out of power and adversary attacks. Further, two sensors may not be able to recognize each other (e.g., due to short comings of secret key distribution schemes), even though they are within communication range, making the network prone to link failures. All of these make the sensor networks "unreliable''.

Sensor networks with unreliable sensors and communication links pose several challenges to ensure network connectivity, k-connectivity, and coverage. The goal of this research is to develop analytical tools for studying these graph theoretic and geometric properties of unreliable wireless sensor networks in small and large scale regimes.