Mobile Ad-Hoc and DTN Networks at IPCAS Lab

Intermittently-Connected Mobile Ad-hoc Networks (ICMANET) are one of the new areas in the field of wireless communication. Networks under this class are potentially deployed in challenged environments using isolated mobile devices with limited resources. They are emerging as a promising technology in applications such as in wildlife management, military surveillance, underwater networks, and vehicular networks. A ICMANET, also known as the Delay Tolerant Network (DTN), is typically different from traditional mobile ad-hoc networks (MANETs) in the sense that in the latter, communication between two nodes is possible at any time via a path of intermediate nodes although this path may vary with time. However, in an ICMANET, paths between two nodes are intermittent and communication between two nodes have to be established only by multihop paths that span over space and time. In other words, there is no end-to-end path between the two at any given instant. Enabling communications in such an intermittently connected network requires a departure from the traditional end-to-end communication model. Opportunistic networking is potentially an enabling technique for node-to-node communication between users that might never be connected through a complete path at a given time. Our work in this research is focused on obtaining fundamental limits, efficient algorithms and secure/reliable protocols for these networks.

 

Constraint Networks Wireless Sensor Networks: 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.

 

Intermittently-Connected Mobile Ad-hoc Networks

 

Intermittently-Connected Mobile Ad-hoc Networks (ICMANET) are one of the new areas in the field of wireless communication. Networks under this class are potentially deployed in challenged environments using isolated mobile devices with limited resources. They are emerging as a promising technology in applications such as in wildlife management, military surveillance, underwater networks, and vehicular networks. Recent focus on these networks has naturally generated efforts to analytically understand them. In contrast to conventional Mobile Ad-hoc Networks (MANETs), links on an end-to-end path in ICMANETs do not exist contemporaneously. This compounds the analysis of such networks. Our research provides one of the first steps for performance modeling of ICMANETs. This is very crucial in the design of practical schemes targeted to offer good performance across different mobility scenarios. Most current analytical research employs simple mobility models such as the Poisson-contact model, which are unrealistic. Departing heavily from this trend, the investigator has developed performance analysis under the very general class of stationary mobility models. This paves the way to analytically understand the effect of mobility parameters on performance. In particular, the research answers questions of the following nature: What parameters of the mobility model affect ICMANETs performance? How does one extract the necessary information? The research objective is to develop novel approaches in performance modeling of ICMANETs, drawing out key ideas from Markov-chain- and queuing- theory. The research attempts to arrive at a novel framework which is capable of capturing key network characteristics under practical constraints such as finite bandwidth, random contact durations, and finite node buffers. Key performance measures such as throughput are explored for various communication scenarios, routing protocols, network coding and buffer management schemes.