Georgios Y. Lazarou

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The low-energy characteristics of wireless sensor networks (WSNs) pose a great design challenge for MAC protocol design. Recent studies have proposed different cluster-based MAC protocols. In this paper, we propose an intra-cluster communication bit-map-assisted (BMA) MAC protocol for large-scale cluster-based WSNs. BMA is intended for event-driven(More)
— In this paper, we propose a new model for the slow-start phase based on the discrete evolutions on the congestion window, and we use this slow-start model together with our improved TCP steady-state model to develop an extensive stochastic model which can more accurately predict the throughput and latency of short-lived TCP connections as functions of(More)
In developing an architecture for wireless sensor networks (WSNs) that is extensible to hundreds of thousands of heterogeneous nodes, fundamental advances in energy efficient communication protocols must occur. In this paper, we first propose an energy-efficient and robust intra-cluster communication bit-map assisted (BMA) MAC protocol for large-scale(More)
— This paper addresses end-to-end connectivity planning and call admission control for a high capacity multi-beam satellite network with on-board cross-connectivity. On-board satellite switching is a technology designed to offer multi-media services, especially in demographically dispersed areas. Nevertheless, full on-board switching techniques are far from(More)
— In this letter we provide a solution to an open problem in network traffic characterization. Specifically we present a closed-form expression of the variance-time curve for a packet stream generated by exponentially distributed ON/OFF sources. So far, the variance-time curve for such processes was obtained by numerical analysis at the desired time scales.(More)
In this paper, we propose a novel and mathematically rigorous measure of variability, called the index of variability (H v ()), that fully and accurately captures the degree of variability of a typical network traffic process at each time scale and is analytically tractable for many popular traffic models. Using this proposed measure, we then analyzed two(More)
Commonly used measures of traffic burstiness do not capture the fluctuation of traffic variability over the entire range of time-scales. In this paper, we present a measure of variability, called the Index of Variability (<i>H<inf>v</inf></i>(&#964;)), that depicts the degree of variability (burstiness) of a typical network traffic process at each(More)
A cornerstone of next generation intelligent transportation systems (ITS) is a seamless integration of in-vehicle networking with existing wireless telephony infrastructure. Remote access to on-board diagnostics and performance data is a crucial requirement for ITS. In this paper, we present an extensible vehicle performance monitoring system that exploits(More)