Nityananda Sarma

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Flexgrid technology is now considered to be a promising solution for future high-speed network design. In this context, we need a tutorial that covers the key aspects of elastic optical networks. This tutorial paper starts with a brief introduction of the elastic optical network and its unique characteristics. The paper then moves to the architecture of the(More)
Wireless sensor networks (WSNs) are required to provide different levels of Quality of Services (QoS) based on the type of applications. Providing QoS support in wireless sensor networks is an emerging area of research. Due to resource constraints like processing power, memory, bandwidth and power sources in sensor networks, QoS support in WSNs is a(More)
One of the challenging issues in optical networks is call blocking and it increases with the number of connection requests due to the limited number of wavelength channels in each fiber link. In this paper, we propose a priority based routing and wavelength assignment scheme with incorporation of a traffic grooming mechanism (PRWATG) to reduce call(More)
Dispersion in optical fiber degrades the quality of signal in optical networks. Although the use of dispersion compensating fiber (DCF) reduces the effects of dispersion, it is expensive and has more propagation loss compared to step-index fiber (SIF). In this paper, we propose a priority based dispersion-reduced wavelength assignment (PDRWA) scheme to(More)
In this paper, we investigate the available energy-efficient Medium Access Control protocols for wireless sensor networks emphasizing on their energy saving methods and present a simple but effective energy efficient MAC protocol named AEEMAC (Adaptive Energy Efficient MAC protocol). Like SMAC, AEEMAC also employs a duty cycling to save energy by avoiding(More)
This paper studies the issues of channel allocation subject to QoS constraint(s) and fairness issues in mobile ad hoc networks (MANETs). While a solution to the hidden-terminal problem is paramount, a QoS- aware Medium Access Control (MAC) protocol must also provide a channel access mechanism that considers the QoS constraints of real-time flows. We propose(More)
In this paper, we provide higher channel access priority to frames belonging to real-time traffic with smaller contention windows as compared to frames belonging to besteffort traffic. Further, to reduce channel access delay in multihop environment, we give higher access priorities to relayed frames, within a QoS class, as compared to the generated frames(More)
In this paper, we present an efficient fault-tolerant token-based algorithm for achieving mutual exclusion (ME) in distributed systems. Nishio et al's fault-tolerant mutual exclusion algorithm requires feedbacks from every other site to recover from token loss. This results in considerable amount of waiting time and false token loss detection. Though(More)