Mahasweta Sarkar

A Novel Scheme for an Energy Efficient Internet of Things Based on Wireless Sensor Networks.

One of the emerging networking standards that gap between the physical world and the cyber one is the Internet of Things. In the Internet of Things, smart objects communicate with each other, data are gathered and certain requests of users are satisfied by different queried data. The development of energy efficient schemes for the IoT is a challenging issue as the IoT becomes more complex due to its large scale the current techniques of wireless sensor networks cannot be applied directly to the IoT. To achieve the green networked IoT, this paper addresses energy efficiency issues by proposing a novel deployment scheme. This scheme, introduces: (1) a hierarchical network design; (2) a model for the energy efficient IoT; (3) a minimum energy consumption transmission algorithm to implement the optimal model. The simulation results show that the new scheme is more energy efficient and flexible than traditional WSN schemes and consequently it can be implemented for efficient communication in the IoT.

Cell Zooming for Power Efficient Base Station Operation

With enormous growth in the telecommunication industry, energy efficiency has become a critical issue. Base stations and the core network account for a large amount of energy consumption today. Traditional energy saving techniques switch some base stations off completely during light loads to save energy. This creates problems for the backhaul network and also for quickly returning to full capacity when demand increases. In this paper, we propose novel cell zooming techniques to reduce energy consumption at base stations. With cell zooming, base stations dynamically adjust their coverage radius and hence their transmit powers based on user locations. The transmit power is set to the minimum required level depending on user locations, signal to interference and noise ratio (SINR) and quality of service (QoS) requirements of the users. Base stations are never completely switched off. Our simulations show that the proposed cell zooming algorithm reduces the energy consumption of base stations by up to 40% compared to traditional static-coverage-area base stations without compromising on the QoS requirements of any user in the cell.

BEST-MAC: Bitmap-Assisted Efficient and Scalable TDMA-Based WSN MAC Protocol for Smart Cities

Smart cities have been envisioned during the last decade. Moreover, various projects have been initiated to bring this concept into reality. Smart city is basically an emergence of the existing and new Information and Communications Technologies (ICT) to make our living standard more safe and digitized. Wireless communications, such as sensors, actuators, intelligent transportation systems, and smart grids, have played a vital role in the dissemination of information under the given circumstances. Similarly, it is hard to declare any city as a smart city without taking benefits from wireless sensor networks (WSNs). However, with new requirements and delay sensitive applications, the existing WSN requires significant alterations at several layers. In this paper, a new time division multiple access (TDMA)-based medium access control (MAC) protocol, called bitmap-assisted efficient and scalable TDMA-based MAC (BEST-MAC), is proposed for adaptive traffic in hierarchical WSNs that can be deployed in the smart cities. BEST-MAC is specifically designed to improve the quality control of such smart cities applications, where diverse traffic is required and loss or delay in data traffic is unacceptable. The main contributions of BEST-MAC include: 1) it uses small size time slots; 2) the number of those time slots is more than the number of member nodes; 3) knapsack algorithm is used to schedule time slots; and 4) short node address (1 B) is proposed to identify the member nodes. First two contributions of BEST-MAC handle adaptive traffic loads of all members in an efficient manner. The knapsack algorithm not only reduces the job completion time of a node but also minimizes the average packet delay with better link utilization. The short node address reduces the control overhead that improves the energy efficiency. The simulation results verify that the proposed BEST-MAC transmits more data with less delay and energy consumption compared with the existing MAC protocols.

QoS-aware dynamic cell reconfiguration for energy conservation in cellular networks

Given the significant energy consumption in operating base stations (BSs), improving their energy efficiency is an important problem in cellular networks. To this end, this paper proposes a novel framework, called DCR (dynamic cell reconfiguration) that dynamically adjust the set of active BSs and user association according to user traffic demand for energy conservation. In order to overcome prohibitive computational complexity in finding an optimal solution, we take an approach to design simple yet effective algorithms. We demonstrate that the proposed framework is not only computationally efficient but also can achieve the performance close to the optimum solution from an exhaustive search. Through simulations based on a real dataset of BS topology and utilization, we show that DCR can yield about a 30-40% reduction compared to the conventional static scheme where all BSs are always turned on.

Channel modelling based on statistical analysis for brain-computer-interface (BCI) applications.

This poster showcases the experimental set up and the transmission characteristics of an ECog signal emitted by an implanted UWB transmitter in the human brain. We study the signal characteristics as it traverses medium like tissue fluid and blood to reach a UWB receiver, placed externally on the head.

Smart Connectivity for Internet of Things (IoT) Applications

The IoT scenario is characterized with ultra-dense interworking of billions and billions of devices through a myriad of technologies for the delivery of smart personalized services and applications. The main challenges and distinctive features of this scenario are the large amount of information gathered from the ambient environment and the human body that must be processed mostly in real- or near-real time for the unobtrusive delivery of personalized and often of critical to the user’s well-being services. Smart connectivity in an AAL context relates to the availability of a reliable data channel between devices and between the human and devices and enabling an interface to the cloud/network where information gets personalized. This chapter examines the main research challenges related to the enabling of smart connectivity in an AAL context and proposes a novel approach to scalable and autonomous interactions for an enhanced personalized experience.

A smart transmission scheme for emergency data from a network of bio-sensors on the human body

As a nation of an estimated 45 million uninsured and underinsured Americans (almost 15% of the population), out of which over 11 million suffer from chronic diseases who require constant medical supervision, America today is plagued by the national crisis of inadequate and expensive healthcare. This paper introduces an architecture of a multi-tier telemedicine system comprised of strategically placed bio-sensors on a human body capable of collecting vital medical statistics (such as heart rate and blood pressure) and transmitting them (wired or wirelessly)over multiple hops to a remote medical server at a caregivers location thereby taking telemedicine from the desktop to roaming. However, fundamental wireless networking issues must be addressed and resolved before this dream can be realized. In this regards, this paper proposes a Medium Access Control (MAC) protocol specifically designed for a Wireless Body Area Network (WBAN). Our protocol is designed to cater to the Quality of Service (QoS) requirements that would be essential for an application like WBAN. It fuses data from several biosensors and based on the time criticality of the data, schedules them intelligently such that the data reaches its destination in a timely and energy efficient manner. Simulation results show that the traffic prioritization and scheduling scheme proposed in our MAC architecture surpasses the standard IEEE 802.15.4 MAC protocol in performance.

On detecting CTS duration attacks using K-means clustering in WLANs

IEEE 802.11 based Wireless LAN (WLAN) standard has been one of the most successful wireless technology standards with total expected sales rising to a staggering

A MAC Layer Protocol for Sensor Networks Using Directional Antennas

6.1Billion by 2015. The proliferation of 802.11 based WLANs highlights the need to focus on development of new solutions for security as enterprises and campuses increasingly being covered by WLANs. Denial of Service (DoS) is one of the popular attacks that prevents WLAN users from accessing the wireless network resources. Most DoS attacks such as the Clear-to-Send (CTS) duration attack is easy to carry out by an attacker. This work focuses on the use of clustering techniques on wireless traffic datasets for detecting CTS-based DoS attacks on 802.11 WLANs. Performance evaluation shows that, under the cases of naïve CTS duration attacker as well as the sophisticated CTS duration attacker, the k-means clustering technique is able to achieve high detection rates and low false positive rates with relatively small values of k (i.e., number of clusters).

An Algorithm to Enhance QoS for Streaming Video over WLANs

Using directional antenna in ad hoc networks, offer many benefits in contrast to their classical omni-directional counterparts. The most important benefits are the significant improvement in spatial reuse, reduction of the radio interference, increase in coverage range and subsequently an increase in network capacity on the whole. On the other hand, directional transmission increases the hidden terminal problem and the problem of deafness. To best utilize directional antennas, a suitable Medium Access Control (MAC) protocol must be designed. Current MAC protocols, such as the IEEE 802.11 standard for Wireless LANs, assume the omni-directional antenna at its Physical layer and thus does not fully exploit the capabilities of a directional antenna. In this paper, we propose a MAC protocol for wireless ad hoc networks which fully exploits the potentials of directional antennas. We evaluate our work through simulation studies performed on the network simulator – NS2. Numerical results show that our protocol offers significant improvement in throughput when compared to the performance of traditional 802.11 MAC protocol and D-MAC which is a Directional MAC protocol for ad hoc networks.