Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Engineering

Optimal Fixed And Scalable Energy Management For Wireless Networks, Rahul Mangharam, Sofie Pollin, Bruno Bougard, Ragunathan Rajkumar, Francky Catthoor, Liesbet Van Der Perre, Ingrid Moerman Oct 2012

Optimal Fixed And Scalable Energy Management For Wireless Networks, Rahul Mangharam, Sofie Pollin, Bruno Bougard, Ragunathan Rajkumar, Francky Catthoor, Liesbet Van Der Perre, Ingrid Moerman

Rahul Mangharam

In many devices, wireless network interfaces consume upwards of 30% of scarce portable system energy. Extending the system lifetime by minimizing communication power consumption has therefore become a priority. Conventional energy management techniques focus independently on minimizing the fixed energy consumption of the transceiver circuit or on scalable transmission control. Fixed energy consumption is reduced by maximizing the transceiver shutdown interval. In contrast, variable transmission rate, coding and power can be leveraged to minimize energy costs. These two energy management approaches present a tradeoff in minimizing the overall system energy. For example, variable energy costs are minimized by transmitting at …


Rt-Link: A Time-Synchronized Link Protocol For Energy-Constrained Multi-Hop Wireless Networks, Rahul Mangharam, Anthoney Rowe, Raj Rajkumar Oct 2012

Rt-Link: A Time-Synchronized Link Protocol For Energy-Constrained Multi-Hop Wireless Networks, Rahul Mangharam, Anthoney Rowe, Raj Rajkumar

Rahul Mangharam

We propose RT-Link, a time-synchronized link protocol for real-time wireless communication in industrial control, surveillance and inventory tracking. RT-Link provides predictable lifetime for battery-operated embedded nodes, bounded end-to-end delay across multiple hops, and collision-free operation. We investigate the use of hardwarebased time-synchronization for infrastructure nodes by using an AM carrier-current radio for indoors and atomic clock receivers for outdoors. Mobile nodes are synchronized via in-band software synchronization within the same framework. We identify three key observations in the design and deployment of RT-Link: (a) Hardware-based global-time synchronization is a robust and scalable option to in-band softwarebased techniques. (b) Achieving global …


Green Scheduling For Radiant Systems In Buildings, Truong Nghiem, Madhur Behl, George Pappas, Rahul Mangharam Oct 2012

Green Scheduling For Radiant Systems In Buildings, Truong Nghiem, Madhur Behl, George Pappas, Rahul Mangharam

Rahul Mangharam

In this report we look at the problem of peak power reduction for buildings with electric radiant floor heating systems. Uncoordinated operation of a multi-zone radiant floor heating system can result in temporally correlated electricity demand surges or peaks in the building’s electricity consumption. As peak power prices are 200-400 times that of the nominal rate, this uncoordinated activity can result in high electricity costs and expensive system operation. We have previously presented green scheduling as an approach for reducing the aggregate peak power consumption in buildings while ensuring that indoor thermal comfort is always maintained. This report extends the …


The Wireless Control Network: Monitoring For Malicious Behavior, Shreyas Sundaram, Miroslav Pajic, Christoforos Hadjicostis, Rahul Mangharam, George Pappas Oct 2012

The Wireless Control Network: Monitoring For Malicious Behavior, Shreyas Sundaram, Miroslav Pajic, Christoforos Hadjicostis, Rahul Mangharam, George Pappas

Rahul Mangharam

We consider the problem of stabilizing a plant with a network of resource constrained wireless nodes. In a companion paper, we developed a protocol where each node repeatedly transmits a linear combination of the values in its neighborhood. For certain topologies, we showed that these linear combinations can be designed so that the closed loop system is stable (i.e., the wireless network itself acts as a controller for the plant). In this paper, we design a Intrusion Detection System (IDS) for this control scheme, which observes the transmissions of certain nodes in the network and uses that information to (a) …