Talk: Energy-efficient Wakeup Scheduling and Flexible Directional Flooding for Real-Time Data Delivery in WSNs, Binoy Ravindran

Dear GKmM members,
We are very pleased to announce our next invited seminar talk for the GKMM session on July 13th, 2011. The talk takes place at 15:00h in S2/02, Room A102.

Our guest speaker is Prof. Binoy Ravindran, a full Professor in the Electrical and Computer Engineering Department at Virginia Tech, Blacksburg, Virginia, USA. His expertise include real-time, embedded, and networked systems with a particular focus on resource management at various levels of abstraction.

The Title of the talk is:
"Energy-efficient Wakeup Scheduling and Flexible Directional Flooding for Real-Time Data Delivery in Wireless Sensor Networks"

Abstract:

Wireless sensor networks (WSNs) have increasingly received attention in a broad array of time-sensitive application domains, e.g., surveillance, environment monitoring, medical diagnostics, industrial control. As they are battery-powered, energy is a critical resource for WSNs. This talk will focus on two complimentary WSN problem spaces in supporting time-sensitive applications: wakeup scheduling and constrained flooding.

The major objective of wakeup scheduling is to maintain network connectivity while reducing the idle state energy consumption. The heterogeneous wakeup-scheduling problem is how to guarantee that WSN nodes with different awake/sleep-scheduling patterns (e.g., cluster heads, cluster members) can discover each other within bounded delay in the presence of clock drift. We present the Cyclic Quorum System Pair (CQS-Pair) as a solution to this problem. In CQS-Pair, a quorum system specifies the awake/sleep-scheduling pattern during n continuous beacon intervals for each node, where n constitutes the cycle length and may be different for different nodes. Using CQS-Pair, we show that WSNs achieve better trade-off between energy consumption and average delay. Our experimental studies using a prototype implementation validate CQS-Pair’s time bounds.

Building on CQS-Pair, we present a constrained flooding protocol, called CFlood that enhances the deadline satisfaction ratio per unit energy consumption of time-sensitive WSN packets. CFlood improves real-time performance by flooding, but effectively constrains energy consumption by controlling the scale of flooding, i.e., flooding only when necessary. If unicasting meets the distributed sub-deadline of a hop, CFlood aborts further flooding even after flooding has occurred in the current hop. Our simulation-based experimental studies show that CFlood achieves higher deadline satisfaction ratio per unit energy consumption than previous multipath forwarding protocols, especially in sparsely deployed or unreliable WSNs.

Speaker Bio:

Binoy Ravindran is an Associate Professor in the Electrical and Computer Engineering Department at Virginia Tech, Blacksburg, Virginia, USA. His research interests include real-time, embedded, and networked systems, with a particular focus on resource management at various levels of abstraction. He and his students have published more than 170 papers in this space, and some of his group’s results have been transitioned to US Department of Defense programs. Dr. Ravindran is an US Office of Naval Research Distinguished Faculty Fellow, an ACM Distinguished Speaker, and an Associate Editor of ACM Transactions on Embedded Computing Systems.