RideSharing: Fault Tolerant Aggregation in Sensor Networks Using Corrective Actions

sameh gobriel, University Of Pittsburgh, CS Department

Tuesday, September 12, 2006, Noon
Noon - SENSQ 5317
Free pizza for attendees starting at 11:45 a.m.

Hosted by Rami Melhem and Daniel Mosse'

Abstract

In Wireless Sensor Networks (WSNs), the users' objective is to extract useful global information by collecting individual sensor readings. Conventionally, this is done using in-network aggregation on a spanning tree from sensors to data sink. However, the spanning tree structure is not robust against communication errors; when a packet is lost, so is a complete subtree of values. Multipath routing can mask some of these errors, but on the other hand, may aggregate individual sensor values multiple times. This may produce erroneous results when dealing with duplicate- sensitive aggregates, such as SUM, COUNT, and AVERAGE. In this talk, I will present and analyze two new fault tolerant schemes for duplicate-sensitive aggregation in WSNs: (1) Cascaded RideSharing and (2) Diffused RideSharing. These schemes use the available path redundancy in the WSN to deliver a correct aggregate result to the data sink. Compared to state-of-the-art, our schemes deliver results with lower root mean square (RMS) error and consume much less energy and bandwidth. RideSharing can consume as much as 50% less resources than hash-based schemes, such as SKETCHES and Synopsis Diffusion, while achieving lower RMS for reasonable link error rates. (Joint work with Sherif Khattab, Jose' Brustoloni, Daniel Mossé, and Rami Melhem -- dry run for SECON presentation).

Biography of Speaker

Sameh Gobriel received his BE in Electronics and Electrical Communications Engineering from Cairo University in 1999. He joined the University of Pittsburgh in Spring 2003 and is currently pursuing a PhD degree in the Computer Science Department. His research interests include energy-efficient design of wireless data networks, adhoc networks and sensor networks, fault-tolerant wireless networks and large scale wireless networks. He has been awarded the Andrew Mellon Predoctoral Fellowship for the academic year (2005-2006). Mr. Gobriel is a student member of IEEE.