COLLOQUIUM
             Computer Science Department, Boston University

Speaker: Eylem Ekici
         The Ohio State University

Date:  Monday, October 17, 2005
Time:  11:00
Place: Room MCS 135, 111 Cummington Street 
       (for directions, see www.cs.bu.edu/colloquium)

Title: Application-Level Service Guarantees for Wireless Sensor Networks

Abstract:

Since their first introduction, the deployment scenarios for 
Wireless Sensor Networks (WSNs) have evolved significantly. 
While the initial scenarios for WSNs proposed simple sense and 
send type applications, newer proposals, such as video sensor 
networks, envision applications with stringent requirements. 
However, the evolution in the applications was not followed by 
significant changes in the constraints of WSNs: Large network 
scale, limited power supplies, and limited processing and 
communication capabilities must still be taken into account 
during the design and operation of solutions developed for WSNs.  
The demands of these new applications in resource-constrained WSNs 
cannot be met by isolated approaches. A strong collaboration not 
only between communication layers but also between the application 
and the communication mechanisms must be established to fully utilize 
all available resources.

In this talk, our approach to application-level service guarantees 
in WSNs is presented. The talk focuses on two main strands of 
research: In the first part, a cross-layer communication protocol 
will be introduced that provides probabilistic delay and reliability 
bounds. Based on local observations and decisions, the MMSPEED 
protocol aims to deliver packet-level end-to-end delay and delivery 
guarantees without sacrificing efficiency. The statistical 
observations are leveraged to predict the network conditions 
along the remaining part of the path. These predictions are 
then used to adjust local operation parameters. In the second 
part, a new collaborative in-network processing mechanism for 
WSNs is introduced. The proposed mechanisms use the collective 
processing power of sensors in a cluster to deliver application-level 
deadline and energy consumption guarantees. Using a novel application 
representation, communication and computation events are scheduled 
jointly inside a cluster. This representation also ensures 
application-dependence of the proposed solutions, which is a 
common shortcoming of various existing proposals. A discussion 
on the joint use of these two seemingly distinct methods to 
provide application-level QoS will conclude the talk.

Biography:

Eylem Ekici has received his BS and MS degrees in Computer Engineering 
from Bogazici University, Istanbul, Turkey, in 1997 and 1998, 
respectively. He received his Ph.D. degree in Electrical and 
Computer Engineering from Georgia Institute of Technology, 
Atlanta, GA, in 2002. Currently, he is an assistant professor 
in the Department of Electrical and Computer Engineering of the 
Ohio State University, Columbus, OH. Dr. Ekici's current research 
interests include wireless sensor networks, next generation wireless 
systems, and vehicular communication systems, with a focus on routing 
and medium access control protocols, resource management, and analysis 
of network architectures and protocols. He also conducts research on
interfacing of dissimilar networks.

Host: Ibrahim Matta