Energy-Efficient Asset Tracking Using
Wireless Sensor Networks

Sudha Krishnamurthy

A wireless sensor network is primarily a large-scale, decentralized 
information system.  The ability of the sensor nodes to gather information 
from physical environments in an unobtrusive manner has made them 
particularly attractive for use in applications that are often deployed in 
harsh, ad-hoc physical environments, such as battlefield surveillance, 
earthquake monitoring, and environmental monitoring.  On account of the 
highly energy-constrained nature of the sensor devices, energy efficiency 
is an important design goal of any system involving sensor networks.  

I will describe an energy-efficient surveillance system that we have 
developed, which makes use of a network of wireless sensor nodes to detect 
and track different kinds of moving assets.  This system provides two key 
middleware services: a sentry service that extends the lifetime of the 
deployed devices, and an in-network aggregation service that reduces false 
alarms as well as message overhead.  We have demonstrated the use of this 
system for tracking vehicles and personnel by deploying a network of 70 
Berkeley motes (tiny sensor nodes) and I will present a few of the 
experimental results.  I will also describe the design of RESTORE, which 
is an energy-aware, in-network storage middleware for wireless sensor 
networks that I am currently developing.  To achieve energy efficiency and 
graceful degradation, RESTORE partitions a sensor network into zones.  
RESTORE maps each event to a zone, and uses the storage resources in a 
zone to cooperatively store information about one or more events.  Such an 
in-network store is useful in environments in which access to external 
storage units is intermittent.  

Finally, I will briefly describe my current projects that involve the use of radio frequency identification (RFID) for
tracking different assets. The combined use of different technologies, such as RFID and wireless sensor nodes, to identify
and track different assets could potentially result in interesting usage scenarios for several practical applications and this
synergy needs to be explored further.

Bio:

Sudha Krishnamurthy obtained her PhD in Computer Science from the                                
University of Illinois, at Urbana-Champaign in October 2002. She worked                          
as a research associate at the University of Virginia until August 2004,                         
where she was involved in research projects in the area of ad-hoc wireless                       
sensor networks. She is currently employed as a research staff member in                         
the sensors and actuators group at IBM research lab in India, where she is                       
involved in designing solutions and services for using RFID technology                           
in applications that have both business and research impact. She                                 
is interested in research problems that are motivated by practical                               
application scenarios, especially in the areas of distributed systems,                           
pervasive computing, information systems, wireless and mobile computing.