Nahrstedt Named ACM Fellow for 2012

University of Illinois computer science professor Klara Nahrstedt has been named to the 2012 class of ACM Fellows for her “contributions to quality-of-service management for distributed multimedia systems.”  The ACM Fellows Program celebrates the exceptional contributions of the leading members in the computing field. These individuals have helped to enlighten researchers, developers, practitioners and end-users of information technology throughout the world. The new ACM Fellows join a distinguished list of colleagues to whom ACM and its members look for guidance and leadership in computing and information technology.

Nahrstedt is a leading researcher in multimedia systems, with seminal contributions to quality-of-service (QoS) management for distributed multimedia systems.  QoS is the ability to differentiate between and guarantee different levels of performance across a network for applications, users, or flows of data.  Such guarantees are especially important for streaming multimedia applications, and for when network capacity is limited.

By introducing the concept of QoS brokerage, Nahrstedt’s early work changed how multimedia end-system architectures are designed and built, allowing network peers to negotiate end-to-end QoS “contracts” to guarantee streaming performance.  Her novel QoS adaptation modeled the end-to-end QoS problem based on a control-theoretical approach – the first applications of control theory to multimedia systems – receiving the Leonard C. Abraham Paper Award from the IEEE Communication Society. 

Later, Nahrstedt made fundamental contributions to QoS-based routing.  In 1999, she derived a distributed time and bandwidth sensitive routing scheme that is able to select the network path which has sufficient resources to handle an application’s performance requirements.  She was the first to address the issue of QoS-based routing in ad-hoc networks, opening a new area of work for multimedia researchers.  Her tutorial paper on QoS-based routing in wired networks provided an indispensable overview of that topic, winning the 1999 Best Tutorial Paper Award from the IEEE Communications Society.  Nahrstedt has also made major contributions to QoS in wireless networks, which can be much more unpredictable than wired networks due to changing conditions and interference in the physical environment. 

Currently, Nahrstedt is studying ways to provide QoS guarantees in the challenging context of 3D tele-immersion.  In 3D tele-immersion, geographically separated people interact with each other within a virtual environment that strives to replicate the experience of a face-to-face physical interaction. Naturally, such interaction involves stringent real-time guarantees. In fact, Nahrstedt and her students have been the first to develop many of the metrics and protocols necessary to manage the large video and audio data streams generated by such environments, including the first adaptive real-time 3D multi-stream protocol, view-casting protocols for multi-viewpoint 3D video, and metrics to define the user’s Quality of Experience. 

Nahrstedt, a Ralph M. and Catherine V. Fisher Professor, has been on the faculty of the Department of Computer Science at Illinois since 1995 and has received numerous honors, including the IEEE Communications Society Leonard G. Abraham Prize, the IEEE Computer Society’s Technical Achievement Award, the University Scholar Award, and the Humboldt Research Award, among others. She is also a Fellow of the IEEE.  Since 2009, she has chaired the ACM Special Interest Group on Multimedia.  Her two textbooks are among the most widely used textbooks on multimedia technology.

Writer: Colin Robertson, Department of Computer Science, colinr [at] illinois [dot] edu, 217/265-6403.
Contact: Klara Nahrstedt, Department of Computer Science, klara [at] illinois [dot] edu, 217/244-6624.