Research in Multimedia Systems at UNC

Relatively inexpensive hardware for processing audio and video data is rapidly becoming available for personal computers and workstations. At the same time, greater network bandwidth at lower prices is making its way to the desktop. These developments have stimulated interest in distributed applications that require new capabilities for processing streams of digitized audio and video data. For example, we have developed a workstation-based conferencing system that provides audio and video links between workstations and supports sharing of existing single-user applications between multiple users.

To realize the full potential of these applications, real-time communication and computation services are often required — services that do not exist in most desktop computing environments. This research seeks to develop systems infrastructure for multimedia applications. The current focus is on network and operating system support for the real-time transmission and processing of audio and video data in a distributed system.

This research is carried out by the Distributed and Real-Time Systems (DiRT) research group.

Current Projects & Students

Active queue management for real-time multimedia networking — Mark Parris
Adaptive, rate-based scheduling — Steve Goddard
Traffic measurement and charcterization of the NC GigaPOP — Don Smith

Faculty

Kevin Jeffay, S.S. Jones Professor of Computer Science
F. Donelson Smith, Research Professor

Related Research Projects at UNC

Selected Papers (Listed in reverse chronological order)

(Click here for an alphabetical listing of all papers stored on-line, or a list papers on-line sorted by publication venue (conference/journal). Also, copies of slides for talks about some of these papers are available on-line. Click here for a list.)

Beyond Audio and Video: Multimedia Networking Support for Distributed, Immersive Virtual Environments

EUROMICRO 2001, September 2001.Get: full citation and abstract – or – PostScript (compressed) – or – PDF copy of this paper.(A copy of the slides for the talk presented at the conference is also available.)

Experiments in Best-Effort Multimedia Networking for a Distributed Virtual Environment

ACM/SPIE Multimedia Computing and Networking 2001, January 2001.Get: full citation and abstract – or – PostScript (compressed) – or – PDF copy of this paper.

(A copy of the slides for the talk presented at the conference is also available.)

Responsive vs. Unresponsive Traffic: Active Queue Management for a Better-Than-Best-Effort Service

Technical Report, September 2000.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Towards a Better-Than-Best-Effort Forwarding Service for Multimedia Flows

IEEE Multimedia, December 1999.Get: full citation and abstract and/or PostScript/PDF copies of the paper.

Application-Level Measurements of Performance on the vBNS

IEEE Intl. Conference on Multimedia Computing and Systems, June 1999.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Lightweight Active Router-Queue Management for Multimedia Networking

ACM/SPIE Multimedia Computing and Networking 1999, January 1999.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

(A copy of the slides for the talk presented at the conference is also available.)

A Better-Than-Best-Effort Service for Continuous Media UDP Flows

Intl. Workshop on Network and Operating System Support for DigitalAudio and Video, July 1998.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

(A copy of the slides for the talk presented at the conference is also available.)

A Two-Dimensional Audio Scaling Enhancement to an Internet Videoconferencing System

Intl. Workshop on Audio-Visual Services over Packet Networks, September 1997.Get: full citation and abstract – or – PostScript (compressed) – or – PDF copy of this paper.

The Performance of Two-Dimensional Media Scaling for Internet Videoconferencing

Intl. Workshop on Network and Operating System Support for DigitalAudio and Video, May 1997.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

(A copy of the slides for the talk presented at the conference is also available.)

On the Duality between Resource Reservation and Proportional Share Resource Allocation

ACM/SPIE Multimedia Computing and Networking 1997, February 1997.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

A General Framework for Continuous Media Transmission Control

IEEE Conference on Local Computer Networks, October 1996.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

A Router-Based Congestion Control Scheme For Real-Time Continuous Media

Intl. Workshop on Network and Operating System Support for DigitalAudio and Video, April 1996.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

A Rate-Based Execution Abstraction For Multimedia Computing

Intl. Workshop on Network and Operating System Support for DigitalAudio and Video, April 1995.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

An Empirical Study of a Jitter Management Scheme for Video Teleconferencing

ACM Multimedia Systems, January 1995.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Two-Dimensional Scaling Techniques For Adaptive, Rate-Based Transmission Control of Live Audio and Video Streams

ACM Multimedia ’94, October 1994.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Adaptive, Best-Effort Delivery of Live Audio and Video Across Packet-Switched Networks (VHS Video)

ACM Multimedia ’94, October 1994.Get: full citation and abstract – or – PostScript copy of the abstract, or an MPEG clipof the video (~3 Mbytes).

Transport and Display Mechanisms For Multimedia Conferencing Across Packet-Switched Networks

Computer Networks and ISDN Systems, July 1994.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

On Latency Management in Time-Shared Operating Systems

IEEE Workshop on Real-Time Operating Systems and Software, May 1994Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Queue Monitoring: A Delay Jitter Management Policy

Intl. Workshop on Network and Operating System Support for Digital Audio andVideo, November 1993.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Adaptive, Best-Effort, Delivery of Audio and Video Data Across Packet-Switched Networks

Intl. Workshop on Network and Operating System Support for Digital Audio andVideo, November 1992.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

On Kernel Support for Real-Time Multimedia Applications

IEEE Workshop on Workstation Operating Systems, April 1992.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Kernel Support for Live Digital Audio and Video

Intl. Workshop on Network and Operating System Support for Digital Audio andVideo, November 1991 (also in Computer Communications, July 1992).Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

System Design for Workstation-Based Conferencing With Digital Audio and Video

IEEE Conference on Communication Software: Communications for DistributedApplications and Systems, April 1991.Get: full citation and abstract.

Designing a Workstation-Based Conferencing System Using the Real-Time Producer/Consumer Paradigm

Intl. Workshop on Network and Operating System Support for Digital Audio andVideo, November 1990.Get: full citation and abstract.