Multimedia Networks Group
Networking Research at the University of Virginia
University of Virginia>Computer Science Dept.> Multimedia Networks Group> projects>qos 

      Introduction, Research Statement...

      Faculty, Postdocs, Students, Alumni...

      INDRA, QoSbox, HyperCast, RouteConfig, VintLab, Traffic Engineering...

      QoS Networks, Super-Scalable Multicasting, Hybrid Fiber Coax Networks...


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Quality-of-Service in Multimedia Networks


We study Integrated Services Networks with deterministic and statistical QoS. Currently, our research includes:


Dallas, Jörg


Domenico Ferrari (UCB), Ed Knightly (Rice), Hui Zhang (CMU)

Traffic Characterization

We have worked on "best possible" and "practical" traffic characterizations for deterministic quality-of-service. We have studied a lot of MPEG video traces and looked at fast and accurate characterization methods for MPEG.

Packet Scheduling

We have developed and proved exact admission control tests for Earliest- Deadline-First (EDF) and Static Priority (SP). These results were the first exact admission control tests available for general traffic characterizations.

We have proposed a new packet scheduler, called Rotating Priority Queues (RPQ). RPQ schedulers are built with FIFO queues, which are rotated after fixed time periods. We have showed that, at 155 Mbps, an RPQ video multiplexer with only 10 FIFO queues can support as many MPEG video streams as an EDF multiplexer. Recently, we proposed RPQ+, which overcomes some pathologies of RPQ.


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