Network and Multimedia Systems Lab (NMSL)

Welcome to the Network Systems Lab at SFU!

We are interested in the broad area of computer networking and distributed systems. We develop algorithms and protocols to enhance the performance of networks, especially the Internet, and to efficiently distribute multimedia content (e.g., video and audio objects) to large-scale user communities. The Network Systems Lab is led by Dr. Mohamed Hefeeda, and is affiliated with the Network Modeling Group at SFU.

Our current research interests include multimedia networking, peer-to-peer systems, wireless sensor networks, and network security. Brief description and links to currently active projects are given below.

Multimedia Networking

We are focusing on distributed streaming in dynamic environments in which a receiver could be served by multiple senders. We are developing models to understand the characteristics (rate-distortion curves) of scalable video streams. We are designing algorithms to optimize streaming quality for heterogeneous (wired and wireless) clients.

• Scalable Multimedia Streaming

• Streaming to Wireless and Mobile Devices

• Content-Aware Adaptive Streaming

Peer-to-Peer Systems

We are exploring the applicability of the P2P paradigm to build cost-effective content distribution systems. Problems such as sender selection, adaptive object replication, and content caching are being studied. We are also developing models to analyze the new characteristics of the P2P traffic and the impact of these characteristics on the cache replacement policies and object replication strategies. Furthermore, we are devising analytic models to study the dynamics of the system capacity and the impact of various parameters on it.

• pCDN: Peer-assisted Content Distribution Network

• Modeling and Caching of P2P Traffic

Wireless Sensor Networks

We are developing coverage and connectivity maintenance protocols that consider probabilistic (i.e., more realistic) sensing and communication models. We are also designing protocols that provide controllable degrees of coverage (k-coverage).

• Probabilistic Coverage and Connectivity

• K-Coverage and its Application to Forest Fire Detection

Network Security

We are exploring network monitoring techniques to detect and thwart intrusion and denial-of-service attacks in their early stages by observing unusual traffic patterns injected by such attacks. We are studying the security of multimedia streaming systems that employ multi-layer and fine-grain scalable video streams.

• Detecting DoS Attacks and Service Violations in QoS-enabled Networks

• Security of Scalable Multimedia Streams