Research Interests: Hahn Le

Over the last few years Peer-to-Peer (P2P) systems have emerged as highly attractive systems supporting many useful large-scale applications and services. They allow the exploitation of enormous untapped resources (such as idle processing cycles, storage, and bandwidth) available at Internet-connected devices, which were previously considered incapable of providing services to others. Participating nodes (peers) form an overlay network and communicate with each other without being controlled by a central authority.

The structures and routing decisions of the most current P2P networks often do not correlate with the Internet infrastructure. In doing so, the tasks of overlay construction and routing become less complicated however, this results in high end-to-end delay for the P2P applications. As a consequence, the P2P networks may not be able to provide stringent Quality of Service (QoS) requirements for a new generation of P2P applications, and thus limit their benefits for the end users. Moreover, the infrastructure ignorance means P2P systems waste Internet resources by adding more than they should to the Internet traffic. This leads to the increase in Internet access costs substantially, and in turn the P2P systems do not scale well.

My first research interest is to construct infrastructure-aware overlay networks. The goal is to overcome the disparity between the overlay and Internet structures in order to maximize the use of network resources and reduce the overlay delay to the P2P applications while maintaining self-organizing, decentralized and self-maintaining characteristics for the systems. This provides a fundamental foundation for Quality of Service (QoS) support (e.g. low latency) for P2P applications and helps develop scalable P2P systems.

P2P technologies have been developed rapidly in all directions with various applications and routing mechanisms, but there has not been a unified architectural framework that provides an efficient structure and organization of major functional tasks for P2P systems. Accordingly, the performance of most P2P systems is far from optimal because they were often designed to resolve a very specific task without considering all major P2P performance aspects.

Moreover, separate development with close structures of these P2P systems prevents interoperability amongst systems. As a consequence, it makes development of a system expensive and limits the provision of tangible benefits for end users because resources and functions in a system cannot be shared with others.

I am interested in developing an open reference model for developing efficient P2P systems. This could be done such as by breaking a comprehensive P2P system into smaller functional tasks/components and by layering the system. In doing so, each component can be tackled individually and efficiently. This creates an opportunity to optimize components and to re-use optimized components. Optimized components then can be stacked together to build a complete system with low cost because the system does not require re-inventing/designing and re-implementing each and every component while achieving optimal performance

This could be a progressive step towards the co-operation and inter-networking between P2P systems, creating potentially enormous resources in a magnitude order of what a P2P system can offer.

Currently overlay networks are situated on top of the fixed Internet. Another interesting research area is extending the Overlay network to other communication networks such as wireless, mobile, ad-hoc networks, especially mobile phone system. With the extension to the mobile phone system, it would allow the integration of the two most exciting and fastest growing communities: the Internet and mobile phone system, opening opportunities for many useful applications and services.

I am keen on extending the overlay network to body area networks and sensor networks to accommodate new applications such as: electronic healthcare systems. My passion is to develop an efficient overlay network across the Internet, mobile phone systems and sensor networks as a unified infrastructure enabling large-scale service deployment seamlessly and efficiently.

My research interests are (but not limited to): mobile, Peer-to-Peer, ad-hoc, sensor networks and applications.