PhD Thesis Proposal Defence


"Quality of Service (QoS) in Computer Networks"

by

Mr. Lei Zhang


Abstract:

Motivated and driven by the development of real-time multimedia
applications, Quality of Service (QoS) has been a hot research area in
computer networks for quite a long time. Over the past years, different
models, namely DiffServ and IntServ, and many algorithms have been
proposed for QoS.

In this proposal, a new multi-layer framework is proposed for QoS. The
framework is composed of three major layers, namely the routing layer, the
network layer, and the application layer.

Problems in each layer are then defined and studied. They are: online QoS
routing problems in the routing layer, VPN provisioning problems and
location management problems in mobile ad-hoc networks in the network
layer, and cooperative downloading schedule problem in peer-to-peer
networks in the application layer.

In the routing layer, we consider the online QoS routing problem of
setting up QoS guaranteed paths in a network, where routing requests
arrive one at a time and future demands are unknown. The objective is to
minimize the call blocking probability due to insufficient network
resources to support the required quality of service. A scheme, called the
Maximum r-Ability Preserving Scheme (MAPS), is proposed to protect those
critical links/paths that are crucial for future requests.

In the network layer, we are mainly concerned about those supporting
technologies which can provide underlying systems or service models for
the upper routing layer. Two problems are studied. One is the provisioning
problem with enhanced Hose model in Virtual Private Networks (VPN) and the
other is the location management problem in Mobile Ad-hoc Networks
(MANET). For the first problem, we enhanced the hose model specification
to support delay requirements at the VPN endpoints. For the second one, we
proposed an integrated location management and location-aided routing
system which uses location information as a guidance in QoS routing. In
the application layer, we study the downloading problem of large-scale
files in P2P networks. Proximity is introduced to minimize the average
downloading time and to maximize uploading link capacities.


Date:     		Thursday, 18 May 2006

Time:                   4:00p.m.-6:00p.m.

Venue:                  Room 3598
			lifts 27-28

Committee Members:      Dr. Jogesh Muppala (Supervisor)
                        Dr. Gary Chan (Chairperson)
			Dr. Brahim Bensaou
			Dr. Qian Zhang


**** ALL are Welcome ****