Tag Archives: Quality of service

11/06/2014 – Talk by Ivan Stojic

Title: Optimisation of servers with different quality of services
Time: 14:00
Location: Meeting room
Type: Research Result
Speaker: Ivan Stojic

In many applications involving client/server or equivalent architecture, it is possible to vary the quality of services provided by the servers. Dynamic control of the quality of services is an effective mechanism for control of the performance of the system in conditions of varying system load. One of the basic problems involved in applying this mechanism is optimisation of the controlling policy that determines the level of quality of services based on the state of the system. In this seminar, after a brief introduction to Markov chains and basic queueing models, a Markov chain based model of a multiserver queue with processor-sharing discipline and different quality of services is presented. Calculation of the performance indices from the model and the prohibitive complexity of the exact solution are discussed next, motivating the introduction of a simpler model that heuristically approximates the original model and allows for more efficient model solution and optimisation of the controlling policy.

29.04.2013 – Talk by Erol Gelenbe

Title: Towards energy efficient QoS
Time: 13:00
Location: Meeting room
Type: Research Result
Speaker: Erol Gelenbe
Often, papers regarding energy savings in computer systems
and networks discuss average power consumption (in watts) which is
easier to measure and understand than actual energy consumption
(in joules or watt-hours). Furthermore not much attention has yet been devoted
to energy efficiency in conjunction with the quality of service (QoS) delivered
to users. Based on our own work on different architectures including
packet network routing, systems that include multiple servers, cloud computing
and mobile devices, we will show how energy consumption together with
QoS can be optimised for end users.

Brief Bio:
Erol Gelenbe’s curent projects, funded by EU FP7, UK EPSRC and UK MoD,
cover both energy savings in ICT and network security. His recent papers in the
Physical Review and ACM/IEEE journals and conferences, deal with performance and
energy considerations, but also with gene regulatory networks and protein alignment.
He is an IEEE and ACM Fellow, and a member of several national academies
of science and of engineering. He received the ACM SIGMETRICS Life-Time
Achievement Award, the France-Telecom Prize of the French Academy of Sciences,
and several honoris causa doctorates, and decorations from France and Italy.