Einladung zur öffentlichen Disputation

von Herrn Junyu Lai

verlegt auf
Donnerstag, 6.September 2012 16:45 Uhr
Informatikum, Vogt-Kölln-Straße 30, Raum F-534

"Evaluation and Improvement of TV Channel Availability for IPTV Services"

Abstract:

Recently, Internet Protocol Television (IPTV) has become increasingly popular across the globe. It is widely believed that IPTV is capable of providing much richer TV viewing experience than conventional TV systems by means of delivering broadcast-style TV programs (probably, extended by on-demand contents) in a more interactive and personalized way. In a typical IPTV system, a large number of TV channels (>100) are usually offered simultaneously and possibly also in high quality (e.g., in HDTV format). Therefore, bottlenecks in the underlying transmission network may occur which can cause some unpopular TV channels to be temporarily unavailable, and can consequently degrade subscribers' Quality of Experience (QoE).

In this thesis, firstly, we focus on the difficult problem of predicting the availability of IPTV services in a typical DSL-based IPTV system. A Monte Carlo Simulation model is elaborated to evaluate the user Call Blocking Probability (CBP) which is applied as the measure of the IPTV service availability. As an important contribution, our studies are carried out not only in stationary scenarios (as most conventional studies did), but also in practically very relevant peak-hour scenarios. Secondly, in order to decrease the CBP and consequently to improve user QoE, we resort to solutions with smarter use of the bandwidth resources in bandwidth capacity limited IPTV systems. As the major contribution of the thesis, we propose two innovative algorithms, namely the TV Channel Access Control (TCAC) scheme and the intentional Switching Delay (iSD) admission control method. Comprehensive case studies are conducted and show that the two algorithms are very effective. In addition, our proposed algorithms are also easy to be implemented in practical systems, and can help the service providers to enhance the QoE of their subscribers.

 

—Vortrag auf Englisch—
Alle Mitglieder des Fachbereichs Informatik sind zu dieser öffentlichen Veranstaltung herzlich eingeladen.

Kontakt:

Prof. Dr. Christopher Habel
Vorsitzender des Promotionsprüfungsausschusses