'CSCAN Network' Research Student Profile

Dr Frank Weber PhD

CSCAN Network Research Student

Brief biographical information

Quality of Service optimisation framework for Next Generation Networks

Within recent years, the concept of Next Generation Networks (NGN) has become
widely accepted within the telecommunication area, in parallel with the migration of
telecommunication networks from traditional circuit-switched technologies such as
ISDN (Integrated Services Digital Network) towards packet-switched NGN. In this
context, SIP (Session Initiation Protocol), originally developed for Internet use only,
has emerged as the major signalling protocol for multimedia sessions in IP (Internet
Protocol) based NGN.


One of the traditional limitations of IP when faced with the challenges of real-time
communications is the lack of quality support at the network layer. In line with NGN
specification work, international standardisation bodies have defined a sophisticated
QoS (Quality of Service) architecture for NGN, controlling IP transport resources
and conventional IP QoS mechanisms through centralised higher layer network
elements via cross-layer signalling.


Being able to centrally control QoS conditions for any media session in NGN
without the imperative of a cross-layer approach would result in a feasible and less
complex NGN architecture. Especially the demand for additional network elements
would be decreased, resulting in the reduction of system and operational costs in
both, service and transport infrastructure.


This thesis proposes a novel framework for QoS optimisation for media sessions in
SIP-based NGN without the need for cross-layer signalling. One key contribution of
the framework is the approach to identify and logically group media sessions that
encounter similar QoS conditions, which is performed by applying pattern
recognition and clustering techniques. Based on this novel methodology, the
framework provides functions and mechanisms for comprehensive resource-saving
QoS estimation, adaptation of QoS conditions, and support of Call Admission
Control. The framework can be integrated with any arbitrary SIP-IP-based real-time
communication infrastructure, since it does not require access to any particular QoS
control or monitoring functionalities provided within the IP transport network.
The proposed framework concept has been deployed and validated in a prototypical
simulation environment. Simulation results show MOS (Mean Opinion Score)
improvement rates between 53 and 66 percent without any active control of transport
network resources.


Overall, the proposed framework comes as an effective concept for central controlled
QoS optimisation in NGN without the need for cross-layer signalling. As such, by
either being run stand-alone or combined with conventional QoS control
mechanisms, the framework provides a comprehensive basis for both the reduction
of complexity and mitigation of issues coming along with QoS provision in NGN.

Dr Frank Weber

Director of studies: Prof Dr Woldemar Fuhrmann
Other supervisors: Prof Dr Ulrich Trick, Dr Bogdan Ghita, Prof Dr Udo Bleimann

Conference papers

3 Conference papers

Internal publications

3 Internal publications

6 publication(s) - all categories.