SOUTENANCE : Thèse de Moazzam Islam Tiwana

vendredi 19 novembre 2010 :
« Automated RRM Optimization of LTE networks using Statistical Learning« . Moazzam a effectué ses travaux de thèse au sein de Orange Labs à Issy les Moulineaux.

La soutenance aura lieu le 19 novembre 2010 à 16h à l’Université Pierre et Marie Curie (UPMC), Campus Jussieu, 4 place Jussieu 75005, dans la salle 25-26/101.

Jury:

Président:
Prof. Guy PUJOLLE, Université Pierre et Marie Curie

Rapporteurs:
Associate Prof. Raquel BARCO, Université de Malaga Dr. Bruno TUFFIN, INRIA Rennes

Examinateur:
Dr. Adam OUOROU, Orange Labs
Directeurs de thèse:
Prof. Tijani CHAHED, TELECOM SudParis
Dr. Berna SAYRAC, Orange Labs
Dr. Zwi ALTMAN, Orange Labs

Abstract:

The mobile telecommunication industry has experienced a very rapid growth in the recent past. This has resulted in significant technological and architectural evolution in the wireless networks. The expansion and the heterogenity of these networks have made their operational cost more and more important. Typical faults in these networks may be related to equipment breakdown and inappropriate planning and configuration. In this context, automated troubleshooting in wireless networks receives a growing importance, aiming at reducing the operational cost and providing high-quality services for the end-users.

Automated troubleshooting can reduce service breakdown time for the clients, resulting in the decrease in client switchover to competing network operators. The Radio Access Network (RAN) of a wireless network constitutes its biggest part. Hence, the automated troubleshooting of RAN of the wireless networks is very important. The troubleshooting comprises the isolation of the faulty cells (fault detection), identifying the causes of the fault (fault diagnosis) and the proposal and deployement of the healing action (solution deployement).

First of all, in this thesis, the previous work related to the troubleshooting of the wireless networks has been explored. It turns out that the fault detection and the diagnosis of wireless networks have been well studied in the scientific literature. Surprisingly, no significant references for the research work related to the automated healing of wireless networks have been reported. Thus, the aim of this thesis is to describe my research advances on « Automated healing of LTE wireless networks using statistical learning ». We focus on the faults related to Radio Resource Management (RRM) parameters.

This thesis explores the use of statistical learning for the automated healing process. In this context, the effectiveness of statistical learning for automated RRM has been investigated. This is achieved by modeling the functional relationships between the RRM parameters and Key Performance Indicators (KPIs). A generic automated RRM architecture has been proposed. This generic architecture has been used to study the application of statistical learning approach to auto-tuning and performance monitoring of the wireless networks.

The use of statistical learning in the automated healing of wireless networks introduces two important diculties: Firstly, the KPI measurements obtained from the network are noisy, hence this noise can partially mask the actual behaviour of KPIs. Secondly, these automated healing algorithms are iterative. After each iteration the network performance is typically evaluated over the duration of a day with new network parameter settings. Hence, the iterative algorithms should achieve their QoS objective in a minimum number of iterations.

Automated healing methodology developped in this thesis, based on statistical modeling, addresses these two issues. The automated healing algorithms developped are computationaly light and converge in a few number of iterations. This enables the implemenation of these algorithms in the Operation and Maintenance Center (OMC) in the off-line mode.

The automated healing methodolgy has been applied to 3G Long Term Evolution (LTE) use cases for healing the mobility and intereference mitigation parameter settings. It has been observed that our healing objective is achieved in a few number of iterations. An automated healing process using the sequential optimization of interference mitigation and packet scheduling parameters has also been investigated.
The incorporation of the a priori knowledge into the automated healing process, further reduces the number of iterations required for automated healing. Furthermore, the automated healing process becomes more robust, hence, more feasible and practical for the implementation in the wireless networks.