A Method for the Detection of QoS Degradation in UMTS Networks

UMTS Services Accessibility is a daily concern for network operators. Proper network resource dimensioning allows maximizing the operator investment and enhances user experience. In the case of a resource shortage, it is very helpful to decide which resource is mainly responsible for the downgrade, in order to upgrade this particular resource. In this article, authors model UTRAN accessibility, once known the system resources, the different service''s resource consumptions and each service''s traffic. The model is validated through comparison between theoretical and real accessibility, and an accuracy enhancement is achieved using loopback correction in several real case studies. Results show that the proposed model matches the binary decision of degraded or non- degraded node with errors below 10% and it is able to suggest the most congested resource each time.

I. Introduction

Until now, legacy mobile networks needed to attend just one type of service. Dimensioning the resource consumption and thus estimating the blockage was easily performed by Erlang B models. Present UMTS networks must attend multiple service scenarios, where each service has a different amount of resource consumption. Thus, new dimensioning models must be addressed in order to detect the aggregated consumption, and by extension, the overall system blockage (or its complementary, the accessibility).