Design and evaluation of self-healing solutions for future wireless networks

Abstract

This doctoral dissertation is aimed at the creation of comprehensive and innovative Self-Organizing Networks (SON) solutions for the Network Management of future wireless networks. More specifically, the thesis focuses on the Self-Healing (SH) part of SON. Faults can appear at several functional areas of a complex cellular network. However, the most critical domain from a fault management viewpoint is the Radio Access Network (RAN). The fault management of network elements is not only difficult but also imposes high costs both in capital investment (CAPEX) and operational expenditures (OPEX). The SON concept has emerged with the goal to foster automation and to reduce human involvement in management tasks. SH is the part of SON that refers to autonomous fault management in wireless networks, including performance monitoring, detection of faults and their causes, triggering compensation and recovery actions, and evaluating the outcome. It improves business resiliency by eliminating disruptions that are discovered, analyzed and acted upon. With the advent of 5G technologies, the management of SON becomes more challenging. The traditional SH solutions are not sufficient for the future needs of the cellular network management because of their reactive nature, i.e., they start recovering from faults after detection instead of preparing for possible faults in a preemptive manner. The detection delays are especially problematic with regard to the zero latency requirements of 5G networks. In order to address this challenge, the existing SON enabled networks need to be upgraded with additional features. This situation pushes operators to upgrade their SONs from reactive to proactive response and opens doors for further reseach on SON and SH. This dissertation provides several contributions to this direction.