Chapter 25
Self-Optimizing Networks
25.1 Introduction
The provision of Self-Optimizing Network (SON) functions is one of the key differentiators of LTE compared to previous generations of cellular systems such as UMTS and GSM. Self-optimization of the network is a tool to derive the best performance in a cost-effective manner, especially in changing radio environments. It allows the network operator to automate key aspects of the network configuration processes, and thus reduces the need for centralized planning and human intervention. For these reasons, this feature has been given a high priority and was a cornerstone around which the LTE radio, S1 and X2 procedures were designed. This makes SON functionality particularly efficient in the LTE system. The involvement of the User Equipment (UE) in the SON functionality of LTE is another key contributor to its success.
This chapter starts with an explanation of the Automatic Neighbour Relation (ANR) Function, the functionality for self-configuration of the eNodeB and MME1 and the automatic Physical Cell Identity (PCI) configuration as natively implemented within the basic S1 and X2 interface procedures.2 These three SON functions, which were included in Release 8, are of particular relevance for the initial deployment of an LTE network.
The chapter then explores other SON functions developed in Release 9 which are designed to optimize deployed LTE networks, such as the Mobility Load Balancing (MBL), Mobility Robustness ...
