A coordination framework for self-organisation in LTE networks

Abstract

Self-organising Networks (SON) as introduced for 3G Long Term Evolution (LTE) will typically involve several different SON functions. These functions are not necessarily aware of each other and may have complex relations and interdependencies, for example, conflicting parameter settings, depending on their design and approach. Coordination of SON functions may become necessary in order to harmonise the actions of SON functions and allow for a stable and reliablebehaviour of the SON system. This paper describes different conflict types, harmonisation approaches to avoid and resolve conflicts, and a functional framework with different roles to achieve harmonisation. An exemplary case study is given. The paper concludes that, in case several conflicting SON functions are implemented in a network, a SON Coordinator may be beneficial to prevent from network instabilities and/or to improve the performance.

LTE-advanced self-organizing network conflicts and coordination algorithms

“…However, none of these works provide comprehensive identification, annotation and classification of SON function conflicts. Some Self-Coordination mechanisms for SON are described in [9]. However, [9] does not identify the application of these Self-Coordination mechanisms for specific SO function conflicts.…”

“…Some Self-Coordination mechanisms for SON are described in [9]. However, [9] does not identify the application of these Self-Coordination mechanisms for specific SO function conflicts. In [10], for the first time authors have identified and categorised SON function conflicts, based on different criteria such as the network deployment, the Key Performance Indicators, the measurement and logical dependencies, the output parameters' direction/magnitude, etc.…”

Self-coordination of parameter conflicts in D-SON architectures: a Markov decision process framework

“…When they are executed concurrently in the same or different network elements, the impact of their interactions is not easy to be predicted, and unwanted effects may occur. The risk of unacceptable oscillations of configuration parameters or undesirable performance results increase with the number of SON functions, so that it is considered necessary to define and implement a self-coordination framework [3, 4,8].…”

“…A preventive coordination mechanism that uses policy-based decisionmaking has been proposed in [10]. Guard functions have been proposed in [4] to detect undesirable network behaviors and trigger countermeasures. Decision trees have been proposed in [20] for properly adjusting remote electrical tilt (RET) and transmission power.…”

“…In 3GPP, this kind of negative interactions, which affect the system performances, is referred to as SON function conflict, and the general framework to solve them is referred to as self-coordination. The literature on SON mainly focuses on individual SON function design, [1][2][3] while some initial work on self-coordination functions can be found in [4][5][6] and [7] where the authors focused on the identification and classification of different conflict types. Algorithmic solutions [8,9] and implementation challenges [10] have been recently discussed in literature.…”