Comprehensive survey on self-organizing cellular network approaches applied to 5G networks

Hybrid Self-Organizing Networks: Evolution, Standardization Trends, and a 6G Architecture Vision

“…The present paper complements the work of Fourati et al [2] and Bayazeed et al [6] by providing a comprehensive overview of the self-organization history from the late 1940s. We then emphasize the importance of hierarchy with different time scales, decoupling of different hierarchy levels (i.e., time scale separation) or between subsystems at the same hierarchy level (i.e., separation using orthogonality), multiple degrees of centralization, and negotiation between various system parts as promising design paradigms to build the components of SONs and achieve a conflict-free behavior by design as opposed to reactive and proactive methods that can be too slow in dynamic situations.…”

“…Federated learning can simplify network automation by processing learning models (e.g., on COTS hardware installed at the edge) instead of handling large training datasets to reduce the time and energy costs of the proactive self-coordination. Further, transfer learning will allow capitalizing on the experience gained in avoiding or resolving previous SON conflicts to address new but similar ones [2].…”

“…Harmonized Achieving a profound technology shift through large scale adoption of renewable-powered system units energy efficiency [2]. One way to resolve the potential conflicts is to define priorities.…”

“…Self-organization [1], [2] is a general term that covers any kind of autonomous restructuring of a system and is, therefore, the highest and most general in the hierarchy of all technical systems. Thus, the main objective of SONs in communication systems is to reduce capital expenditures (CAPEX) and operational expenditures (OPEX) through automating as many features as possible, spanning multiple network components and various engineering phases.…”

“…We then emphasize the importance of hierarchy with different time scales, decoupling of different hierarchy levels (i.e., time scale separation) or between subsystems at the same hierarchy level (i.e., separation using orthogonality), multiple degrees of centralization, and negotiation between various system parts as promising design paradigms to build the components of SONs and achieve a conflict-free behavior by design as opposed to reactive and proactive methods that can be too slow in dynamic situations. We particularly delve into the definition of the concept of weakly or loosely coupled systems referred to as Hybrid SONs (H-SONs) in [2] and [6], which are gaining importance within the current network landscape. From a standardization perspective, there has been insufficient interest in self-coordination aspects and the focus has been on the 3rd Generation Partnership Project (3GPP), the International Telecommunications Union-Telecommunication Standardization Sector (ITU-T), and the European Telecommunications Standards Institute (ETSI) activities [5], thus overlooking many initiatives driven by other standardization development organizations (SDOs).…”