Separation of Control and Data Transmissions in 5G Networks may not be Beneficial

TL;DR

This study challenges the assumed energy efficiency benefits of separating control and data transmissions in 5G networks, showing limited savings and highlighting the advantages of on-demand small cell deployment.

Contribution

It provides a detailed analysis demonstrating that separation architectures offer minimal energy savings compared to traditional systems, especially in CloudRAN settings, and advocates for on-demand small cell usage.

Findings

Energy savings of separation are under 17% compared to legacy systems.

In CloudRAN, separation reduces energy consumption by only about 7%.

Most small cells remain active during nights to handle data loads.

Abstract

The logical separation of control signaling from data transmission in a mobile cellular network has been shown to have significant energy saving potential compared with the legacy systems. As a result, there has been a lot of focus in recent years on development and realization of separation architectures. Our study, however, shows that the energy savings of separation architecture remain under 16-17% when compared with legacy systems and this gain falls to a mere 7% when both architectures are realized under a CloudRAN (CRAN) setting. Moreover, when we strategically place some small base-stations (SBSs) to cover the area in a densely deployed scenario and allow all other base-stations (BSs) to be used only on-demand, the system consumes much less energy than the separation architecture. While we expected that most equipment would be shut down during nights, our study shows that around 70% of the small cells are required to be active to serve randomly distributed minimum data load, i.e., active mobile equipment. Contemporary mobile traffic is predominantly data which does not go to extremely low levels during nights. We discuss, in detail, the assumptions, their implications, and the effects of system parameter values on our conclusions.