Intelligent cooperation management of multi-radio access technology towards the green cellular networks for the twenty-twenty information society

An unprecedented increase in subscribers and demand for high-speed data are considered a critical step towards the new era of mobile wireless networks, i.e., Fifth Generation (5G), where the legacy mobile communication system will still be operational for a long time in the future. This has subsequently increased the overall energy consumption, operational costs and carbon footprint of cellular networks, due to increase the number of base stations (BSs), which consume the most energy. Switching BSs off/on in accordance with the traffic pattern variations is considered an effective method for improving energy efficiency. However, the main concerns from the network operators are the requirements to switched on/off the BSs, coverage issues and secured the radio service for the affected area. Hence, the main focus of this study is to develop an intelligent cooperation management (switch BSs on/off) within a multi-radio access technology (RAT) environment between a future generation 5G into the existing LTE and UMTS cellular network towards green cellular networks, while guaranteeing maximum cells coverage area during a switch off session. Particle swarm optimisation has been adopted in this study to maximize the cell coverage area under the constraints of the transmission power of the BS ((P_{tx})), the total antenna gain (G), the bandwidth (BW), the signal-to-interference-plus-noise ratio (SINR), and shadow fading ((sigma )). Moreover, the modulation and coding scheme, the data rate, and the energy efficiency are considered. The results have shown that by applying the proposed a dynamic multi-RAT BSs switching off(backslash )on strategy according to the traffic load variations, the daily energy savings of up to 42.3% can be achieved, with guaranteed maximum cells coverage area.