Analysis of High Altitude Platform Stations for network reliability improvement

Over the last decade, the global volume of data exchanged through Radio Access Networks (RANs) has grown significantly. This trend, along with an increase in blackouts and power grid failures, has highlighted the importance of reliability and resilience in modern wireless networks. Typically, the Base Stations (BSs) in RANs are powered by the electricity grid, and in the event of an outage, they rely on expensive backup batteries. Once these batteries are depleted, the service they provide is interrupted. To address the potential interruption of RAN services due to power loss at BSs, we propose using a revolutionary and disruptive technology: High Altitude Platform Stations (HAPSs). HAPSs can be equipped with solar panels and batteries to ensure energy autonomy, as well as networking hardware to operate as aerial RAN Base Stations (BSs). In the event of power grid shortages, we offload part of the traffic normally handled by terrestrial BSs to the HAPS. Our work presents the results of a study conducted by simulating an urban RAN that includes several terrestrial BSs and a HAPS. The simulated RAN provides both Long Term Evolution (LTE) and New Radio (NR) connectivity, using real traffic data provided by an Italian network operator. We investigate different HAPS offloading strategies aimed at improving the energy autonomy of terrestrial BSs. The results demonstrate that integrating HAPS into modern urban RANs, along with the use of targeted offloading strategies, significantly improves the energy autonomy of terrestrial BSs and enhances the overall reliability of the network.