I. Introduction
Terrestrial LTE base stations usually are statically deployed. However, this static deployment limits their usage in key 5G and 5G Beyond applications with surging traffic demands at some hotspot locations (e.g., battlefields and concerts). In addition, the deployed base stations may have been destroyed in natural disasters, e.g., earthquakes, tsunamis, flooding, etc. Emergent communication service are definitely needed for rescue teams to rescue people trapped in disaster areas [9], [19].