Future of UAV communication in 6G networks: AI-native architecture, reconfigurable intelligent surface integration, and security frameworks

Unmanned Aerial Vehicles (UAVs) are transitioning from niche platforms to integral nodes within sixth-generation (6G) wireless infrastructure, yet the communication challenges introduced by high mobility, three-dimensional propagation, and strict onboard resource limits remain incompletely addressed in the existing literature. This survey examines UAV communication for 6G across four pillars, namely the RIS-assisted physical layer, AI-native mobility management, millimeter-wave and terahertz spectrum extension, and post-quantum security, within the Space–Air–Ground integrated networks. A documented search protocol defines the corpus, and an original simulation study complements the analysis with quantitative evaluation. The simulation shows that optimal RIS phase control shifts the outage curve by about 10 dB and raises ergodic spectral efficiency by 44% as the surface grows from 16 to 256 elements, that a 3-bit phase shifter lies within 0.22 dB of continuous control, and that these conclusions hold under Rician, Rayleigh, and Nakagami-m fading, with the analytical model agreeing to within 0.79 of a decade against ray-traced channels from the DeepMIMO dataset. The study also identifies a cross-layer timing constraint, from the 1.58 ms channel coherence to the 3.59 ms post-quantum handshake against the 1 ms URLLC budget, and grades technology readiness by separating laboratory from field maturity.