Ray-traced digital twins are increasingly used to plan where cellular-connected uncrewed aerial vehicles (UAVs) can fly. In this paper, we build a Sionna RT digital twin around Raleigh, NC, with 18,591 buildings and two overlapping sub-1 GHz operator networks, and study the downlink signal-to-interference-plus-noise ratio (SINR) of UAVs at 40-300 m. We show that the Monte Carlo radio-map solver of Sionna RT misses distant line-of-sight (LOS) interferers on aerial planes. With $10^7$ rays per sector and 5 m cells, it therefore underestimates the coverage at low SINR thresholds and overestimates it at high thresholds, by up to 26 percentage points at $\pm$2 dB and 50-100 m. Using a LOS-aware deterministic engine validated with Sionna's path solver, we then develop a stochastic geometry model with strongest-sector association and own-site leakage that matches the engine without fitting. The analysis shows that the interference grows logarithmically with the modeled network radius, so a twin that omits distant LOS sites overestimates the coverage, and that altitude mainly reduces the coverage at high SINR thresholds. Finally, selecting the better of two operators raises the minimum SINR along the best corridor by 1.0-3.9 dB up to 100 m.
Saad Masrur, M M Sadman Shafi, Md Sharif Hossen, Ismail Guvenc
原文摘要
Advanced air mobility (AAM) is expected to organize unmanned aerial vehicle (UAV) traffic into corridors at multiple altitudes. In this paper, we study the downlink (DL) and uplink (UL) capacity of a multi-layer Manhattan-grid corridor mesh served by a terrestrial fifth-generation (5G) new radio (NR) macro network. The corridor spacing and the numbers of layers, UAVs, and base stations are configurable. We combine the 3GPP aerial channel and antenna models, correlated UAV mobility, and frequency-selective fading with an NR physical-layer abstraction that includes channel aging and link adaptation. Results show that UAVs above 90 m experience a DL signal-to-interference-plus-noise ratio (SINR) about 17 dB below that of ground users, and that a dense macro network with $10^\circ$ downtilt leaves 17-29% of corridor positions without DL service under full-buffer load, regardless of corridor spacing. On a common layout, the carrier frequency (700 MHz, 3.5 GHz, or 7.2 GHz) changes the UAV SINR by less than 0.5 dB, since the corridor links are strongly interference-limited. The UL is the bottleneck: at 85% satisfaction, a 20 MHz carrier supports only about 3.4-4.1 UAVs/km$^2$ with 4 Mb/s of UL video per UAV.