On Millimeter Wave and THz Mobile Radio Channel for Smart Rail Mobility

TLDR

Rail traffic is transitioning to smart rail mobility, demanding seamless high‑data‑rate wireless connectivity with dozens of gigahertz bandwidth, which drives exploration of underutilized millimeter‑wave and terahertz bands. This paper clarifies the motivations for developing millimeter‑wave and terahertz communications for railways by defining the applications and scenarios essential to smart rail mobility. Ray‑tracing simulations at 100 GHz indicate that high‑gain directional antenna beams, dynamic beamforming, and advanced handover design are essential for feasible terahertz communications in smart rail mobility.

Abstract

As a widely acknowledged efficient and green transportation model, rail traffic is expected to evolve into a new era of “smart rail mobility” whereby infrastructure, trains, and travelers will be interconnected to achieve optimized mobility, higher safety, and lower costs. Thus, a seamless high-data rate wireless connectivity with up to dozens of gigahertz bandwidth is required. Such a huge bandwidth requirement motivates the exploration of the underutilized millimeter (mm) wave and terahertz (THz) bands. In this paper, the motivations for developing millimeter wave and THz communications for railway are clarified by first defining the applications and scenarios required for smart rail mobility. Ray-tracing simulations at 100 GHz imply that to form high-gain directional antenna beams, dynamic beamforming strategies and advanced handover design are critical for the feasibility of THz communications to enable smart rail mobility.