Scalable Multi-User Terahertz Wireless Networks With Angularly Dispersive Links

THz communication can realize the next order of magnitude in data rate and user densities due to the availability of wide THz-scale spectral bands. Wide bandwidth links can exhibit angular dispersion, i.e., frequency-dependent radiation direction. While angular dispersion has enabled path discovery and dynamic beam steering via frequency tuning, multi-user communication in THz links remains an unaddressed challenge. This paper presents the first study and performance evaluation of multi-user THz WLANs with angularly dispersive links. We employ a single parallel-plate Leaky-Wave Antenna (LWA) for THz directional transmission and present a multi-user communication strategy that exploits angular dispersion and angular separation of users and provides all-spectrum access to users located in different directions with the objective of aggregate rate maximization. With analytical model-driven evaluations and over-the-air experiments that inform our trace-driven emulation of multi-user conditions, we show how the multi-user performance of an angularly dispersive LWA link fundamentally depends on frequency, angle, and bandwidth utilized by users through non-linear mechanisms. As increasing bandwidth yields a larger signal footprint in LWA links, we demonstrate that as compared to the model prediction, not only is the aggregate data rate maximized with wider beams, but the experimental link is far better even for practical irregular beams with side lobes and asymmetry. Our experimental findings reveal the potential of leveraging angular dispersion and users’ angular separation to establish a scalable THz wireless link that offers contention-free or medium access control-free access. Our results demonstrate the feasibility of accommodating up to 11 simultaneous users, making it a promising candidate solution for densely populated user environments.