Energy-Efficient Terahertz Communication for Sustainable 6G Networks

Abstract

The evolution of wireless systems toward sixth-generation (6G) networks demands data rates in the order of terabits per second, sub-millisecond latency, and massive device connectivity that existing millimeter-wave (mmWave) infrastructure cannot fully support. Terahertz (THz) communication, spanning the 0.1–10 THz band, has emerged as a promising enabler of this vision because of its enormous available bandwidth. However, the practical deployment of THz networks is constrained by severe propagation losses, high molecular absorption, and the substantial power consumption of THz-band hardware components such as power amplifiers, mixers, and high-resolution data converters, raising serious concerns for the energy sustainability of future networks. This paper presents a comprehensive investigation into energy-efficient THz communication for sustainable 6G networks. We first characterize the propagation and hardware-level factors that govern THz energy consumption, and then propose an integrated energy-efficient framework combining hybrid analog-digital beamforming, intelligent reflecting surfaces (IRS), artificial intelligence (AI)-driven adaptive resource allocation, and renewable energy-aware base station sleep scheduling. A system-level energy efficiency model is formulated, and simulation studies are carried out to evaluate the proposed framework against conventional fully-digital THz architectures. Results show that the proposed scheme achieves up to 58% improvement in energy efficiency (bits/Joule/Hz) at moderate transmit power levels and demonstrates favourable scaling with increasing IRS array size. The findings offer practical design guidance for building THz-enabled 6G infrastructure that balances ultra-high throughput with the sustainability goals of next-generation wireless networks.