Cross-layer Analysis of Optimal Relaying Strategies for Terahertz-band Communication Networks

Terahertz (THz) band (0.1-10 THz) communication, which is envisioned as one of the key wireless communication technologies of the next decade, exhibits an extremely large bandwidth at the cost of an extremely high path loss. The unique distance-dependent behavior on the available bandwidth in THz communication interrelates all THz properties, and affects the design and performances within and across the physical, link and network layers. More specifically, the limited transmission power, combined with the high path loss, requires the use of directional antennas (DAs). High DAs have a clear impact at the link layer as well as the network layer, where relaying becomes a requirement. In this paper, optimal relaying strategies for THz-band communication networks are investigated. More specifically, a mathematical framework is formulated and used to study the optimal relaying distance that maximizes the network throughput by taking into account the cross-layer effects between the channel, the antenna, and the physical, link and network layers. Numerical results are provided to illustrate the importance of accurate cross-layer design strategies for THz networks.