Performance Analysis of Multi-Hop Networks at Terahertz Frequencies

TL;DR

This work tackles the limited coverage of Terahertz THz wireless links in Industrial IoT by proposing two fully distributed multi-hop routing schemes, Table-Less (TL) and Table-Based (TB), that avoid control-plane signaling. Through Unslotted Aloha-based MAC and THz-specific channel modeling, the paper demonstrates that both TL and TB can achieve several Gbit/s of network throughput with sub-microsecond latency in a realistic plant scenario, under both static and dynamic conditions. TB generally outperforms TL in static settings due to lower overhead from unicast forwarding, while TL shows greater robustness to topology changes thanks to its broadcast-forwarding mechanism. These results underscore the practicality of simple, distributed THz multi-hop protocols for demanding IIoT applications and point to future work incorporating AI to optimize the trade-offs between the two approaches.

Abstract

The emergence of THz (Terahertz) frequency wireless networks holds great potential for advancing various high-demand services, including Industrial Internet of Things (IIoT) applications. These use cases benefit significantly from the ultra-high data rates, low latency, and high spatial resolution offered by THz frequencies. However, a primary well-known challenge of THz networks is their limited coverage range due to high path loss and vulnerability to obstructions. This paper addresses this limitation by proposing two novel multi-hop protocols, Table-Less (TL) and Table-Based (TB), respectively, both avoiding centralized control and/or control plane transmissions. Indeed, both solutions are distributed, simple, and rapidly adaptable to network changes. Simulation results demonstrate the effectiveness of our approaches, as well as revealing interesting trade-offs between TL and TB routing protocols, both in a real IIoT THz network and under static and dynamic conditions.

Figures (6)

• Figure 1: The considered scenario.
• Figure 2: 2D map illustrating the uplink $SNR$ distribution in the considered industrial plant.
• Figure 3: Flowchart of the layer protocol from the side.
• Figure 4: Network Throughput, $S$, as a function of the number of , $N$, and the four simulation cases.
• Figure 5: Average latency, $\overline{L}$, as a function of the number of , $N$, and the four simulation cases.