Next Generation LoRaWAN: Integrating Multi-Hop Communications at 2.4 GHz

TL;DR

This paper tackles the limitations of LoRaWAN in terms of coverage and data rates by proposing a hybrid network that jointly leverages sub-GHz LoRaWAN and the 2.4 GHz spectrum through multi-hop relay nodes. The approach preserves standard compatibility while introducing multi-band relay-enabled clusters that receive from 2.4 GHz endpoints and forward over sub-GHz links, with cluster-specific channels to minimize interference. Using an open-source, standards-compliant simulator, the authors demonstrate up to 97% throughput gains and up to 67% energy savings compared to single-band baselines, especially in larger deployments. The work highlights the potential of hybrid multi-band, multi-hop LPWANs to extend IoT capabilities, though it also notes the practical costs of deploying relay infrastructure and the need for further exploration of standardization and optimization in real-world settings.

Abstract

The Internet of Things (IoT) revolution demands scalable, energy-efficient communication protocols supporting widespread device deployments. The LoRa technology, coupled with the LoRaWAN protocol, has emerged as a leading Low Power Wide Area Network (LPWAN) solution, traditionally leveraging sub-GHz frequency bands for reliable long-range communication. However, these bands face constraints such as limited data rates and strict duty cycle regulations. Recent advancements have introduced the 2.4 GHz spectrum, offering superior data rates and unrestricted transmission opportunities at the cost of reduced coverage and severe interference. To solve this trade-off, this paper proposes a novel hybrid approach integrating multi-band (i.e., sub-GHz and 2.4 GHz) and multi-hop communication into LoRaWAN, while preserving compatibility with the existing standard. The proposed network architecture retains Gateways (GWs) and End Devices (EDs) operating within the sub-GHz frequency while introducing multi-band Relays (RLs) that act as forwarding nodes for 2.4 GHz EDs. Utilizing our previously developed open-source and standards-compliant simulation framework, we evaluate the network performance of our solution under realistic deployment scenarios. The results demonstrate substantial improvements compared to standard single-band and single-hop LoRaWAN networks, demonstrating the potential of this approach to redefine LPWAN capabilities and bridge the gap between current solutions and next-generation IoT applications.

Figures (5)

• Figure 1: Pictorial representation of a LoRaWAN network architecture.
• Figure 2: Exemplary representation of the proposed network architecture. (green circles) communicate with (yellow stars) using LoRaWAN at 2.4 GHz, forming clusters where each of them operates on a dedicated radio channel within this spectrum. transmit both their own data and that of their associated to a central (blue triangle) via LoRaWAN at EU868 MHz. Links can be in either or , depending on obstructions caused by buildings (gray squares).
• Figure 3: Network throughput as a function of the number of EDs, the number of RLs, and for the two benchmark cases. We set $A_{\rm L}=1$ km.
• Figure 4: Network throughput as a function of the number of EDs, the number of RLs, and for the two benchmark cases. We set $A_{\rm L}=5$ km.
• Figure 5: Network Throughput as a function of the number of RLs, and the number of EDs, with $A_{\rm L}=5$ km.