Beyond the Star of Stars: An Introduction to Multihop and Mesh for LoRa and LoRaWAN

LoRa has emerged in recent years as a wireless technology providing long-range communication for low-power Internet-of-Things (IoT) devices. The LoRaWAN architecture adds the medium access control (MAC) and application layers, and defines a star of stars topology suitable for many and diverse IoT applications. However, in a number of scenarios, a more flexible network topology than LoRaWAN’s is needed. We review the state of the art of the design and implementation of multihop and mesh solutions for LoRa and LoRaWAN. We discuss the remaining challenges for multihop and mesh solutions to overcome in order to unlock the opportunities that decentralized, self-organizing, and infrastructure-less LoRa networks can bring to IoT applications.