Flooding in LoRa Mesh Networks

Although LoRa is most well-known for the substantial distances over which it can transmit, it also has some characteristics that make it attractive as a mesh networking technology. In particular, it overcomes one of the main objections to using flooding as a routing mechanism in mesh networking. Flooding involves each node in the network forwarding a copy of every message it receives. Flooding is robust and simple, but unfortunately, if multiple nodes in the mesh receive a message, it typically results in many copies of the same message being received at the destination. However, a LoRa receiver synchronizes with only one transmitter and treats other messages as noise. Because duplicate messages are ignored, flooding can be designed to be much less wasteful of radio resources than mesh networks based on other wireless technologies. In this paper, we demonstrate that LoRa's physical layer mechanism ensures that only one copy of a message is forwarded by a node, regardless of how many copies it receives. We then present results from a simple LoRa mesh network to demonstrate that, for LoRa nodes, flooding is an efficient method of routing.

I. Introduction

LoRa (Long Range), a low-power, wide-area network (LP-WAN) technology, has emerged as a highly effective solution for IoT applications that demand extensive coverage with minimal power consumption [1]. Operating in unlicensed ISM bands, LoRa is particularly well-suited for sensor and actuator networks due to its low cost, ease of deployment, and impressive Communication range. In optimal conditions, LoRa can achieve communication distances of several kilometres using simple monopole antennas, with even greater ranges possible using directional antennas [2], [3]. This makes LoRa a good choice for a variety of applications, including smart cities, environmental monitoring, and industrial automation.