Design and Implementation of Multihop Real-Time Lora Protocol

Abstract

Recently, LoRa (Long Range) technology has been attracting attention in industrial monitoring applications due to its long communication distance and high link reliability. This dissertation aims at designing a new multi-hop LoRa protocol to provide real-time and reliable data transmission as well as cover a sufficient large area in industrial applications. The protocol constructs and maintains a two-hop tree topology to extend the network coverage to wireless unfriendly zones such as underground tunnels, enclosed spaces, and harsh construction houses with steel or concrete obstructions. Then, based on the two-hop network topology, a TDMA-based real-time slot schedule is applied to remove data collision as well as guarantee the time constraint of every data transmission. Furthermore, the proposed protocol also addresses technical aspects of dynamic networks such as the auto-configuration of multi-hop LoRa networks, dynamic topology management, and updating of slot schedules. The protocol was evaluated through analysis, simulation, and various real site experiment scenarios. It can be seen by analysis that the proposed protocol can support a densely deployed network of hundreds to thousands of nodes. Furthermore, the simulation and experiment results show that the protocol could achieve high reliability on data transmission as well as generate low maintaining overhead against the node mobility.