A Novel Network Architecture and MAC Protocol for Confirmed Traffic in LoRaWAN

This paper presents a novel network architecture called edge acknowledging and a MAC protocol to enhance the reliability of LoRaWAN confirmed messaging. The edge acknowledging exploits the great capability of the gateway and high reliability of the cable-based connection between the gateway and net server to reduce the vulnerable period of the confirmed messaging. The new MAC protocol is time-slotted and constrains the end nodes from the contention for the channel to reduce the energy consumption. The performance of the combination of edge acknowledging and the new MAC protocol is evaluated in simulations and analysis using the metrics of packet reception ratio, end-to-end delivery probability, energy consumption per packet, and delay. The results show that our edge acknowledging architecture and the cooperating new MAC protocol obtain 4 to 10 times packet reception ratio, 2.5 times end-to-end delivery probability, and 97% lower energy consumption of the combination of the conventional LoRaWAN architecture and CSMA-like protocols for confirmed messaging. While the delay of our new solution for a successfully confirmed transmission increases by a factor of 20 to 30 in the large-scale network consisting of 500 nodes.