Enhancing LoRaWAN-based Connectivity for Scalable Smart City Applications

IoT connectivity is a crucial enabler for Smart City applications. Given the plethora of applications each with its own distinct requirements, a variety of connectivity solutions have emerged that cater to this wide spectrum of needs from short-range to long-range, low data rate to high data rate, and the ability to scale up with an increasing network size. Low Power Wide Area Networks (LPWANs) offer a niche in this segment providing long-range, low data rate, and low-cost access suitable for a range of applications. LoRaWAN, one of the technologies under this umbrella, has been one of the front runners in this space. The ready availability of hardware in the market combined with an open specification has led to widespread interest in this technology with network deployments emerging not only from hobbyists but also some of the operators. In this paper, we highlight some opportunities for enhancing the performance and scalability of LoRaWAN-based IoT networks. Towards the same, we first highlight the shortcomings of one of the ACK transmission approaches and propose a remedial solution. Findings show the promise of the proposed solution in improving performance and scalability as the network scales up with a vast majority of the packets being delivered in the first attempt itself (50-100% more in comparison to the default approach) which leads to lower retransmissions and better goodput. We also highlight the practical deployment considerations. These findings would be of interest to stakeholders planning to deploy IoT connectivity for supporting scalable smart city applications using this technology.