MoRa: A LoRaBased System for Timely and EnergyEfficient ePrice Tag Update in Markets While numerous wireless applications are emerging to simplify our daily life, updating price tags in largescale markets is still largely performed manually. Considering the potential adoption of electronic price (eprice) tags, we propose MoRa, a LoRabased system for timely and energyefficient price update in Markets. By leveraging the category information in the market, we design a hierarchical address scheme. Based on the scheme, we can perform efficient multicast with nearly zero overhead in group joining and activity scheduling. Furthermore, considering LoRau0027s characteristics and the asymmetry between the gateway and nodes, we let the gateway make fast and repetitive transmissions before the uncovered nodes send light weight NAKs. Extensive testbed experiments and simulation evaluations are conducted. Results demonstrate that MoRa can efficiently improve the performance in terms of update delay and energy consumption.

Fast and Reliable LoRabased Data Transmissions LoRaWAN is a recently proposed MAC layer protocol which manages communications between LoRabased gateways and enddevices. It has attracted much scientific attention due its physical layer characteristics, but mainly due to its versatile configuration parameters. However, it is known that LoRaWANbased transmissions suffer from extensive collisions due to the unregulated access to the medium. For this reason, various techniques that alleviate the burst of collisions have been proposed in the literature. In this paper, we deal with the problem of fast data delivery in LoRabased networks. We model a network where transmissions follow a Poisson process. We compute the average packet success probability per Spreading Factor (SF) assuming orthogonal transmissions. We, then, formulate an SF optimization problem to maximize the success probability given an amount of data per node and a maximum data collection time window. We show xe2x80x93 both theoretically and using simulations xe2x80x93 that the overall success probability can be improved by approximately 100% using optimal SF assignments. We validate our findings using a 10node testbed and extensive experiments. Despite that experiments reveal the existence of interSF interference, our solution still provides the best performance compared to other LoRaWAN configurations.