Spreading Factor Allocation for Extension of End Device Lifetime in LoRaWAN

In this study, we investigate a spreading factor allocation method for extending the end device (ED) lifetime in LoRaWAN. Long range (LoRa) is a communication standard that has attracted attention because it can facilitate the construction of a local or private network. The authors have defined a constrained optimization problem for spreading factor allocation in LoRa Wanwith the average power consumption of EDs as the constraint, and have shown the solving method of the problem using a distributed genetic algorithm (GA). This study extends the approach by defining an optimization problem for power balancing by rotating the allocated spreading factor to reduce the increase in power consumption owing to the continuous use of high spreading factor by arbitrary EDs, and the solving method of the problem using a distributed GA is developed. The effectiveness of the studied method is demonstrated by computer experiments.