Energy efficient selection of spreading factor in LoRaWAN-based WBAN medical systems
Résumé
Recently, the Internet of Things has been leading the technological revolution in several fields
and applications. This revolution affected healthcare services adding more value to the concept
of e-health. To improve the quality of these services, remote monitoring allows healthcare
professionals to observe and diagnose their patients without being physically present. Since
the spreading factor affects the energy consumption, the data rate, the receiver sensitivity and
the time on air. A monitoring healthcare system using LoRa technology is proposed on this work
to adopt the data transmission in a reliable and energy-efficient way. We propose a method to
select the most convenient spreading factor based on the patients medical state. This method
takes in consideration the distance to gateway, the packet error rate and the energy consumption
requirements.
We first determine the criticality level of the patient using the Early Warning Score system.
Second, a decision about the optimal spreading factor is taken based on this level. We use a
method based on the technique for order preference by similarity to an ideal solution to select
a spreading factor. We use real data to show that the results reflect an acceptable increase in
energy consumption while applying our selection method. In contrast, the results show that the
selection method reduces the error rate especially for patients with a high critical level.