Experimental Analysis of the Over-The-Air Activation procedure in LoRaWAN

Long Range Wide Area Network (LoRaWAN) technology is knowing an impressive growth. It is considered by many researchers as the new era of Internet of Things (IoT) communication. Several studies focus on evaluating the LoRaWAN performance according to many features such as coverage, scalability, and communication reliability. However, these studies assume that LoRaWAN end-devices are already activated by the network server. Thus, the performance of LoRaWAN activation procedure, referred as Over-The-Air Activation (OTAA), is not widely treated.In this paper, we elaborate an experimental analysis of the OTAA procedure performance using a real field LoRaWAN deployment. Our objective is to analyse the end-device activation delay and power consumption at large scale LoRaWAN. To achieve this goal, we design an experimental scenario of 30 end-devices competing for being activated by sending network join-requests. Upon its activation, each end-device transmits unconfirmed data at high rate, which simulates a large-scale LoRaWAN where hundreds of end-devices send their join-requests concurrently. Results show that OTAA procedure incurs high activation delays and power consumption, especially in large scale where the network traffic is high. This is due to three main factors: collisions, the back-off retransmission mechanism and join-request duty-cycle.