Towards Standardization of MQTT-Alert-based Sensor Networks: Protocol Structures Formalization and Low-End Node Security

We present a small scale sensor network application as a testbench to explore different setups in terms of hardware/ software, network protocol and data processing/storage scheme options, focusing on alert-based sensor systems with long idle times. Our specifications required the deployment of the network using the MQTT protocol over an encrypted TLS connection. We focused on using sensor nodes with low-power consumption profile, as well as on the formalization of the MQTT protocol's basic elements, by clearly defining the topic/message scheme used across the network. In addition, we experimented on how to combine locally stored information with data from popular cloud-based platforms and also acquired results regarding the processing performance of the nodes using different data exchange formats and database technologies. Work in progress includes data preprocessing on the network edge targeting distribution of the processing power across the network and network-traffic limitation, and also big data post-processing on server side or on dedicated high performance nodes to reveal hidden data patterns.