If you want to prototype or test your solution with Telit's IoT Platform, then
you can use MIMIC MQTT Simulator to simulate a large number of sensors
In our initial effort we simulate a single sensor generating programmatic,
customizable, predictable, reproducible telemetry to Telit. With MIMIC what
can be done with one sensor can easily be scaled to thousands or even
millions of sensors. Complex scenarios can be setup once, and reproduced
at will thereafter. You can investigate different choices very quickly.
In the screenshot below, the light value changes randomly, but the
temperature value is changed predictably on-demand at run-time.