Redundancy systems for the teller

[Varunram]

A common occurrence we've observed from the Jan '20 pilot in Puerto Rico is the interruption of Internet connectivity on the lumen. Since the teller reads data from openx's mqtt broker, it will not be able to communicate data in the event connectivity is lost.

We need to find a solution by which the lumen device can directly communicate with the teller in the event the lumen (and the teller) can't interact with the remote broker. This may involve MQTT, or offline forms of communication like Radio Signals. This requires and understanding of the Lumen unit to arrive at a conclusion on what the best approach would be.