I'm looking for reference information (for existing libraries) or implementation notes on how to utilize MQTT-SN over Zigbee using XBEE modules. Ideally using Micropython with XBee3 Zigbee RF Modules. The Zigbee based WPAN would be connecting to an existing TCP based MQTT infrastructure via an MQTT gateway. I'm just getting started on this aspect of the project and would rather not re-invent any wheels if there is information out there on the subject. I did some digging, but so far haven't come up with much beyond the specs.