White Paper — How to Deploy a LoRa®-based Network for your IoT Application Page 10 of 11
and the handling of payloads from many sensor nodes, its higher performance is suited
for this workload.
The distance between any given sensor node and its gateway should be no more than 2
km; however, this distance could increase or decrease depending on the specific
environmental factors present between gateway and sensor node. A clearer line of sight
allows the gateway and sensor node to be further apart more reliably.
An alternative to the WiFi uplink to the internet is a cellular uplink. This option has already
been tested with the Dots on a Map solution using a Digi Xbee3 Cellular LTE-M module.
In this case, after the Xbee3 is registered on the cellular network, it establishes the
secure MQTT connection with the Sandbox MQTT broker. Following that, the Xbee3
listens for payloads from the RX65N Gateway MCU over UART. The RX65N was
accordingly changed to forward sensor node payloads over UART to the Xbee3 instead
of directly to the Cloud. All other aspects of the solution remain the same, making the
change from WiFi to cellular simple to implement and proving the versatility of the Dots
on a Map solution.
