4G LTE Modems
There are a multitude of LTE modems provided by ISPs. As these devices use the OPT port of the SimpleWAN unit, it may be ideal to use these as back up as well. Keep in mind that some, if not all, of these will need to remain Unbridged as they do not work otherwise.
The Simplewan device LAN range should be something other 192.168.1.1 for the failover to work. ex: 192.168.10.1 etc..