Wifi in the Omni is provided by TP-Link N750 routers that have been modified for PoE use.
We modified the TP-Link routers to accept PoE by soldering the PoE lines from the WAN ethernet ports to the DC input pins. This has the side effect of limiting the routers to 100 mbit ethernet. A better, but costlier solution, is to use unmodified TP-Link routers and run 48 VDC to a TP-Link PoE splitter that downregulates to 12 VDC.
The TP-Link N750 uses a MP1482DS voltage regulator which accepts between 4.75 and 18 VDC. We are currently injecting 12 VDC into the ethernet cables for the routers at our central server location. The voltage drop from there to the routers is probably fairly significant. For 200 feet on CAT6 it would drop to about 5.9 volts and we probably don't have any cable runs longer than that.