The mate 3 is powered by 24V, the AirGateway is also powered by 24 Volts. The mate3 does not have built in wifi – but it should for galvanic isolation reasons, this can save your power or internet equipment in a lightning strike.
Blue pairs = positive
Brown pairs = negative
Orange = negative
Orange White = positive
Blue Pairs = Orange White
Brown Pairs = Orange
Set as client mode to connect to your preferred WiFi network, set network mode to bridge.
The below picture is wrong – power should not be sent into the ethernet port of the MATE3 as it will start smoking.