I have a 4G/LTE "modem" (with a sim that is), giving WiFi and Ethernet (4 ports). I also have a PPPoE broadband (the latter rather slow and some times unstable) I have a 2012 Time Capsule, at the moment extended with an AirPort express. We don't really need the latter for extending, but it's connected to amp/speakers so we can play music that way. Anyway, since our 4G internet has an unlimited contract now, we would like to combine it all (without extra hardware if possible). This is not only to get faster speeds, but also for a more reliable internet (as both the broadband and 4G are often unstable or even not working for periods of time) Can I leave the Time Capsule as it is - set up as PPPoE to the broadband "modem" - and then connect the 4G "modem" to the Airport Express - and get internet from both (at the same time)? (so the Airport Express takes internet IN from either WiFi in, or via ethernet from the 4G "modem") Or is there another way to do it? We have contracts for both, so we might as well get some use out of them. Thank you for assisting.