PPPoE connection without the BT device w Fibre 2

[Rozgi]

I have had some networking issues so that I had to install an Aruba Instant wifi - mesh networking system. (Seems to work quite well.) 

I found that it is able to handle PPPoE connection as uplink and act as a firewall & router (besides access point and networking).

I am having a BT FTTC so I am getting the signal on a twisted pair. Do you think I can use my Aruba device to handle this connection via its PPPoE uplink port? 
Also, the device has a 4G modem that it can use as a parallel or backup uplink connection.  Does BT provide an affordably priced sim card that I can use for this purpose? 
THX

[West]

Look at the Hybrid offer which is a 4G unit.

The prices I have seen quoted would be cheaper than a SIM  

[Gary_C · Accepted solution]

FTTC = VDSL signal, so you need a device to convert that to a WAN ethernet connection for your PPPoE connection as I doubt the Aruba can do that bit.

Obviously the Smart Hub can do it all in one, but if you want to continue to use the Aruba unit, A Draytek Vigor 130 would be able to do the modem bit quite effectively (or even an old openreach VDSL modem)