I use only a basic fone due to me age...
I have no idea what mifi means, but my house has no landline so I use a radio system which I access via eth0 router and it suits me fine. There is also the Motorola Canopy system available in some areas, which gives more bandwidth and no contention issues. Same eth0 router access.
I live on the Costa Blanca, about 400km South of Catalonia.
Haakin lives in Lleida, which is Catalonia, so he may be better placed to advise, if he reads this.