You can check what is in your area but VFast
are in mine. They do wireless broadband in south east Kent (not sure where you are based).
Total waste of money for myself, but if I did have a need for two connections on physically different transport mediums (FTTC landline and wireless microwave), that would be a pretty sweet setup. But I cannot personally justify the price or need for it.
Anyway, you suggested ADSL2+ as a backup so are looking for two physical line solution, but thought I would suggest it anyway.
Edited by mixt (Tue 12-May-15 13:24:53)