Microwave and fibre optics have altogether different applications.
Microwave is mostly used where we have terrain problems for the Fibre layout.
The mantainance cost of Microwave is much less as compareable to Fibre.
The overall cost per E1/Km of Fibre is much expensive than the microwave.
The outage time in case of Fibre breakage is much more as compare to microwave.
Optical fibre is more prone to natural calamaties than the microwave
In telephones the instrument has dedicated lines connected till the exchange whereas Mobile sends periodic information.
We need much more technical answers to testify.
Why do mobile phones dont have dial tones?