What is the difference between women praying in a two-story mosque where there is no connection between the floors except by sound, and praying behind a radio, which the scholars have not permitted?

It is permissible for women to follow the imam by hearing his voice through a microphone if they are within the mosque building. However, following the imam via radio is not permissible due to the absence of the true meaning of congregational prayer. The exclusion of women from the upper floor, when necessary, is justified by the fact that congregational prayer for men is obligatory or a confirmed Sunnah (definition), whereas for women it is merely permissible, and their prayers in their homes are better.