I had been asked this question by my college professor while I was bunking the class.
Asked question is from Femtocell Network topic in portion Satellite Systems & Recent Advances of Wireless/Mobile
To explain: The “femto” means 10-15. Coverage of Femtocell Network is much smaller than a regular Macro cell Network that is why this name is given. Femtocell Network, installed by end users at home or in an office environment.