What Is a Femto Base Station?
Home basestations provide in-home mobility with maximum user data rates, but without loading the macro node-B cellsites. They are classified as "femto" power.
+45dBm—macro basestation covers outdoor cellsite ~5km
+30dBm—pico basestation covers campus ~0.5km
+15dBm—femto basestation covers indoor residence 50m
Femto basestation network access is through the publicly-switched telephone network, which is typically available through a residential DSL line. The handset only communicates to the femto station in the home, which completely offloads that user from the macrocell.
App Note 5331: Employing a Single-Chip Transceiver in Femtocell Base-Station Applications