This patent discloses a method to communicate between a femtocell base station and mobile devices. The method may include identifying as an alert group a set of mobile devices presently in communication with the femtocell base station and whose unique identifiers are preregistered with the femtocell base station. A first mobile device and a second mobile device may be in the set of femtocell service region mobile devices. The femtocell base station may receive a call from a third mobile device. If the call is for the second mobile device, then the method may send a paging message from the femtocell base station. The paging message may include a first unique identifier associated with the first mobile device.