Abstract: Radios configured to operate in a satellite-based mobile user system and methods configured to support seamless beam and satellite handoff of such radios are disclosed. A radio may include a receiver, a transmitter, and one or more receiver-exciter in communication with the receiver and the transmitter. The receiver-exciter may include a bi-directional path configured to support radio communications and a receive-only path configured to receive signals on all frequencies utilized by a mobile user system. The radio may further include one or more waveform processor in communication with the receiver-exciter. The waveform processor may be configured to: digitize signals received on all frequencies utilized by the mobile user system; separate the signals into multiple channels; estimate quality measurements for the multiple channels; select a channel from the multiple channels based on the quality measurements; and establish a connection with the mobile user system using the selected channel.