Patent ID: 8315199

Claim:
A method at a first user terminal in a satellite system, the satellite system including the first user terminal and a second user terminal that are secondary spectrum license holders, the method comprising: receiving an assignment of a first transmit frequency channel; transmitting satellite uplink signals during time-separated periods of transmission in the first assigned transmit frequency channel; monitoring the first assigned transmit frequency channel between the time-separated periods of transmission of satellite uplink signals using a first antenna, the monitoring to determine possible presence of an interfering terrestrial signal that is a primary spectrum license holder in the first assigned transmit frequency channel; monitoring a second assigned transmit frequency channel different from the first assigned transmit frequency channel using a second antenna, the monitoring to determine possible presence of an interfering terrestrial signal that is a primary spectrum license holder in the second assigned transmit frequency channel, wherein the second assigned transmit frequency channel is assigned to the second user terminal; generating a first observation result indicating the determination of presence of an interfering terrestrial signal in the first assigned transmit frequency channel and indicating the determination of lack of a presence of an interfering terrestrial signal in the second assigned transmit frequency channel; receiving an indication of a re-assignment from the first assigned transmit frequency channel to the second assigned transmit frequency channel in response to the first observation result and a second observation result generated by the second user terminal, the second observation result indicating the determination, by the second user terminal, of lack of a presence of an interfering terrestrial signal in the second assigned transmit frequency channel and indicating the determination, by the second user terminal, of lack of a presence of an interfering terrestrial signal in the first assigned transmit frequency channel; and transmitting second satellite uplink signals in the second assigned transmit frequency channel.