Patent ID: 7039410

Claim:
A method at a mobile terminal, the mobile terminal being operative at a first carrier frequency with a base station in an area that overlays an underlay area comprising one or more base stations operating at an adjacent carrier frequency, the base station in the overlay area being in a first system that is operative in accordance with a first standard and the base stations in the underlay area being in a second system that is operative in accordance with a second standard different from the first, the method comprising: switching the mobile terminal from operation in accordance with the first standard at the first carrier to operation in accordance with the second standard at the adjacent carrier and redirecting it to a base station in the underlay area if both (1) the sum of measured power of a downlink signal received from the base station in the underlay area at the adjacent carrier plus, if it is transmitting, a present transmit power of an uplink signal being transmitted by the mobile terminal at the first carrier to the base station in the overlay area, is greater than a first predetermined threshold that indicates that the power received by the base station in the underlay area from the mobile terminal when the mobile terminal is transmitting an uplink signal at the first carrier can interfere with operation of a reverse link of that base station in the underlay area, and (2) if the difference between the measured power of the downlink signal received from the base station in the underlay area at the adjacent carrier and a measured power of a downlink signal received from the base station in the overlay area with which the mobile terminal is communicating at the first carrier is greater than a second predetermined threshold that indicates that the mobile terminal is near the border of the overlay area.