Patent ID: 7315525

Claim:
A method, comprising: measuring strength of a signal received by a mobile station on a first frequency band, sending information concerning a measured signal strength to a fixed network, comparing the measured signal strength on the first frequency band with a predetermined threshold value of the first frequency band, and changing the first frequency band to a second frequency band when necessary, as a result of the change, measuring strength of a signal received by the mobile station on the second frequency band, sending information concerning a measured signal strength of the signal received by the mobile station on the second frequency band to the fixed network, comparing signal strength measured on the second frequency band with a predetermined threshold value of the second frequency band, and changing the second frequency band back to the first frequency band, when insufficient, wherein, as a result of the above change back to the first frequency band, the threshold value of the first frequency band is changed, and the changed threshold value is then used for comparison with measured signal strength of the first frequency band.