The invention relates to a method for operating a moblile terminal and mobile terminal. The mobile terminal runns in a mobile station in a wireless network system comprising a plurality of base stations allocated in N channels. Data packets are received at a time interval p from a first base station of the wireless network system to which the mobile station is currently connected. A first period T is provided for a complete background scan monitoring messages from the plurality of base stations located in the wireless network system. The complete background scan is divided into a plurality ofpartial scan sections, each of which monitors base stations of one of the N channels. A second period M is determined for the partial scan section according to the time interval p, the first period T, and the number of channels N. The said method and the background scan mechanism can reduce the mutual interference between the background scan and the other delivery operations and the delivery performance is increased.