MOBILE COMMUNICATION SYSTEM AND METHOD THEREFOR

PROBLEM TO BE SOLVED: To excellently enable a hand over even between the areas of different frequencies by switching the first frequency to the second frequency and performing data transmission and reception of a CDMA system at the time of executing radio cell search from the first radio cell to the second radio cell. SOLUTION: A mobile station M stays in a cell of frequency f2 , receives a peripheral cell diffusion code and stores it. Next, a reception quality is measured by a count up of a peripheral cell search timer and is given to a network. Subsequently, in a moving direction determination means 25, the moving direction is determined, and further in the same frequency outer circle determination means 26 moves outside the same frequency circle and it is determined whether a frequency changeover is necessary or not. Then, when the changeover is necessary, a mobile station M performs the frequency changeover with a frequency changeover means 14, performs the peripheral cell search and informs the network of it after a control station C gives a radio base station Ba an instruction of a transmission and reception set at a frequency f1 . The network instructs a soft handover from a f1 cell to a f2 cell by a handover control means 27.