In some extraordinary situations like natural disasters or terrorist attacks, cellular mobile networks may face dramatically increased network traffics. Due to GSM network architecture, the number of available radio traffic channels within a cell is limited and this limitation may cause traffic congestions on such conditions. These congestions may drop the quality of mobile subscriber service channels. With our study a new experimental approach method for congestion relief for extra ordinary situations is proposed which is tested at a GSM operator network to keep the quality of network sustainable and at maximum efficiency. Basic concept of offered solution approach is to use limited number of radio network channels more effectively at the time of extraordinary situations.