System and its method for transmission group net in radio cut-in net

The present invention relates to a mobile communication system, there is disclosed a system and method for transmission within a radio access network of the network, such that both the low total cost of the transmission network between base stations and base station controllers can reliably meet service user , QoS, security requirements. In the present invention, the establishment of two transmission network between the base station controller and a base station, a QoS is guaranteed, and the other is non-guaranteed QoS. Using the QoS guaranteed transmission network transmitting the control signaling, voice and low-speed data services such as real-time QoS requirements of high data transmission using QoS non-guaranteed network transmitting non-real time high-speed data service with low QoS requirements of the data.