The present invention provides a radio access network system, comprising: a core network CN; a plurality of radio access gateways (RAGs) each performing processing of all the L1/L2/L3 protocols in a radio interface access layer; and a plurality of remote RF units (RRUs); wherein said plurality of RAGs are connected with said CN via Iu interfaces and are connected with each other via Iur or Iur+ interfaces, said plurality of RAGs are connected with corresponding RRUs via Iua interfaces for realizing the control of said plurality of RAGs over said corresponding RRUs and digital radio signal transmission therebetween. In a specific mode for carrying out the present invention, each of said RAGs is divided into two independent network elements, i.e., a radio bearer server RBS and a radio control server RCS. The above radio access network architecture set forth in the present invention overcomes the problems existing in the original UTRAN architecture, solves the frequent mobility management problem, and supports an architecture which has a clear configuration and an explicit function division and in which the user plane and the control plane of an RAN are separated.