本文主要研究了LTE系统终端RRC子层的功能模型和RRC子层的状态，以及系统终端正常通信时RRC的连接建立过程。通过对RRC子层传统上划分的空闲和连接两个大的状态分别细分为3个子状态，以及定义了RRC到高层和到底层的原语，通过以上方法，系统描述了LTE系统终端正常通信过程中RRC连接建立过程，并结合流程图说明。

The paper mainly discusses the functional model and the state of RRC sublayer in LTE system，as well as the connection eatablishment process of RRC sublayer when it communicates with another user normally．Traditionally there are two large states which are idle and connection．Now，it divide them into three sub-state separately．In addition，it defines the RRC to the high-level and to the underlying primitives，by the above method，it can systematically describes the connection eatablishment process of normal communication of LTE system，combined flow chart to illustrate this process．