Method and device for fast connection and maintenance of millimeter wave system

In one aspect of the invention, a method, a computer readable medium, and an apparatus are provided. The apparatus may be a UE. The UE receives, on a primary cell (PCell), an indication indicating that a primary-secondary cell group (SCG) cell (PSCell) is added. And the UE initiates execution of the random access process on the PSCell. When the random access process is executed, the UE receives one or more reference signals in the PSCell; and the UE measuring one or more reference signals to select an antenna panel and a beam to receive data in the PSCell; the UE receives data in the beam at the antenna panel after completing the random access procedure. The method and the device have the beneficial effects that the MMW system is quickly connected, the connection of the MMW system is maintained, and the user experience is improved. 在本发明的一个方面，提供了一种方法、计算机可读介质和装置。该装置可以是UE。UE在主小区(PCell)上接收指示添加主辅小区组(SCG)小区(PSCell)的指示。UE发起对PSCell执行随机接入进程。在执行随机接入进程时，UE在PSCell中接收一个或多个参考信号；以及UE测量一个或多个参考信号以选择天线面板和波束以在PSCell中接收数据；UE在完成随