Abstract: Disclosed is a technique for switching from a master node to a secondary node in a communication system. A method of a first communication node may comprise: adding the first communication node as a primary secondary cell (PSCell) to a second communication node through dual connectivity (DC); generating a first user plane path for smart dynamic switching (SDS) and a first instance for supporting the first user plane path according to a request from the second communication node; transmitting information on the first user plane path and the first instance to a terminal; receiving user data based on the first user plane path from the terminal as the first instance; and transmitting the user data to a core network using the first user plane path.

Abstract: The present invention relates to a pop-up book for playing that allows various types of three-dimensional play, such as orally narrated fairy tales and dramas, by providing a three-dimensional stage standing and fixed when the pop-up book for juvenile play is opened, and can be easily kept by minimizing the thickness when it is closed. Accordingly, the pop-up book for playing of the invention, which has a front cover and a back cover pivoting around a pivot edge, and is closed in a plane when the front cover and the back cover are folded and provides a three-dimensional shape protruding in a space between the front cover and back cover when the front cover and the back cover are unfolded, includes a first stage that is unfolded to protrude from the back cover and a fixing means that fixes the first stage, the front cover, and the back cover to the unfolded positions.