Data transmission method for mobile communication system and controlling method for mobile communication terminal

The present invention relates to a method of controlling a mobile communication system, a data transmission method and a mobile communication terminal according thereto, the control method of the mobile communication terminal is, from a mobile communication system providing a CBS (Cell Broadcast Short Message) Service, Further comprising: configuring a mapping table of a CTCH BS (Block Set) and SFN (System Frame Number) by using an allocation period and CBS frame offset of the logical channel CTCH included in the SIB, and; Identifying a CTCH BS that a CBS message exists through the new message and the bit map; A (System Frame Number) SFN of CTCH BS that is the CBS message being and identifying in the mapping table; According to (System Frame Number) synchronization SFN at which the CBS message exists, it characterized in that it comprises a step of activating the receive function of the CBS message. In a way, that the mobile terminal can immediately calculate the SFN to check his CBS message in the process of the level 1 for calculating the DRX via the SIB, the power by turning on the receiver only for his CBS message receiving cycle It can save.