A method for paging user equipments (UEs) receiving a second service in a
mobile communication system providing a first service and the second
service. A serving General Packet Radio Service (GPRS) support node
(SGSN), determines an identifier indicating the second service and a
coefficient related to paging occasions for transmitting a paging
instance indicating presence/absence of paging information related to the
second service in response to a request for the second service from UEs,
and transmits the determined identifier and coefficient to a radio
network controller (RNC). The RNC transmits the identifier and the
coefficient to the UEs, determines the paging occasions and transmission
times of the paging instance in each of the paging occasions by using the
identifier and the coefficient, and transmits the paging instances over a
first channel at the transmission times of the paging instances for each
of the paging occasions so that the UEs recognize presence/absence of the
paging information.