Apparatus and method to provide multicast/broadcast service in a mobile communication system

PURPOSE: A multicast/broadcast service providing device in the mobile communication system and a method are provided to provide a multicast/broadcast service by converting multicast data packet into alternation multicast data packet. CONSTITUTION: UE detects a data packet(611). UE compares the data packet with a multicast data packet(613). UE generates uplink-replacing multicast data packet(615). UE transmits a generated uplink-replacing multicast data packet to a femto Node B(617). UE compares data packet with a broadcast data packet(619). UE performs a unicast data packet transmission operation(621). UE generates an uplink-replacing broadcast data packet(623). UE transmits a generated uplink-replacing broadcast data packet to a femto Node B(625). [Reference numerals] (611) Detecting a data packet; (613) Multicast data packet?; (615) Generating an uplink-replacing multicast data packet; (617) Transmitting the uplink-replacing multicast data packet; (619) Broadcast data packet?; (621) Performing a corresponding operation; (623) Generating an uplink-replacing broadcast data packet; (625) Transmitting the uplink-replacing broadcast data packet; (AA,BB) No; (CC,DD) Yes