Method for transmitting packet data

A packet data transmission method is provided to trigger and transmit information requesting additional radio resources in transmitting an RTP(Real-time Transport Protocol) packet and an RTCP(RTP Control Protocol) packet. Radio resources with respect to the first packet with the first size are allocated through static scheduling information from a base station. A radio resource request message for requesting radio resources with respect to the second packet with the second size different from the first size is transmitted. The second packet data is transmitted. The radio resource request message is generated by a MAC(Medium Access Control) layer according to an instruction of an upper layer. The upper layer includes a packet type identifier in a header of the second packet, and the MAC layer generates the radio resource request message through the packet type identifier.