An embodiment of the invention provides a method of receiving packets from a transmitting station at a receiving station in a mobile communication system. The packet receiving method includes receiving a radio resource including a data packet and a packet indicator related to the data packet, identifying the packet indicator, and processing the data packet according to the content of the packet indicator. Another embodiment of the invention provides a method of transmitting packets from a transmitting station to a receiving station in a mobile communication system. The packet transmitting method includes receiving a response signal of a first data packet from the receiving station, allocating a second data packet to a radio resource according to the response signal, allocating a packet indicator related to the second data packet to the radio resource, and transmitting the second data packet and the packet indicator to the receiving station.