In a cellular system for packet service, a plurality of terminals share radio resources unlike a circuit system where resources are allocated only to one terminal.
Accordingly, notification of the fact that radio resources are allocated to each terminal in the cellular system is required to be performed through AC response information so that each terminal can discriminate and access to the radio resources. In this instance, the cellular system is required to possess and transmit using minimal radio resources, thereby maximizing application of limited radio resources, when transmitting RA response information. Also, the RA response information is required to have a format for improving operational efficiency of a terminal that receives the RA response information.