Patent ID: 7505475

Claim:
A multiple access communications system comprising: a master station; and a plurality of slave stations, each of which is connected to the master station using a multiple access controlled uplink and a broadcasting downlink and is connected to at least one terminal, wherein each of the slave stations transmits an uplink data packet and an uplink control information packet to the master station as an uplink transmission data packet, wherein each of the slave stations comprise: a first buffer for storing uplink transmission data packets; a second buffer for storing uplink transmission data packet status information indicating a status of each of the uplink transmission data packets; and a buffer controller controlling such that, when an uplink transmission data packet is stored in the first buffer, a control flag is set to not-changeable and is added to uplink transmission data packet status information corresponding to the uplink transmission data packet, and the uplink transmission data packet status information with the control flag set to not-changeable is stored in the second buffer.