Abstract: A communication system, a data transmission method and a base station thereof are provided. The communication system includes a first base station and a second base station. The first base station includes a physical layer unit, a MAC layer unit and a PDCP layer unit. The physical layer unit is configured to transmit with a user equipment through a transmission channel. The MAC layer unit is configured to determine whether a retransmission ratio of the transmission channel is higher than a first threshold and to determine whether a transmission speed of the transmission channel is lower than a second threshold. If the retransmission ratio is higher than the first threshold and/or the transmission speed is lower than the second threshold, the first base station copy a packet and then transmits the copied packet to the second base station which accordingly transmits the copied packet to the user equipment.

Abstract: A communication system, a data transmission method and a base station thereof are provided. The communication system includes a first base station and a second base station. The first base station includes a physical layer unit, a MAC layer unit and a PDCP layer unit. The physical layer unit is configured to transmit with a user equipment through a transmission channel. The MAC layer unit is configured to determine whether a retransmission ratio of the transmission channel is higher than a first threshold and to determine whether a transmission speed of the transmission channel is lower than a second threshold. If the retransmission ratio is higher than the first threshold and/or the transmission speed is lower than the second threshold, the first base station copy a packet and then transmits the copied packet to the second base station which accordingly transmits the copied packet to the user equipment.