US Patent 10306699 User equipment and base station

Techniques are disclosed for implementing efficient transmission of uplink packets when the uplink transmission direction is changed in a split bearer. One aspect of the present invention relates to user equipment, comprising: a transmission and reception unit configured to communicate with a master base station and a secondary base station simultaneously in dual connectivity; an RLC (Radio Link Control) layer processing unit configured to have an RLC layer for the master base station and an RLC layer for the secondary base station; and a PDCP (Packet Data Convergence Protocol) layer processing unit configured to have a PDCP layer transmitting and receiving data to/from the RLC layer for the master base station and the RLC layer for the secondary base station, wherein when a transmission direction of uplink data packets is changed in the split bearer configured for the master base station and the secondary base station, the RLC layer processing unit performs re-establishment on the RLC layer for the master base station and the RLC layer for the secondary base station, and the PDCP layer processing unit performs re-establishment on the PDCP layer.