Terminal device, base station apparatus, communication system, communication control method, and integrated circuit

A communication control method for a terminal apparatus configured to be configured with a first cell group and a second cell group, the first cell group containing cells of a first base station apparatus, and the second cell group containing cells of a second base station apparatus, the communication control method comprising;

• first base station apparatus, a first list of data radio bearers including a first identifier of data radio bearers, a PDCP configuration (packet data convergence protocol), a first RLC (radio link control) configuration and a second RLC configuration;
• and
• establishing a PDCP, a first RLC, and a second RLC, wherein
• the terminal apparatus communicates with the first base station apparatus and the second base station apparatus using the first RLC, the second RLC, and the PDCP, the first RLC corresponding to a first cell group including at least the primary cell, the second RLC corresponding to a second cell group not including the primary cell, and the PDCP being configured to process first data of the first RLC and second data of the second RLC,
• in a case that receiving, from the base station apparatus, a second list of data radio bearers including a second identifier of data radio bearers being used for both the first cell group and the second cell group,
• releasing the second RLC corresponding to the second identifier included in the second list.

A base station apparatus configured to establish a connection with a terminal apparatus using a plurality of serving cells including a primary cell, the base station apparatus comprising;

• control circuitry configured and/or programmed to establish a PDCP (packet data convergence protocol), a first RLC (radio link control), and a second RLC, and configured and/or programmed to transmit, to the terminal apparatus, a first list of data radio bearers including a first identifier of data radio bearers, a PDCP configuration, a first RLC configuration and a second RLC configuration;
• wherein,
• in a case that the base station apparatus communicates with the terminal apparatus using the first RLC, the second RLC, and the PDCP, the first RLC corresponding to a first cell group including at least the primary cell, the second RLC corresponding to a second cell group not including the primary cell, and the PDCP being configured to process first data of the first RLC and second data of the second RLC,
• the control circuitry is configured and/or programmed to generate a second list of data radio bearers including a second identifier of data radio bearers being used for both the first cell group and the second cell group, and
• the transmission circuitry is configured and/or programmed to transmit, to the terminal apparatus, the second list to release the second RLC corresponding to the second identifier included in the second list.

A communication control method for a base station apparatus configured to establish a connection with a terminal apparatus using a plurality of serving cells including a primary cell, the communication control method comprising;

• establishing a PDCP (packet data convergence protocol), a first RLC (radio link control) and a second RLC;
• and
• transmitting, to the terminal apparatus, a first list of data radio bearers including a first identifier of data radio bearers, a PDCP configuration, a first RLC configuration and a second RLC configuration;
• wherein
• the base station apparatus communicates with the terminal apparatus using the first RLC, the second RLC, and the PDCP, the first RLC corresponding to a first cell group including at least the primary cell, the second RLC corresponding to a second cell group not including the primary cell, and the PDCP being configured to process first data of the first RLC and second data of the second RLC,
• generating a second list of data radio bearers including a second identifier of data radio bearers being used for both the first cell group and the second cell group, and
• transmitting, to the terminal apparatus, a second list to release the second RLC corresponding to the second identifier included in the second list.