Method for establishing a fronthaul interface, method for performing access for a ue, method and apparatus for performing a handover for a ue, data forwarding method, user equipment and base station

A central unit (CU) of a base station, the CU of the base station comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to:
• receive, from a source distributed unit (DU) of the base station, a first message including a measurement report, the measurement being received from a user equipment (UE),
• determine a target DU of the base station for a handover of the UE based on the measurement report,
• transmit, to the target DU of the base station, a second message for creating a UE context,
• receive, from the target DU of the base station, a third message in response to the second message, the third message including a cell-radio network temporary identifier (C-RNTI) allocated by the target DU for the UE context, and
• transmit, to the source DU of the base station, a fourth message including information indicating to stop data transmission for the UE.

A method by a source distributed unit (DU) of a base station, the method comprising:

• receiving, from a user equipment (UE), a measurement report;
• transmitting, to a central unit (CU) of the base station, a first message including the measurement report;
• receiving, from the CU of the base station, a second message including information indicating to stop data transmission for the UE;
• and
• transmitting, to the UE, a radio resource control (RRC) connection reconfiguration message.

A source distributed unit (DU) of a base station, the source DU of the base station comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to:
• receive, from a user equipment (UE), a measurement report,
• transmit, to a central unit (CU) of the base station, a first message including the measurement report,
• receive, from the CU of the base station, a second message including information indicating to stop data transmission for the UE, and
• transmit, to the UE, a radio resource control (RRC) connection reconfiguration message.

A method by a target distributed unit (DU) of a base station, the method comprising:

• receiving, from a central unit (CU) of the base station, a first message for creating a UE context;
• configuring at least one bearer for the UE based on the first message;
• transmitting, to the CU of the base station, a second message in response to the second message, the second message including a cell-radio network temporary identifier (C-RNTI) allocated by the target DU for the UE context;
• receiving, from the UE of the base station, a radio resource control (RRC) connection complete message;
• and
• transmitting, to the CU of the base station, a third message including the RRC connection complete message.

A target distributed unit (DU) of a base station, the target DU of the base station comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to:
• receive, from a central unit (CU) of the base station, a first message for creating a UE context,
• configure at least one bearer for the UE based on the first message,
• transmit, to the CU of the base station, a second message in response to the second message, the second message including a cell-radio network temporary identifier (C-RNTI) allocated by the target DU for the UE context,
• receive, from the UE of the base station, a radio resource control (RRC) connection complete message, and
• transmit, to the CU of the base station, a third message including the RRC connection complete message.