Method and eNB equipment for supporting seamless handover

A method performed by a target secondary base station in a communication system, the method comprising:

• receiving, from a master base station, a secondary base station addition request message, the secondary base station addition request message including information associated with an enhanced handover indication;
• and
• transmitting, to the master base station, a secondary base station addition acknowledge message including a radio resource control (RRC) container, the RRC container including the enhanced handover indication,
• wherein the secondary base station addition request message includes the information associated with the enhanced handover indication based on information indicating a user equipment (UE) supports an enhanced handover process included in UE capability information, and
• wherein the enhanced handover process is a handover where a connection between a source secondary base station and the UE is maintained after transmission of an RRC reconfiguration message before a random access channel (RACH) access from the UE to the target secondary base station is performed.

A method performed by a user equipment (UE) in a communication system, the method comprising:

• transmitting, to a master base station, UE capability information including information indicating the UE supports an enhanced handover process;
• receiving, from the master base station, a radio resource control (RRC) reconfiguration message including an RRC container, the RRC container including an enhanced handover indication;
• and
• performing a synchronization to a target secondary base station after the UE receives the RRC reconfiguration message,
• wherein the enhanced handover process is a handover where a connection between the UE and a source secondary base station is maintained after a reception of the RRC reconfiguration message before the UE performs a random access channel (RACH) to the target secondary base station.

A master base station in a communication system, the master base station comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to:
• receive, from a user equipment (UE), UE capability information including information indicating that the UE supports an enhanced handover process,
• transmit, to a target secondary base station, a secondary base station addition request message, the secondary base station addition request message including information associated with an enhanced handover indication,
• receive, from the target secondary base station, a secondary base station addition acknowledge message including a radio resource control (RRC) container, the RRC container including enhanced handover indication, and
• transmit, to the UE, an RRC reconfiguration message including the RRC container,
• wherein the enhanced handover process is a handover where a connection between a source secondary base station and the UE is maintained after the transmission of the RRC reconfiguration message before a random access channel (RACH) access from the UE to the target secondary base station is performed.

A target secondary base station in a communication system, the target secondary base station comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to:
• receive, from a master base station, a secondary base station addition request message, the secondary base station addition request message including information associated with an enhanced handover indication, and
• transmit, to the master base station, a secondary base station addition acknowledge message including a radio resource control (RRC) container, the RRC container including the enhanced handover indication,
• wherein the secondary base station addition request message includes the information associated with the enhanced handover indication based on information indicating a user equipment (UE) supports an enhanced handover process included in UE capability information, and
• wherein the enhanced handover process is a handover where a connection between a source secondary base station and the UE is maintained after transmission of an RRC reconfiguration message before a random access channel (RACH) access from the UE to the target secondary base station is performed.

A user equipment (UE) in a communication system, the UE comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to:
• transmit, to a master base station, UE capability information including information indicating the UE supports an enhanced handover process,
• receive, from the master base station, a radio resource control (RRC) reconfiguration message including an RRC container, the RRC container including an enhanced handover indication, and
• perform a synchronization to a target secondary base station after the UE receives the RRC reconfiguration message,
• wherein the enhanced handover process is a handover where a connection between the UE and a source secondary base station is maintained after a reception of the RRC reconfiguration message before the UE performs a random access channel (RACH) to the target secondary base station.