Method and equipment for handover

A method for supporting handover performed by a source base station related to an evolved packet system (EPS) in a mobile communication system, the method comprising:

• transmitting, to a mobility management entity (MME), a handover required message including information on an availability of a direct forwarding path for a data forwarding of the source base station;
• receiving, from the MME, a handover command message including bearer information for which a target base station related to a 5th generation system (5GS) has accepted the data forwarding;
• and
• forwarding a downlink data to the target base station based on the bearer information,
• wherein the availability of the direct forwarding path is used for session management function (SMF) related information which is transparently transferred to the target base station, and
• wherein the SMF related information indicates that the data forwarding is not possible or whether the direct forwarding path for the data forwarding is available.

A target base station related to a 5th generation system (5GS) for supporting handover in a mobile communication system, the target base station comprising:

• a transceiver;
• and
• a controller configured to:
• receive, from an access and mobility management function (AMF) via the transceiver, a handover request message containing session management function (SMF) related information which is transparent to the AMF,
• determine whether to accept a data forwarding,
• in case that the data forwarding is accepted, allocate a tunnel for the data forwarding based on the SMF related information,
• transmit, to the AMF via the transceiver, a handover request acknowledge message including information on the tunnel for the data forwarding, and
• receive, via the transceiver, a downlink data forwarded from a source base station related to an evolved packet system (EPS) according to the information on the tunnel,
• wherein the SMF related information indicates that the data forwarding is not possible or whether a direct forwarding path for the data forwarding is available.

A source base station related to an evolved packet system (EPS) for supporting handover in a mobile communication system, the source base station comprising:

• a transceiver;
• and
• a controller configured to:
• transmit, to a mobility management entity (MME) via the transceiver, a handover required message including information on an availability of a direct forwarding path for a data forwarding of the source base station,
• receive, from the MME via the transceiver, a handover command message including bearer information for which a target base station related to a 5th generation system (5GS) has accepted the data forwarding, and
• forward a downlink data to the target base station based on the bearer information,
• wherein the availability of the direct forwarding path is used for session management function (SMF) related information which is transparently transferred to the target base station, and
• wherein the SMF related information indicates that the data forwarding is not possible or whether the direct forwarding path for the data forwarding is available.