Method and equipment for handover
The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method and equipment for handover are provided. The method includes informing, by a source base station, a source core network whether a direct data forwarding path is available, determining, by the source core network, whether to use direct data forwarding or indirect data forwarding, informing, by the source core network, a target core network of information of direct data forwarding, indirect data forwarding or data forwarding being not possible, informing, by the target core network, a target base station of the information of direct data forwarding, indirect data forwarding or data forwarding being not possible, and allocating, by the target base station, tunnel information for data forwarding.
1. A method for supporting handover performed by a target base station related to a 5 th generation system (5GS) in a mobile communication system, the method comprising:
receiving, from an access and mobility management function (AMF), a handover request message containing session management function (SMF) related information which is transparent to the AMF;
determining whether to accept a data forwarding;
in case that the data forwarding is accepted, allocating a tunnel for the data forwarding based on the SMF related information;
transmitting, to the AMF, a handover request acknowledge message including information on the tunnel for the data forwarding; and
receiving 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.
2. The method of claim 1 ,
wherein the handover request message includes mapping information between at least one evolved-universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) identifier and at least one quality of service (QoS) flow identifier.
3. The method of claim 2 ,
wherein in case that the SMF related information indicates that the direct forwarding path is available, the information on the tunnel includes information on at least one E-RAB accepted for the data forwarding.
4. The method of claim 2 ,
wherein in case that an indirect data forwarding is applied, the information on the tunnel includes information on at least one protocol data unit (PDU) session associated with at least one QoS flow accepted for the data forwarding.
5. The method of claim 1 ,
wherein the SMF related information is based on an availability of the direct forwarding path of the source base station.
6. The method of claim 1 ,
wherein the handover request message includes information on a handover type indicating an EPS-to-5GS handover.
7. 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 5 th 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.
8. The method of claim 7 ,
wherein the SMF related information is used to allocate a tunnel for the data forwarding.
9. The method of claim 7 ,
wherein the bearer information includes at least one evolved-universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) identifier for the data forwarding.
10. The method of claim 7 ,
wherein the handover command message includes information on a handover type indicating an EPS-to-5GS handover.
11. A target base station related to a 5 th 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.
12. The target base station of claim 11 ,
wherein the handover request message includes mapping information between at least one evolved-universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) identifier and at least one quality of service (QoS) flow identifier.
13. The target base station of claim 12 ,
wherein in case that the SMF related information indicates that the direct forwarding path is available, the information on the tunnel includes information on at least one E-RAB accepted for the data forwarding.
14. The target base station of claim 12 ,
wherein in case that an indirect data forwarding is applied, the information on the tunnel includes information on at least one protocol data unit (PDU) session associated with at least one QoS flow accepted for the data forwarding.
15. The target base station of claim 11 ,
wherein the SMF related information is based on an availability of the direct forwarding path of the source base station.
16. The target base station of claim 11 ,
wherein the handover request message includes information on a handover type indicating an EPS-to-5GS handover.
17. 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 5 th 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.
18. The source base station of claim 17 ,
wherein the SMF related information is used to allocate a tunnel for the data forwarding.
19. The source base station of claim 17 ,
wherein the bearer information includes at least one evolved-universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) identifier for the data forwarding.
20. The source base station of claim 17 ,
wherein the handover command message includes information on a handover type indicating an EPS-to-5GS handover.