Apparatus, system and method for DC (dual connectivity)
A UE ( 10 ) provides information on potential S′eNB(s). The information is forwarded from an MeNB ( 20 _ 1 ) to an M′eNB ( 20 _ 2 ) such that the M′eNB ( 20 _ 2 ) can determine, before the handover happens, whether the M′eNB ( 20 _ 2 ) will configure a new SeNB (S′eNB) and which S′eNB the M′eNB ( 20 _ 2 ) will configure. In one of options, the MeNB ( 20 _ 1 ) derives a key S′-KeNB for communication protection between the UE ( 10 ) and the S′eNB ( 30 _ 1 ), and send the S′-KeNB to the M′eNB ( 20 _ 2 ). In another option, the M′eNB ( 20 _ 2 ) derives the S′-KeNB from a key KeNB* received from the MeNB ( 20 _ 1 ). The M′eNB ( 20 _ 2 ) sends the S′-KeNB to the S′eNB ( 30 _ 1 ). Moreover, there are also provided several variations to perform SeNB Release, SeNB Addition, Bearer Modification and the like, in which the order and/or timing thereof can be different during the handover procedure.
1. A mobile communication system for DC (Dual Connectivity), the mobile communication system comprising:
a UE (User Equipment);
a MeNB (Master eNodeB);
aSeNB (Secondary eNodeB);
a MME (Mobility Management Entity); and
a S-GW (Serving Gateway),
wherein the UE is connected to the MeNB and the SeNB,
wherein C-Plane (Control Plane) signaling is performed by interfaces between the MeNB and the SeNB and between the MeNB and the MME, and U-Plane (User Plane) data is transferred from the S-GW to the MeNB and the SeNB,
wherein upon a handover from a source MeNB to a target eNB,
the source MeNB sends a Handover Request message to the target eNB,
the source MeNB receives a Handover Request Acknowledge message from the target eNB,
the source MeNB releases a source SeNB,
the source MeNB sends a RRCConnectionReconfiguration message to the UE to inform the UE that the source MeNB has released the source SeNB, and
the UE sends a RRCConnectionReconfigurationComplete message to the target eNB,
wherein the target eNB adds a new SeNB, from among the source SeNB or another SeNB, if a resource of the new SeNB is available, and
wherein security context is deleted at the UE and the source SeNB.
2. The mobile communication system according to claim 1 , further comprising:
wherein the target eNB derives a new security context when the new SeNB is added.
3. The mobile communication system according to claim 1 , further comprising:
wherein the target eNB sends a Path Switch Request message to the MME,
the MME sends a Modify Bearer Request message to the S-GW,
the S-GW sends a Modify Bearer Response message to the MME, and
the MME sends a Path Switch Request Acknowledge to the target eNB.
4. A base station (eNodeB) in a mobile communication system for DC (Dual Connectivity) including at least a UE (User Equipment), a MeNB (Master eNodeB), a SeNB (Secondary eNodeB), a MME (Mobility Management Entity), and a S-GW (Serving Gateway), wherein the UE is connected to the MeNB and the SeNB, C-Plane (Control Plane) signaling is performed by interfaces between the MeNB and the SeNB and between the MeNB and the MME, and U-Plane (User Plane) data is transferred from the S-GW to the MeNB and the SeNB, upon a handover from a source MeNB to a target eNB, the source MeNB comprising:
a sender configured to send a Handover Request message to the target eNB;
a receiver configured to receive a Handover Request Acknowledge message from the target eNB; and
a controller configured to release a source SeNB,
wherein the UE receives a RRCConnectionReconfiguration message from the source MeNB, the RRCConnectionReconfiguration message informing the UE that the source MeNB has released the source SeNB, and sends a RRCConnectionReconfigurationComplete message to the target eNB,
wherein the target eNB adds a new SeNB, from among the source SeNB or another SeNB, if a resource of the new SeNB is available; and
wherein security context is deleted at the UE and the source SeNB.
5. The base station according to claim 4 , further comprising:
wherein the target eNB derives a new security context when the new SeNB is added.
6. The base station according to claim 4 , further comprising:
wherein the target eNB sends a Path Switch Request message to the MME,
the MME sends a Modify Bearer Request message to the S-GW,
the S-GW sends a Modify Bearer Response message to the MME, and
the MME sends a Path Switch Request Acknowledge to the target eNB.
7. A UE (User Equipment) in a mobile communication system for DC (Dual Connectivity) including at least a MeNB (Master eNodeB), a SeNB (Secondary eNodeB), a MME (Mobility Management Entity), and a S-GW (Serving Gateway), wherein the UE is connected to the MeNB and the SeNB, C-Plane (Control Plane) signaling is performed by interfaces between the MeNB and the SeNB and between the MeNB and the MME, and U-Plane (User Plane) data is transferred from the S-GW to the MeNB and the SeNB,
the UE comprising:
upon a handover from a source MeNB to a target eNB,
a receiver that receives a RRCConnectionReconfiguration message from the source MeNB, the RRCConnectionReconfiguration message informing the UE that the source MeNB has released a source SeNB; and
a transmitter that sends a RRCConnectionReconfigurationComplete message to the target eNB;
wherein the source MeNB sends a Handover Request message to the target eNB,
receives a Handover Request message Acknowledge from the target eNB, and
releases the source SeNB,
wherein the target eNB adds a new SeNB, from among the source SeNB or another SeNB, if a resource of the new SeNB is available, and
wherein security context is deleted at the UE and the source SeNB.
8. The UE according to claim 7 , further comprising:
wherein the target eNB derives a new security context when the new SeNB is added.
9. The UE according to claim 7 , further comprising:
wherein the target eNB sends a Path Switch Request message to the MME,
the MME sends a Modify Bearer Request message to the S-GW,
the S-GW sends a Modify Bearer Response message to the MME, and
the MME sends a Path Switch Request Acknowledge to the target eNB.
10. A method of a mobile communication system for DC (Dual Connectivity) including a UE (User Equipment), a MeNB (Master eNodeB), a SeNB (Secondary eNodeB), a MME (Mobility Management Entity), and a S-GW (Serving Gateway), wherein the UE is connected to the MeNB and the SeNB, C-Plane (Control Plane) signaling is performed by interfaces between the MeNB and the SeNB and between the MeNB and the MME, and U-Plane (User Plane) data is transferred from the S-GW to the MeNB and the SeNB, the method comprising:
upon a handover from a source MeNB to a target eNB,
sending a Handover Request message to the target eNB;
receiving a Handover Request Acknowledge message from the target eNB;
releasing a source SeNB;
receiving a RRCConnectionReconfiguration message from the source MeNB, the RRCConnectionReconfiguration message informing the UE of the releasing of the source SeNB; and
sending a RRCConnectionReconfigurationComplete message to the target eNB,
wherein the target eNB adds a new SeNB, from among the source SeNB or another SeNB, if a resource of the new SeNB is available, and
wherein security context is deleted at the UE and the source SeNB.
11. The method according to claim 10 , further comprising:
wherein the target eNB derives a new security context when the new SeNB is added.
12. The method according to claim 10 , further comprising:
wherein the target eNB sends a Path Switch Request message to the MME,
the MME sends a Modify Bearer Request message to the S-GW,
the S-GW sends a Modify Bearer Response message to the MME, and
the MME sends a Path Switch Request Acknowledge to the target eNB.
13. A method of a base station (eNodeB) in a mobile communication system for DC (Dual Connectivity) including at least a UE (User Equipment), a MeNB (Master eNodeB), a SeNB (Secondary eNodeB), a MME (Mobility Management Entity), and a S-GW (Serving Gateway), wherein the UE is connected to the MeNB and the SeNB, C-Plane (Control Plane) signaling is performed by interfaces between the MeNB and the SeNB and between the MeNB and the MME, and U-Plane (User Plane) data is transferred from the S-GW to the MeNB and the SeNB, the method comprising:
upon a handover from a source MeNB to a target eNB,
sending a Handover Request message to the target eNB and;
receiving a Handover Request Acknowledge message from the target eNB; and
releasing a source SeNB,
wherein the UE receives a RRCConnectionReconfiguration message from the source MeNB, the RRCConnectionReconfiguration message informing the UE that the source MeNB has released the source SeNB, and sends a RRCConnectionReconfigurationComplete message to the target eNB,
wherein the target eNB adds a new SeNB, from among the source SeNB or another SeNB, if a resource of the new SeNB is available, and
wherein security context is deleted at the UE and the source SeNB.
14. The method according to claim 13 , further comprising:
wherein the target eNB derives a new security context when the new SeNB is added.
15. The method according to claim 13 , further comprising:
wherein the target eNB sends a Path Switch Request message to the MME,
the MME sends a Modify Bearer Request message to the S-GW,
the S-GW sends a Modify Bearer Response message to the MME, and
the MME sends a Path Switch Request Acknowledge to the target eNB.
16. A method of a UE (User Equipment) in a mobile communication system for DC (Dual Connectivity) including at least a MeNB (Master eNodeB), a SeNB (Secondary eNodeB), a MME (Mobility Management Entity), and a S-GW (Serving Gateway), wherein the UE is connected to the MeNB and the SeNB, C-Plane (Control Plane) signaling is performed by interfaces between the MeNB and the SeNB and between the MeNB and the MME, and U-Plane (User Plane) data is transferred from the S-GW to the MeNB and the SeNB, the method comprising:
upon a handover from a source MeNB to a target eNB,
receiving a RRCConnectionReconfiguration message from the source MeNB, the RRCConnectionReconfiguration message informing the UE that the source MeNB has released a source SeNB; and
sending a RRCConnectionReconfigurationComplete message to the target eNB;
wherein the source MeNB sends a Handover Request message to the target eNB,
receives a Handover Request message Acknowledge from the target eNB, and
releases the source SeNB,
wherein the target eNB adds a new SeNB, from among the source SeNB or another SeNB, if a resource of the new SeNB is available, and
wherein security context is deleted at the UE and the source SeNB.
17. The method according to claim 16 , further comprising:
wherein the target eNB derives a new security context when the new SeNB is added.
18. The method according to claim 16 , further comprising:
wherein the target eNB sends a Path Switch Request message to the MME,
the MME sends a Modify Bearer Request message to the S-GW,
the S-GW sends a Modify Bearer Response message to the MME, and
the MME sends a Path Switch Request Acknowledge to the target eNB.