| 摘要 |
The application relates to HetNet mobility improvements and in particular to reduce handover failures. When handing over from a source small cell to a target small cell, it is likely that a UE can end up on a cell that does not have a prepared UE context, because typical small cells are single sector in nature. Then, RRC reestablishment can fail and the UE will be required to perform an attach or service request procedure to recover from the radio frequency (RF) loss. The attach or service request procedure can adversely impact the performance of the UE. The application proposes, in an attempt to improve handover success rate for the UE in a HetNet deployment, the source eNB prepares the overlay macro eNodeB in addition to a target small cell as handover candidates during handover decision making. The UE is informed about the target small cell and eNodeB using RRC messaging. After receiving handover command or detecting RF loss, the UE can try to connect with the target small cell. If UE is unable to connect (RACH FAILURE) to the target small cell, the UE will connect to the macro eNodeB (PRACH RACH & MACH RACH Response) |
