CSG and Hybrid HeNB Cells

In presence of allowed cells, a UE performs reselection for intra-frequency mobility as if with regular cells. An allowed cell can either be on in the UE's CSG whitelist, or a hybrid cell. In ranking and reselection, the UE may ignore all CSG cells that are known to be not allowed. In case of inter-frequency mobility, the UE prioritizes CSG cells that are the UE's whitelist, irrespective the general network priorities for frequencies. As for inter-RAT, LTE supports both inbound and outbound mobility.

When IDLE, and in instances where different CSG HeNB use different mixed carrier, all CSG cells broadcast the PCI values reserved by the network for use by CSG cells. This broadcast is optional. It is also optional that non-CSG cells on the mixed carrier can send this information in system information. A UE checks the suitability of CSG cells based on whether they're the UE's whitelist. Manual selection of CSG cell is supported.

When CONNECTED, the UE performs measurement and mobility procedures as set by the network. A UE is not required to support manual CSG selection when connected.

The above descriptions apply for mobility inbound to a CSG or hybrid cell. For outbound mobility, a UE performs normal IDLE mode reselection and CONNECTED mode handover procedures.

The general procedure for a handover from eNB/HeNB to a HeNB's CSG or hybrid cell is shown in Figure 13.4. When the Source EUTRAN cell (eNB or HeNB) decides that a handover is required, a Handover ...

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