This document provides a high level description of the mobility procedures applicable to Home NodeB support in the current Release. Where appropriate, the reasons behind the agreements are provided. Throughout this document, unless otherwise stated, the UE is assumed to be a current Release UE that supports the Closed Subscriber Group (CSG) feature, whether it is actually a member of a CSG or not. A UE that does not support the CSG feature is not required to support any of the procedures stated in this document.

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A Home NodeB may provide restricted access to only UEs belonging to a Closed Subscriber Group (CSG). One or more of such cells providing restricted access, known as CSG cells, are identified by a unique numeric identifier called CSG Identity. To facilitate access control, a UE with CSG subscription would have an CSG whitelist, which contains one or more CSG Identities associated with the CSG cells on which the UE is allowed access. The UE uses the CSG whitelist along with the CSG Identity and associated PLMN ID broadcast by the CSG Cells in CSG cell selection and reselection. A HNB can also be operated as a hybrid cell. A hybrid cell is accessed as a CSG cell by a UE whose CSG whitelist contains the cell's CSG ID and associated PLMN ID and as a normal cell by all other UEs. Members of the CSG are expected to receive preferential access according to [5]. In addition, manual selection of CSG Identity is introduced, which enables the human user to manually select a CSG Identity for UE to camp on. This document provides high level descriptions and procedures of the mobility features to support CSG deployment in the current Release. The following areas will be covered in the subsequent chapters:

• Identifiers associated with the CSG framework
• Manual selection of CSG Identity
• Measurement rules for CSG Cells
• Cell reselection to a CSG cell, from a CSG cell, and between CSG cells
• Handover to a CSG cell, from a CSG cell, and between CSG cells, where applicable
• Measurement rules, (re)selection and handover procedures for hybrid cells.

One or more Closed Subscriber Group (CSG) cells are identified by a unique numeric identifier called CSG Identity or CSG ID. A UE belonging to a CSG has the corresponding CSG ID and associated PLMN ID in its CSG whitelist. The CSG whitelist is maintained and provided by NAS. The CSG ID is broadcast in system information by the CSG cell or hybrid cell, and used by the UE for cell (re)selection and handover purposes. A cell may optionally broadcast the CSG Indicator, whose presence and value of TRUE indicates the cell is a CSG cell. The absence of the CSG indicator in a cell which broadcasts a CSG identity indicates that it is a hybrid cell. A CSG cell or hybrid cell may broadcast the HNB Name, a textual identifier, in system information. The HNB Name can be used to aid the human user in manual selection of a CSG ID. At the physical layer, a CSG cell is identified by its carrier frequency (UARFCN) and Primary Scrambling Code (PSC). A set of PSCs could be reserved for CSG deployment and this reserved PSC range may be signalled in system information. The PSC of a CSG cell belongs to the reserved PSC range if broadcast. On the mixed carrier frequency shared by both non-CSG cells (UMTS macro cells) and CSG cells, CSG cells broadcast in system information the PSC range reserved by the network for CSG cells. The non-CSG cells may also broadcast the reserved PSC range. The reserved PSC range is only applicable to the UARFCN within the PLMN where the UE received this information. The UE considers the last received reserved PSC range to be valid within the entire PLMN for the duration of 24 hours. The UE may use the reserved PSC information for CSG cell search and (re)selection purposes, according to UE's implementation. Non-CSG cells and CSG cells may broadcast indications of one or more carrier frequencies used for dedicated CSG deployment. This information may be used by a UE to avoid unnecessary measurements on that frequency even when cell measurement rules would require measurements of this carrier frequency. Indications of which carrier frequencies are dedicated to CSG-only deployment may be signalled in system information and are applicable only in the cell where this information is broadcast.