Content for  TS 25.367  Word version:  18.0.0

Top   Top   None   None   Next
1…   7…


1  Scopep. 5

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.

2  Referencesp. 5

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
  • References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
  • For a specific reference, subsequent revisions do not apply.
  • For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
TR 21.905: "Vocabulary for 3GPP Specifications".
TS 25.304: "UE procedures in idle mode and procedures for cell reselection in connected mode".
TS 25.331: "Radio Resource Control (RRC) protocol specification".
TS 23.011: "Service accessibility".
TS 22.220: "Service Requirements for Home NodeBs and Home eNodeBs".
TS 25.467: "UTRAN architecture for 3G Home Node B (HNB)".
TS 25.214: "Physical layer procedures (FDD)".

3  Definitions, symbols and abbreviationsp. 5

3.1  Definitionsp. 5

For the purposes of the present document, the following terms and definitions apply.
Acceptable Cell:
A cell that satisfies certain conditions as specified [2]. A UE can always attempt emergency calls on an acceptable cell.
CSG whitelist:
A list provided by NAS containing all the CSG Identities of the CSGs to which the subscriber belongs.
Available PLMN:
A PLMN for which the UE has found at least one cell and read its PLMN identity.
Barred Cell:
A cell a UE is not allowed to camp on.
Camped on a cell:
UE has completed the cell selection/reselection process and has chosen a cell. The UE monitors system information and (in most cases) paging information.
Camped on any cell:
UE is in idle mode and has completed the cell selection/reselection process and has chosen a cell irrespective of PLMN identity.
Closed Subscriber Group (CSG):
A Closed Subscriber Group identifies subscribers of an operator who are permitted to access one or more cells of the PLMN but which have restricted access (CSG cells).
CSG Cell:
A cell, part of the PLMN, broadcasting a CSG Indicator that is set to TRUE and a specific CSG identity. A CSG cell is accessible by the members of the closed subscriber group for that CSG identity.
CSG Identity (CSG ID):
An identifier broadcast by a CSG/Hybrid cell or cells and used by the UE to facilitate access for authorised members of the associated Closed Subscriber Group.
CSG member cell:
A cell broadcasting the identity of the selected PLMN, registered PLMN or equivalent PLMN and for which the CSG whitelist of the UE includes an entry comprising cell's CSG ID and the respective PLMN identity.
DRX cycle:
Individual time interval between monitoring Paging Occasion for a specific UE.
Equivalent PLMN list:
List of PLMNs considered as equivalent by the UE for cell selection, cell reselection , MBSFN Cluster selection MBSFN Cluster reselection and handover according to the information provided by the NAS.
Home NodeB (HNB):
A HNB is a customer-premises equipment that connects a 3GPP UE over UTRAN wireless air interface to a mobile operator's network using broadband IP backhaul.
HNB Name:
The Home NodeB Name is a broadcast string in free text format that provides a human readable name for the Home NodeB CSG identity.
Home PLMN:
A PLMN where the Mobile Country Code (MCC) and Mobile Network Code (MNC) of the PLMN identity are the same as the MCC and MNC of the IMSI.
Hybrid cell:
A cell broadcasting a CSG identity which is accessible as a CSG cell by UEs which are members of the CSG and as a normal cell by all other UEs.
Non-CSG Cell:
A cell that is not a CSG cell, e.g. a macro cell.
A local action in the UE invoked by a RRC procedure or an Idle Mode procedure.
Radio Access Mode:
Radio access mode of the cell, FDD or TDD.
Radio Access Technology:
Type of technology used for radio access, for instance UTRA or GSM.
Registered PLMN:
This is the PLMN on which certain Location Registration outcomes have occurred.
Registration Area:
(NAS) registration area is an area in which the UE may roam without a need to perform location registration, which is a NAS procedure.
Reserved Cell:
A cell on which camping is not allowed, except for particular UEs, if so indicated in the system information.
Restricted Cell:
A cell on which camping is allowed, but access attempts are disallowed for UEs whose access classes are indicated as barred.
Selected PLMN:
This is the PLMN that has been selected by the NAS, either manually or automatically.
Serving cell:
The cell on which the UE is camped.
Strongest cell:
The cell on a particular carrier that is considered strongest according to the layer 1 cell search procedure [7]. As the details of the layer 1 cell search are implementation dependent, the precise definition of 'strongest cell' is also implementation dependent.
Suitable Cell:
This is a cell on which an UE may camp.

3.2  Abbreviationsp. 6

For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
Access Stratum
Broadcast Control Channel
Connection Management
Core Network
Closed Subscriber Group
Discontinuous Reception
Evolved UMTS Terrestrial Radio Access
Frequency Division Duplex
General Packet Radio Service
Global System for Mobile Communications
Hierarchical Cell Structure
Home NodeB
International Mobile Subscriber Identity
Mobile Country Code
Mobility Management
Mobile Network Code
Non-Access Stratum
Paging Channel
Page Indicator
Page Indication Channel
Public Land Mobile Network
Radio Access Technology
Radio Resource Control
Service Access Point
Time Division Duplex
Temporary Mobile Group Identity
User Equipment
Universal Mobile Telecommunications System
UMTS Terrestrial Radio Access
UMTS Terrestrial Radio Access Network

4  Overviewp. 7

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.

5  CSG Identificationp. 8

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.

6  CSG Selectionp. 8

6.1  Manual CSG ID Selectionp. 8

Manual CSG ID selection enables a human user to select a CSG ID. In manual CSG ID selection the UE may scan all frequencies in the supported frequency bands and display a list of found CSG IDs or the corresponding HNB Names if broadcast by the CSG cells or hybrid cells, and indications as to whether the found CSG IDs and associated PLMN IDs are contained in the UE's CSG whitelist. When the user selects an entry in the list, the UE selects any CSG cell or hybrid cell among the ones with same CSG ID and PLMN ID. The UE may normally camp on the chosen cell if it is a CSG member cell or a hybrid cell.
During manual CSG ID selection a UE is allowed to perform Location Registration procedure on a CSG cell that is not a CSG member cell.
Based on the outcome of a Location Registration procedure initiated on a CSG cell, the UE's CSG whitelist is updated.
The UE is allowed to not support manual CSG ID selection in connected mode.

Up   Top   ToC