3GPP TS 25.304

3GPP TS 25.304
3GPP TS 25.304 V6.10.0 (2008-03)
Technical Specification
3rd Generation Partnership Project;
Technical Specification Group Radio Access Network;
User Equipment (UE) procedures in idle mode
and procedures for cell reselection in connected mode
(Release 6)
The present document has been developed within the 3rd Generation Partnership Project (3GPP TM) and may be further elaborated for the purposes of 3GPP.
The present document has not been subject to any approval process by the 3GPP Organisational Partners and shall not be implemented.
This Specification is provided for future development work within 3GPP only. The Organisational Partners accept no liability for any use of this Specification.
Specifications and reports for implementation of the 3GPP TM system should be obtained via the 3GPP Organisational Partners' Publications Offices.
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Keywords
UMTS, radio
3GPP
Postal address
3GPP support office address
650 Route des Lucioles - Sophia Antipolis
Valbonne - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Internet
http://www.3gpp.org
Copyright Notification
No part may be reproduced except as authorized by written permission.
The copyright and the foregoing restriction extend to reproduction in all media.
© 2008, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC).
All rights reserved.
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Contents
Foreword ............................................................................................................................................................5
1
Scope ........................................................................................................................................................6
2
References ................................................................................................................................................6
3
Definitions and abbreviations...................................................................................................................7
3.1
3.2
4
4.1
4.2
4.3
5
Definitions ......................................................................................................................................................... 7
Abbreviations..................................................................................................................................................... 8
General description of Idle mode ...........................................................................................................10
Overview.......................................................................................................................................................... 10
Functional division between AS and NAS in Idle mode ................................................................................. 11
Service type in Idle and Connected Mode ....................................................................................................... 13
Process and procedure descriptions........................................................................................................14
5.1
PLMN selection ............................................................................................................................................... 14
5.1.1
General ....................................................................................................................................................... 14
5.1.2
Support for PLMN Selection...................................................................................................................... 14
5.1.2.1
General ................................................................................................................................................. 14
5.1.2.2
UTRA case ........................................................................................................................................... 14
5.1.2.3
GSM case ............................................................................................................................................. 15
5.2
Cell selection and reselection in idle mode...................................................................................................... 15
5.2.1
Introduction................................................................................................................................................ 15
5.2.2
States and state transitions in Idle Mode .................................................................................................... 16
5.2.2.1
Cell Selection process overview........................................................................................................... 16
5.2.2.2
Camped normally state overview ......................................................................................................... 17
5.2.2.3
Connected mode State overview .......................................................................................................... 17
5.2.2.4
Any cell selection State overview......................................................................................................... 17
5.2.2.5
Camped on any cell State overview...................................................................................................... 17
5.2.3
Cell Selection Process ................................................................................................................................ 18
5.2.3.1
UTRA case ........................................................................................................................................... 18
5.2.3.1.1
Description...................................................................................................................................... 18
5.2.3.1.2
Criteria ............................................................................................................................................ 18
5.2.3.2
GSM case ............................................................................................................................................. 19
5.2.4
Void............................................................................................................................................................ 19
5.2.5
Camped Normally State ............................................................................................................................. 19
5.2.5.1
UTRA case ........................................................................................................................................... 19
5.2.5.2
GSM case ............................................................................................................................................. 19
5.2.6
Cell Reselection Evaluation Process .......................................................................................................... 19
5.2.6.1
UTRA case ........................................................................................................................................... 19
5.2.6.1.0
Use of MBMS PL ........................................................................................................................... 19
5.2.6.1.1
Measurement rules for cell re-selection when HCS is not used...................................................... 19
5.2.6.1.1a
High mobility state when HCS is not used ..................................................................................... 20
5.2.6.1.2
Measurement rules for cell re-selection when HCS is used ............................................................ 20
5.2.6.1.3
Highest ranked cells with cell reservations, access restrictions or unsuitable for normal
camping........................................................................................................................................... 22
5.2.6.1.4
Cell Reselection Criteria ................................................................................................................. 23
5.2.6.1.5
Cell reselection parameters in system information broadcasts........................................................ 27
5.2.6.2
GSM case ............................................................................................................................................. 29
5.2.7
Cell Selection when leaving connected mode ............................................................................................ 29
5.2.7.1
UTRA case ........................................................................................................................................... 29
5.2.7.2
GSM case ............................................................................................................................................. 30
5.2.8
Any Cell Selection state ............................................................................................................................. 30
5.2.9
Camped on Any Cell State ......................................................................................................................... 30
5.2.9.1
UTRA case ........................................................................................................................................... 30
5.2.9.2
GSM case ............................................................................................................................................. 30
5.3
Cell Reservations and Access Restrictions ...................................................................................................... 30
5.3.1
UTRA cells ................................................................................................................................................ 30
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5.3.1.1
5.3.1.2
5.3.1.3
5.3.2
5.4
5.4.1
5.4.2
5.4.3
5.4.4
5.5
6
6.1
6.2
6.3
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Cell status and cell reservations............................................................................................................ 30
Access Control...................................................................................................................................... 31
Emergency Call .................................................................................................................................... 32
GSM cells................................................................................................................................................... 32
Cell Selection and Reselection Processes in RRC Connected Mode............................................................... 32
Void............................................................................................................................................................ 32
Void............................................................................................................................................................ 32
Cell Reselection Process in RRC connected mode .................................................................................... 32
Cell Selection Process in RRC connected mode ........................................................................................ 32
Location Registration....................................................................................................................................... 32
Broadcast information receiving ............................................................................................................32
Reception of System Information .................................................................................................................... 32
Cell Broadcast in Idle Mode, CELL_PCH and URA_PCH............................................................................. 33
MBMS Services............................................................................................................................................... 33
7
Void........................................................................................................................................................33
8
Paging and SCCPCH selection ..............................................................................................................33
8.1
8.2
8.3
8.4
8.4.1
8.4.1.1
8.4.1.2
8.4.2
Paging Channel selection................................................................................................................................. 33
SCCPCH selection when entering Connected mode ....................................................................................... 34
Discontinuous Reception for Paging................................................................................................................ 34
Discontinuous Reception for MBMS............................................................................................................... 36
Discontinuous Reception for MCCH ......................................................................................................... 36
Discontinuous Reception via MICH..................................................................................................... 36
Discontinuous Reception via MODIFIED SERVICES INFORMATION ........................................... 36
Discontinuous Reception for MTCH ......................................................................................................... 37
8a
MBMS Notification ...............................................................................................................................37
9
Void........................................................................................................................................................37
10
Void........................................................................................................................................................37
Annex A (informative):
Change history ...............................................................................................37
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Foreword
This Technical Specification has been produced by the 3rd Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates,
etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
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Scope
The present document specifies the Access Stratum (AS) part of the Idle Mode procedures applicable to a UE. The nonaccess stratum (NAS) part of Idle mode procedures and processes is specified in [5].
The present document also specifies cell selection and reselection processes applicable to UEs in connected mode.
Invocation of these processes is described in [4].
The present document specifies the model for the functional division between the NAS and AS in a UE.
The present document applies to all UEs that support at least UTRA, including multi-RAT UEs as described in 3GPP
specifications, in the following cases:
-
When the UE is camped on a UTRA cell;
-
When the UE is searching for a cell to camp on;
NOTE:
The details for those cases are described in the specifications of the other RAT.
The present document presents also examples of inter-layer procedures related to the idle mode processes and describes
idle mode functionality of a dual RAT UTRA/GSM UE.
The present document also specifies how idle-mode and reselection procedures are affected by the provision of MBMS
services.
2
References
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.
[1]
3GPP TS 43.022: "Functions related to Mobile Station in idle mode and group receive mode".
[2]
3GPP TS 25.301: "Radio Interface Protocol Architecture".
[3]
3GPP TS 25.303: "Interlayer Procedures in Connected Mode".
[4]
3GPP TS 25.331: "Radio Resource Control (RRC); protocol specification".
[5]
3GPP TS 23.122: "NAS functions related to Mobile Station (MS) in idle mode ".
[6]
3GPP TR 25.922: "Radio Resource Management Strategies".
[7]
3GPP TS 25.211: "Physical channels and mapping of transport channels onto physical channels
(FDD)".
[8]
3GPP TS 25.221: "Physical channels and mapping of transport channels onto physical channels
(TDD)".
[9]
3GPP TS 22.011: "Service accessibility".
[10]
3GPP TS 25.133: "Requirements for Support of Radio Resource Management (FDD)".
[11]
3GPP TS 25.123: "Requirements for Support of Radio Resource Management (TDD)".
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[12]
3GPP TR 21.905: "Vocabulary for 3GPP Specifications".
[13]
3GPP TS 45.008: "Radio subsystem link control".
[14]
3GPP TS 25.214: "Physical layer procedures (FDD)".
[15]
3GPP TS 25.224: "Physical Layer Procedures (TDD)".
[16]
3GPP TS 24.008: "Mobile radio interface layer 3 specification, Core Network Protocols - Stage 3".
[17]
3GPP TS 25.346: "Introduction of the Multimedia Broadcast Multicast Service (MBMS) in the
Radio Access Network (Stage-2)".
3
Definitions and abbreviations
3.1
Definitions
For the purposes of the present document, the following definitions and the definitions in [12] apply.
Acceptable Cell: A cell that satisfies certain conditions as specified in 4.3. A UE can always attempt emergency calls
on an acceptable cell.
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.
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 and
handover according to the information provided by the NAS.
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.
Location Registration (LR): UE registers its presence in a registration area, for instance regularly or when entering a
new registration area.
Maximum DRX cycle: Time interval for the longest possible DRX cycle in a cell.
MBMS Activated Service: An MBMS service that the UE has joined (multicast) or is interested in (broadcast).
MBMS Preferred Layer (PL): A frequency layer that is indicated by the UTRAN to be preferred for camping for
MBMS purposes.
Paging Block Periodicity (PBP): Period of the occurrence of Paging Blocks. (For FDD, PBP = 1).
Paging Message Receiving Occasion (TDD only): The frame where the UE receives actual paging message.
Paging occasion:
(FDD) The SFN of the PICH frame where the UE monitors its paging indicator (i.e. the SFN of the PCCPCH frame in
which the PICH frame begins).
(TDD) The paging block, which consists of several frames. The value of Paging Occasion is equal to the first frame of
the Paging Block.
Process: 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.
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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 [5].
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
[14][15]. 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. For a UTRA cell, the criteria are defined in subclause 4.3, and
for a GSM cell the criteria are defined in [1].
3.2
Abbreviations
For the purposes of the present document, the following abbreviations apply:
AS
BCCH
CM
CN
DRX
DSCH
FDD
GC
GPRS
GSM
HCS
IMSI
MBMS
MCC
MCCH
MICH
MM
MNC
MSCH
MTCH
NAS
NI
PCH
PI
PICH
PLMN
RAT
RRC
SAP
TDD
TMGI
UE
UMTS
UTRA
UTRAN
Access Stratum
Broadcast Control Channel
Connection Management
Core Network
Discontinuous Reception
Downlink Shared Channel
Frequency Division Duplex
General Control (SAP)
General Packet Radio Service
Global System for Mobile Communications
Hierarchical Cell Structure
International Mobile Subscriber Identity
Multimedia Broadcast-Multicast Service
Mobile Country Code
MBMS point-to-multipoint Control Channel
MBMS notification Indicator Channel
Mobility Management
Mobile Network Code
MBMS point-to-multipoint Scheduling Channel
MBMS point-to-multipoint Traffic Channel
Non-Access Stratum
(MBMS) Notification Indicator
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
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General description of Idle mode
4.1
Overview
3GPP TS 25.304 V6.10.0 (2008-03)
When a UE is switched on, a public land mobile network (PLMN) is selected and the UE searches for a suitable cell of
this PLMN to camp on. Criteria for cell selection and cell re-selection between radio access technologies (RATs)
described in this document only consider radio criteria. In addition to RAT, the PLMN type may differ as well. In this
specification, the term PLMN is used as a generic term covering both GSM MAP and ANSI-41 type of PLMNs.
According to the type of PLMN, the way to identify it can be different. If the PLMN type is GSM, the PLMN is
identified by 'PLMN identity' and if the PLMN type is ANSI-41, the PLMN is identified by 'SID'
The NAS shall provide a list of equivalent PLMNs, if available, that the AS shall use for cell selection and cell
reselection.
The UE searches for a suitable cell of the selected PLMN and chooses that cell to provide available services, and tunes
to its control channel. This choosing is known as "camping on the cell". The UE will, if necessary, then register its
presence, by means of a NAS registration procedure, in the registration area of the chosen cell and as outcome of a
successful Location Registration the selected PLMN becomes the registered PLMN [5].
If the UE finds a more suitable cell, it reselects onto that cell and camps on it. If the new cell is in a different registration
area, location registration is performed.
If necessary, the UE shall search for higher priority PLMNs at regular time intervals as described in [9] and search for a
suitable cell if another PLMN has been selected by NAS.
NOTE: For RRC connected mode the requirements for the search for higher priority PLMNs are defined in [4].
If the UE loses coverage of the registered PLMN, either a new PLMN is selected automatically (automatic mode), or an
indication of which PLMNs are available is given to the user, so that a manual selection can be made (manual mode).
Registration is not performed by UEs only capable of services that need no registration.
The purpose of camping on a cell in idle mode is fourfold:
a) It enables the UE to receive system information from the PLMN.
b) When registered and if the UE wishes to establish an RRC connection, it can do this by initially accessing the
network on the control channel of the cell on which it is camped.
c) If the PLMN receives a call for the registered UE, it knows (in most cases) the registration area of the cell in
which the UE is camped. It can then send a "paging" message for the UE on control channels of all the cells in
the registration area. The UE will then receive the paging message because it is tuned to the control channel of a
cell in that registration area and the UE can respond on that control channel.
d) It enables the UE to receive cell broadcast services.
If the UE is unable to find a suitable cell to camp on, or the USIM is not inserted, or if the location registration failed
(except for LR rejected with cause #12, cause #14 or cause #15, see [5] and [16]), it attempts to camp on a cell
irrespective of the PLMN identity, and enters a "limited service" state in which it can only attempt to make emergency
calls.
The idle mode tasks can be subdivided into three processes:
-
PLMN selection;
-
Cell selection and reselection;
-
Location registration.
The relationship between these processes is illustrated in Figure 1.
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Automatic mode
Manual Mode
PLMN Selection
Indication
to user
Location
Registration
response
PLMNs
available
PLMN
selected
NAS Control
Cell Selection
and Reselection
Radio measurements
Registration
Area
changes
CM requests
Location
Registration
Figure 1: Overall Idle Mode process
4.2
Functional division between AS and NAS in Idle mode
Table 1 presents the functional division between UE non-access stratum (NAS) and UE access stratum (AS) in idle
mode. The NAS part is specified in [5] and the AS part in the present document. Examples of different idle mode
procedures are presented in Clause 10.
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Table 1: Functional division between AS and NAS in idle mode
Idle Mode
Process
PLMN Selection
UE Non-Access Stratum
Maintain the list of allowed PLMN types. It can be
GSM-MAP only, ANSI-41 only or both.
Maintain a list of PLMNs in priority order according
to [5]. Select a PLMN using automatic or manual
mode as specified in [5] and request AS to select
a cell belonging to this PLMN. For each PLMN,
associated RAT(s) may be set.
Evaluate reports of available PLMNs from AS for
PLMN selection.
UE Access Stratum
Search for available PLMNs.
If associated RAT(s) is (are) set for the
PLMN, search in this (these) RAT(s) and
other RAT(s) for that PLMN as specified in
[5].
Perform measurements to support PLMN
selection.
Synchronise to a broadcast channel to
identify found PLMNs.
Maintain a list of equivalent PLMN identities.
Report available PLMNs with associated
PLMN type and RAT to NAS on request
from NAS or autonomously.
Cell
Selection
Control cell selection for example by indicating
RAT(s) associated with the selected PLMN to be
used initially in the search of a cell in the cell
selection. NAS is also maintaining lists of
forbidden registration areas.
It shall respect allowed PLMN types
indications from NAS.
Perform measurements needed to support
cell selection.
Detect and synchronise to a broadcast
channel. Receive and handle broadcast
information. Forward NAS system
information to NAS.
Search for a suitable cell. The cells
broadcast their 'PLMN identity' (GSM-MAP)
or 'SID' in the system information. Respond
to NAS whether such cell is found or not.
If associated RATs is (are) set for the
PLMN, perform the search in this (these)
RAT(s) and other RATs for that PLMN as
specified in [5].
Cell
Reselection
Control cell reselection by for example,
maintaining lists of forbidden registration areas.
Maintain a list of equivalent PLMN identities and
provide the list to AS.
Maintain a list of forbidden LAs and provide the list
to AS
Location
registration
Register the UE as active after power on.
Register the UE's presence in a registration area,
for instance regularly or when entering a new
registration area.
Maintain lists of forbidden LAs.
Deregister UE when shutting down.
3GPP
If such a cell is found, the cell is selected to
camp on.
Perform measurements needed to support
cell reselection.
Detect and synchronise to a broadcast
channel. Receive and handle broadcast
information. Forward NAS system
information to NAS.
Change cell if a more suitable cell is found.
Report registration area information to
NAS.
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Maintain priority information for various services
and participate in service selection.
Maintain a list of TMGIs of activated
services.
Indicate to AS if an offered session has previously
been received.
Notify NAS of service availability and
request NAS to prioritise in case of service
conflicts.
Report to NAS when an activated service
requires action.
Receive and handle the MCCH and MTCH,
and, if applicable, the MSCH and MICH.
4.3
Service type in Idle and Connected Mode
This clause defines the level of service that may be provided by the network to a UE in Idle mode and Connected Mode.
The action of camping on a cell is necessary to get access to some services. Three levels of services are defined for UE:
-
Limited service (emergency calls on an acceptable cell)
-
Normal service (for public use on a suitable cell)
-
Operator service (for operators only on a reserved cell)
Furthermore, the cells are categorised according to which services they offer:
acceptable cell:
An "acceptable cell" is a cell on which the UE may camp to obtain limited service (originate emergency calls). Such a
cell shall fulfil the following requirements, which is the minimum set of requirements to initiate an emergency call in a
UTRAN network:
-
The cell is not barred, see subclause 5.3.1.1;
-
The cell selection criteria are fulfilled, see subclause 5.2.3.1.2;
suitable cell:
A "suitable cell" is a cell on which the UE may camp on to obtain normal service. Such a cell shall fulfil all the
following requirements.
-
The cell shall be part of either:
ƒ
the selected PLMN, or:
ƒ
the registered PLMN, or:
ƒ
a PLMN of the Equivalent PLMN list
according to the latest information provided by the NAS.
-
The cell is not barred, see subclause 5.3.1.1;
-
The cell is part of at least one LA that is not part of the list of "forbidden LAs for roaming" [9], which belongs to
a PLMN that fulfills the first bullet above;
-
The cell selection criteria are fulfilled, see subclause 5.2.3.1.2.
If the IE “Multiple PLMN List” [4] is broadcast in the cell, the cell is considered to be part of all LAs with LAIs
constructed from the PLMN identities in the “Multiple PLMN List” and the LAC broadcast in the cell.
barred cell:
A cell is barred if it is so indicated in the system information [4].
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reserved cell:
A cell is reserved if it is so indicated in system information [4].
Exceptions to these definitions are applicable for UEs camped on a cell that belongs to a LA that is forbidden for
regional provision of service, and during emergency calls.
A cell that belongs to a LA that is forbidden for regional provision service ([5], [16]) is suitable but provides only
limited service.
If a UE has an ongoing emergency call, all acceptable cells of that PLMN are treated as suitable for cell reselection for
the duration of the emergency call.
5
Process and procedure descriptions
5.1
PLMN selection
5.1.1
General
In the UE, the AS shall report available PLMNs to the NAS on request from the NAS or autonomously.
UE shall maintain a list of allowed PLMN types. The allowed PLMN type can be GSM-MAP only, ANSI-41 only or
both. During PLMN selection, based on the list of allowed PLMN types and a list of PLMN identities in priority order,
the particular PLMN may be selected either automatically or manually. Each PLMN in the list of PLMN identities can
be identified by either 'PLMN identity' (GSM-MAP) or 'SID'. In the system information on the broadcast channel, the
UE can receive a 'PLMN identity' (GSM-MAP) or a 'SID' or a 'PLMN identity' (GSM-MAP) and a 'SID', in a given cell.
For a given cell, the UE might receive several 'PLMN identities' from the system information on the broadcast channel.
The result of the PLMN selection is an identifier of the selected PLMN, the choice being based on the allowed PLMN
types, UE capability or other factors. This identifier is one of either 'PLMN identity' for GSM-MAP type of PLMNs or
'SID' for ANSI-41 type of PLMNs.
In case that the list of allowed PLMN types includes GSM-MAP, the non-access part of the PLMN selection process is
specified in [5]. In the case that list of allowed PLMN types includes ANSI-41, the non-access stratum part of the
PLMN selection is specified in TIA/EIA/IS-2000.5 and TIA/EIA/IS-707.
5.1.2
5.1.2.1
Support for PLMN Selection
General
On request of the NAS the AS should perform a search for available PLMNs and report them to NAS.
5.1.2.2
UTRA case
The UE shall scan all RF channels in the UTRA bands according to its capabilities to find available PLMNs. On each
carrier, the UE shall search for the strongest cell and read its system information, in order to find out which PLMN the
cell belongs to. If the UE can read one or several PLMN identities in the strongest cell, each found PLMN (see the
PLMN reading in [4]) shall be reported to the NAS as a high quality PLMN (but without the RSCP value), provided
that the following high quality criterion is fulfilled:
1. For an FDD cell, the measured primary CPICH RSCP value shall be greater than or equal to -95 dBm.
2. For a TDD cell, the measured P-CCPCH RSCP shall be greater than or equal to -84 dBm.
Found PLMNs that do not satisfy the high quality criterion, but for which the UE has been able to read the PLMN
identities are reported to the NAS together with the CPICH RSCP value for UTRA FDD cells and P-CCPCH RSCP for
UTRA TDD cells. The quality measure reported by the UE to NAS shall be the same for each PLMN found in one cell.
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The search for PLMNs on the rest of the carriers may be stopped on request of the NAS. The UE may optimise this
search by using stored information of carrier frequencies and optionally also information on cell parameters, e.g.
scrambling codes, from previously received measurement control information elements.
Once the UE has selected a PLMN, the cell selection procedure shall be performed in order to select a suitable cell of
that PLMN to camp on.
5.1.2.3
GSM case
Support for network selection in GSM is described in [1].
5.2
Cell selection and reselection in idle mode
5.2.1
Introduction
As stated in clause 1, the present document applies to UEs that support at least UTRA.
Different types of measurements are used in different RATs and modes for the cell selection and reselection. The
performance requirements for the measurements are specified in [10] and [11].
The NAS can control the RAT(s) in which the cell selection should be performed, for instance by indicating RAT(s)
associated with the selected PLMN, and by maintaining a list of forbidden registration area(s) and a list of equivalent
PLMNs. The UE shall select a suitable cell and the radio access mode based on idle mode measurements and cell
selection criteria.
In order to speed up the cell selection process, stored information for several RATs may be available in the UE.
When camped on a cell, the UE shall regularly search for a better cell according to the cell reselection criteria. If a
better cell is found, that cell is selected. The change of cell may imply a change of RAT. Details on performance
requirements for cell reselection can be found in [10] and [11].
The NAS is informed if the cell selection and reselection results in changes in the received system information.
For normal service, the UE has to camp on a suitable cell, tune to that cell's control channel(s) so that the UE can:
-
-
Receive system information from the PLMN;
-
Receive registration area information from the PLMN, e.g., location area and routing area; and
-
Receive other AS and NAS Information;
If registered:
-
receive paging and notification messages from the PLMN; and
-
initiate call setup for outgoing calls or other actions from the UE.
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States and state transitions in Idle Mode
Figure 2 shows the states and procedures in Idle Mode.
go here w henever a
new PLMN is
selected
cell inf ormation
stored f or the PLMN
Stored
information
Cell Se lection
no suitable
cell found
no cell information
stored for the PLMN
1
Init ial
Cell Se lection
no suitable cell found
2
suitable cell found
suitable cell found
no suitable
cell f ound
Cell Se lection
w hen leaving
connected
mode
suitable
cell found
return to
idle mode
leave
idle mode
Connected
mode
Ca mped
normally
NAS indicates that
registration on selected
PL MN is rejected
(except w ith cause
#12, #14 or #15
[5][16])
trigger
suitable
cell found
Cell
Reselection
Evaluation
Process
no suitable
cell found
go here
w hen no
USIM in
the UE
Any Cell
Selection
no acceptable cell f ound
USIM inserted
acceptable
cell found
Cell Se lection
w hen leaving
connected
mode
return to
idle mode
acceptable
cell f ound
leave
idle mode
Connected
mode
(Emergency
calls only)
Camped on
any cell
suitable
cell f ound
1
2
trigger
acceptable
cell found
Cell
Reselection
Evaluation
Process
no acceptable
cell f ound
Figure 2: Idle Mode Cell Selection and Reselection
In any state, a new PLMN selection causes an exit to number 1
5.2.2.1
Cell Selection process overview
Whenever a PLMN has been selected by NAS, the UE shall attempt to find a suitable cell to camp on.
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The NAS may control the cell selection by:
-
providing information on RAT(s) associated with the selected PLMN;
-
maintaining lists of forbidden registration areas;
-
providing a list of equivalent PLMNs;
One or several RATs may be associated with the selected PLMN. In [5] it is specified which RAT a UE shall select to
search for a suitable cell of the selected PLMN.
The AS shall attempt to find a suitable cell to camp on as specified in clause 5.2.3.
When the MBMS frequency layer dispersion is triggered, the UE actions are specified in [4].
If a suitable cell is found, the UE shall select this cell to camp on, and report this event to NAS so that the necessary
NAS registration procedures can be performed. When the registration is successful, the UE enters in state Camped
normally in order to obtain normal service.
If the UE is unable to find any suitable cell of selected PLMN the UE shall enter the Any cell selection state.
5.2.2.2
Camped normally state overview
In this state, the UE obtains normal service and performs the tasks specified in 5.2.5.
If after a Cell reselection evaluation process a better cell is found, the Cell reselection procedure is performed. If no
suitable cell is found, the UE shall enter the state Any cell selection.
If a necessary NAS registration is rejected, the UE shall enter the Any cell selection state, except if the LR is rejected
with cause #12, cause #14 or cause #15. In this case the UE shall behave as specified in [5] and [16].
When UE leaves idle mode in order to enter the state Connected mode, the UE shall attempt to access the current
serving cell. If the access attempt to the serving cell fails, the UE shall use the Cell reselection evaluation procedure.
5.2.2.3
Connected mode State overview
The procedures in Connected mode state are specified in [4]
When returning to idle mode, the UE shall use the procedure Cell selection when leaving connected mode in order to
find a suitable cell to camp on and enter state Camped normally. If a suitable cell is found, then the AS reports this
event to NAS to be capable to perform necessary NAS registration procedures. If no suitable cell is found, the Stored
information cell selection procedure shall be used.
If no suitable cell is found in cell reselection evaluation process, the UE enters the state Any cell selection.
5.2.2.4
Any cell selection State overview
In this state the UE performs the tasks specified in subclause 5.2.8
The state Any cell selection is also entered if the NAS indicates that a location registration is rejected except if the LR is
rejected with cause #12, cause #14 or cause #15, see [5], or if there is no USIM in the UE.
If the UE received an LR reject with cause #12, cause #14 or cause #15, the UE shall behave as specified in [5] and [16].
If an acceptable cell is found, the UE shall inform the NAS and camp on this cell and obtain limited service, state
Camped on any cell. The subsequent actions of the NAS regarding the PLMN selection are specified in [5].
5.2.2.5
Camped on any cell State overview
In this state the UE obtains limited service and shall behave as specified in subclause 5.2.9. The UE shall regularly
attempt to find a suitable cell, trying all RATs that are supported by the UE. If a suitable cell is found, this causes an
exit to number 2 in figure 2.
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3GPP TS 25.304 V6.10.0 (2008-03)
The 'PLMN selection' process may select a new PLMN at any time in idle mode, which in Figure 2 causes
an exit to number 1.
Cell Selection Process
5.2.3.1
UTRA case
5.2.3.1.1
Description
The UE shall use one of the following two search procedures:
a) Initial Cell Selection
This procedure requires no prior knowledge of which RF channels are UTRA carriers. The UE shall scan all
RF channels in the UTRA bands according to its capabilities to find a suitable cell. On each carrier, the UE
need only search for the strongest cell. Once a suitable cell is found this cell shall be selected.
b) Stored Information Cell Selection
This procedure requires stored information of carrier frequencies and optionally also information on cell
parameters, e.g. scrambling codes, from previously received measurement control information elements.
Once the UE has found a suitable cell the UE shall select it. If no suitable cell is found the Initial cell
selection procedure shall be started.
5.2.3.1.2
Criteria
The cell selection criterion S is fulfilled when:
for FDD cells:
Srxlev > 0 AND Squal > 0
for TDD cells:
Srxlev > 0
Where:
Squal = Qqualmeas – Qqualmin
Srxlev = Qrxlevmeas - Qrxlevmin - Pcompensation
Squal
Srxlev
Qqualmeas
Qrxlevmeas
Qqualmin
Qrxlevmin
Pcompensation
UE_TXPWR_MAX_RACH
P_MAX
Cell Selection quality value (dB)
Applicable only for FDD cells.
Cell Selection RX level value (dB)
Measured cell quality value. The quality of the received signal expressed in CPICH Ec/N0
(dB) for FDD cells. CPICH Ec/N0 shall be averaged as specified in [10]. Applicable only
for FDD cells.
Measured cell RX level value. This is received signal, CPICH RSCP for FDD cells (dBm)
and P-CCPCH RSCP for TDD cells (dBm).
Minimum required quality level in the cell (dB). Applicable only for FDD cells.
Minimum required RX level in the cell (dBm)
max(UE_TXPWR_MAX_RACH – P_MAX, 0) (dB)
Maximum TX power level an UE may use when accessing the cell on RACH (read in
system information) (dBm)
Maximum RF output power of the UE (dBm)
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GSM case
The cell selection criteria and procedures in GSM are specified in [1].
5.2.4
Void
5.2.5
Camped Normally State
5.2.5.1
UTRA case
When camped normally, the UE shall perform the following tasks:
-
select and monitor the indicated PICH and PCH of the cell as specified in clause 8 according to information sent
in system information;
-
monitor relevant System Information. This is specified in [4];
-
perform necessary measurements for the cell reselection evaluation procedure;
-
execute the cell reselection evaluation process on the following occasions/triggers:
1) UE internal triggers, so as to meet performance as specified in [10] and [11];
2) When information on the BCCH used for the cell reselection evaluation procedure has been modified
If the UE supports MBMS and MBMS is active in the cell and the UE is permitted to receive MBMS services in the cell,
the UE shall perform MBMS tasks as specified in subclause 6.3.
5.2.5.2
GSM case
The Camped Normally State is specified in [1].
5.2.6
5.2.6.1
Cell Reselection Evaluation Process
UTRA case
The cell reselection process is specified in the following sub-clauses:
5.2.6.1.0
Use of MBMS PL
In the cell reselection process, an MBMS PL shall only be applicable while the UE is receiving an MBMS session from
one or more of the ongoing activated MBMS services for which this PL is indicated.
5.2.6.1.1
Measurement rules for cell re-selection when HCS is not used
The measurement rules below apply in Idle, URA_PCH, CELL_PCH states. In CELL_FACH state the UE is required
to perform measurements on all intra-frequency, inter-frequency and inter-RAT cells listed in system information
according to requirements specified in [10]. In Idle, URA_PCH, CELL_PCH and CELL_FACH states the UE shall only
consider those cells the UE is mandated to measure according to the measurement rules below as measured cells in the
cell reselection criteria (subclause 5.2.6.1.4).
If the system information broadcast in the serving cell indicates that HCS is not used, then for intra-frequency and interfrequency measurements and inter-RAT measurements, the UE shall:
-
use Squal for FDD cells and Srxlev for TDD for Sx, and apply the following rules.
1. If Sx > Sintrasearch, UE may choose to not perform intra-frequency measurements.
If Sx <= Sintrasearch, perform intra-frequency measurements.
If Sintrasearch, is not sent for serving cell, perform intra-frequency measurements.
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2. If Sx > Sintersearch and MBMS PL has not been indicated, and Srxlev > SsearchHCS if SsearchHCS is signalled, UE may
choose to not perform inter-frequency measurements.
If Sx > Sintersearchand MBMS PL has been indicated and the serving cell belongs to the MBMS PL, and Srxlev >
SsearchHCS if SsearchHCS is signalled, UE may choose to not perform inter-frequency measurements.
If Sx > Sintersearch, and MBMS PL has been indicated and the serving cell does not belong to the MBMS PL, and
Srxlev > SsearchHCS if SsearchHCS is signalled, UE shall at least perform inter-frequency measurements on the
MBMS PL.
If Sx <= Sintersearch, or Srxlev <= SsearchHCS if SsearchHCS is signalled, perform inter-frequency measurements.
If Sintersearch, is not sent for serving cell, perform inter-frequency measurements.
3. If Sx > SsearchRAT m, and Srxlev > SHCS,RATm if SHCS,RATm is signalled, UE may choose to not perform
measurements on cells of RAT "m".
If Sx <= SsearchRAT m, or Srxlev <= SHCS,RATm if SHCS,RATm is signalled, perform measurements on cells of RAT
"m".
If SsearchRAT m, is not sent for serving cell, perform measurements on cells of RAT "m".
If HCS is not used and if Slimit,SearchRATm is sent for serving cell, UE shall ignore it.
The presence of SsearchHCS and SHCS,RATm thresholds in system information are used to avoid introducing
new parameters to system information and their presence does not imply that HCS is used.
NOTE:
5.2.6.1.1a
High mobility state when HCS is not used
High-mobility, as applied in HCS case, is also applicable in non-HCS if the parameters non-HCS_ TCRmax, nonHCS_NCR and non-HCS_TCRmaxhyst are sent on the system information broadcast.
If in non-HCS environment the number of cell reselections during time period non-HCS_TCRmax exceeds non-HCS_NCR,
high-mobility state has been detected.
When the number of cell reselections during time period non-HCS_TCRmax no longer exceeds non-HCS_NCR, the UE
shall:
-
continue in high-mobility state.
-
if the criteria for entering high mobility is not detected during time period non-HCS-TCrmaxHyst:
-
exit high-mobility.
If the UE is in non-HCS environment and in high-mobility state, the UE shall apply the speed dependent scaling rules as
defined in subclause 5.2.6.1.4.
5.2.6.1.2
Measurement rules for cell re-selection when HCS is used
The measurement rules below apply in Idle, URA_PCH, CELL_PCH states. In CELL_FACH state the UE is required
to perform measurements on all intra-frequency, inter-frequency and inter-RAT cells listed in system information
according to requirements specified in [10]. In Idle, URA_PCH, CELL_PCH and CELL_FACH states the UE shall only
consider those cells the UE is mandated to measure according to the measurement rules below as measured cells in the
cell reselection criteria (subclause 5.2.6.1.4).
If the system information broadcast in the serving cell indicates that HCS is used, then for intra-frequency and interfrequency measurements, the UE shall:
use HCS priority1 as the HCS priority broadcast in the system information and apply the following rule:
IF an MBMS PL is used THEN
-
If the UE is in HCS low mobility state, for serving cell and neighbour cells belonging to the MBMS PL set
the HCS priority = HCS priority1 + HCS_OFFmbms.
-
If the UE is in HCS high mobility state, for serving cell and neighbour cells belonging to the MBMS PL set
the HCS priority = HCS priority1.
-
for serving cell and neighbour cells not belonging to the MBMS PL, set the HCS priority = HCS priority1.
IF an MBMS PL is not used THEN
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For serving cell and all neighbour cells set HCS priority = HCS priority1
Then apply this to the following:
1. For intra-frequency and inter-frequency measurement rules for UEs not in high-mobility
use Squal for FDD cells and Srxlev for TDD cells for Sx and apply the following rules.
IF (Srxlevs <= SsearchHCS) or (if FDD and Sx <= Sintersearch) THEN
measure on all intra-frequency and inter-frequency cells.
ELSE
IF (Sx > Sintrasearch) THEN
measure on all intra-frequency and inter-frequency cells, which have higher HCS priority level than the
serving cell
ELSE
measure on all intra-frequency and inter-frequency cells, which have equal or higher HCS priority level
than the serving cell
ENDIF
IF (Sintrasearch is not sent for the serving cell) THEN
measure on all intra-frequency cells. Fast-moving UEs may also use this rule.
measure on all inter-frequency cells, which have higher HCS priority level than the serving cell unless
measurement rules for fast-moving UEs are triggered.
ENDIF
ENDIF
If HCS is used and if SsearchHCS or Sintersearch (in FDD) are not sent for the serving cell, UE shall:
-
measure on all intra-frequency and inter-frequency cells.
2. For intra-frequency and inter-frequency measurement rules for fast-moving UEs:
If the number of cell reselections during time period TCRmax exceeds NCR, high-mobility has been detected. In this
high-mobility state, UE shall
-
IF (Srxlevs <= SsearchHCS) or (if FDD and Sx <= Sintersearch), or SsearchHCS or Sintersearch (in FDD) are not sent for the
serving cell THEN
measure on all intra-frequency and inter-frequency cells.
ELSE
-
measure intra-frequency and inter-frequency neighbouring cells, which have equal or lower HCS priority
than serving cell.
ENDIF
When the number of cell reselections during time period TCRmax no longer exceeds NCR, UE shall
-
continue these measurements during time period TCrmaxHyst
-
if the criteria for entering high mobility is not detected during time period TCrmaxHyst:
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exit high-mobility.
When serving cell belongs to a hierarchical cell structure, the UE shall follow these rules for Inter-RAT measurements:
1. Inter-RAT threshold-based measurement rules for UEs not in high-mobility
use Squal for FDD cells and Srxlev for TDD cells for Sx and apply the following rules.
IF (Srxlevs <= SHCS,RATm) or (if FDD and Squal <= SSearchRATm) THEN
UE shall measure on all inter-RATm cells.
ELSE
IF (Sx > Slimit,SearchRATm) THEN
UE may choose to not measure neighbouring cells in RAT "m".
ELSE
UE shall measure on all neighbouring cells in RAT "m", which have equal or higher HCS priority level
than the serving cell
ENDIF
ENDIF
If HCS is used and if SHCS,RATm is not sent for the serving cell, UE shall measure on all inter-RATm cells.
2. Inter-RAT measurement rules for fast-moving UEs
-
If the number of cell reselections during time period TCRmax exceeds NCR, high-mobility has been detected. In
this high-mobility state, UE shall
-
IF (Srxlevs <= SHCS,RATm) or (if FDD and Squal <= SSearchRATm), or SHCS,RATm or SSearchRATm are not sent for the
serving cell THEN
-
UE shall measure on all inter-RATm cells.
ELSE
-
measure the neighbouring cells in RAT "m", which have an equal or lower HCS priority than the serving
cell
ENDIF
When the number of cell reselections during time interval TCRmax no longer exceeds NCR, UE shall
-
continue these measurements during time period TCrmaxHyst
-
if the criteria for entering high mobility is not detected during time period TCrmaxHyst
-
5.2.6.1.3
exit high-mobility.
Highest ranked cells with cell reservations, access restrictions or unsuitable for
normal camping
For the highest ranked cell (including serving cell) according to cell reselection criteria specified in subclause 5.2.6.1.4,
the UE shall check if the access is restricted according to the rules in subclause 5.3.1.1.
If that cell and other cells have to be excluded from the candidate list, as stated in subclause 5.3.1.1, the UE shall not
consider these as candidates for cell reselection. This limitation is removed when the highest ranked cell changes.
If the highest ranked cell is an intra-frequency or inter-frequency cell which is not suitable due to being part of the "list
of forbidden LAs for roaming" or belonging to a PLMN which is not indicated as being equivalent to the registered
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PLMN, the UE shall not consider this cell and other cells on the same frequency, as candidates for reselection for a
maximum of 300s. If the UE has to perform an any cell selection procedure any limitation shall be removed.
If the highest ranked cell is an inter-RAT cell which is not suitable due to being part of the "list of forbidden LAs for
roaming" or belonging to a PLMN which is not indicated as being equivalent to the registered PLMN, the UE shall not
consider this cell as a candidate for reselection for a maximum of 300s. If the UE has to perform an any cell selection
procedure any limitation shall be removed.
5.2.6.1.4
Cell Reselection Criteria
The following cell re-selection criteria are used for intra-frequency cells, inter-frequency cells and inter-RAT cells:
The quality level threshold criterion H for hierarchical cell structures is used to determine whether prioritised ranking
according to hierarchical cell re-selection rules shall apply, and is defined by:
Hs = Qmeas,s - Qhcss
Hn = Qmeas,n - Qhcsn – TOn * Ln
If it is indicated in system information that HCS is not used, the quality level threshold criterion H is not applied.
The cell-ranking criterion R is defined by:
Rs = Qmeas,s + Qhysts + Qoffmbms
Rn = Qmeas,n - Qoffsets,n + Qoffmbms - TOn * (1 – Ln)
where:
the signalled value Qoffmbms is only applied to those cells (serving or neighbouring) belonging to the MBMS PL
where:
TOn = TEMP_OFFSETn * W(PENALTY_TIMEn – Tn)
Ln = 0
Ln = 1
if HCS_PRIOn = HCS_PRIOs
if HCS_PRIOn <> HCS_PRIOs
W(x) = 0
W(x) = 1
for x < 0
for x >= 0
TEMP_OFFSETn applies an offset to the H and R criteria for the duration of PENALTY_TIMEn after a timer Tn has
started for that neighbouring cell.
TEMP_OFFSETn and PENALTY_TIMEn are only applicable if the usage of HCS is indicated in system information.
The timer Tn is implemented for each neighbouring cell. Tn shall be started from zero when one of the following
conditions becomes true:
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if HCS_PRIOn <> HCS_PRIOs and
Qmeas,n >= Qhcsn
Or
-
if HCS_PRIOn = HCS_PRIOs and
-
for serving FDD and neighbour FDD cells if the quality measure for cell selection and reselection is set to
CPICH RSCP in the serving cell, and:
Qmeas,n > Qmeas,s + Qoffset1s,n
-
for serving FDD and neighbour FDD cells if the quality measure for cell selection and reselection is set to
CPICH Ec/No in the serving cell, and:
Qmeas,n > Qmeas,s + Qoffset2s,n
-
for all other serving and neighbour cells:
Qmeas,n > Qmeas,s + Qoffset1s,n
Tn for the associated neighbour cell shall be stopped as soon as any of the above conditions are no longer fulfilled. Any
value calculated for TOn is valid only if the associated timer Tn is still running else TOn shall be set to zero.
At cell-reselection, a timer Tn is stopped only if the corresponding cell is not a neighbour cell of the new serving cell, or
if the criteria given above for starting timer Tn for the corresponding cell is no longer fulfilled with the parameters of
the new serving cell. On cell re-selection, timer Tn shall be continued to be run for the corresponding cells but the
criteria given above shall be evaluated with parameters broadcast in the new serving cell if the corresponding cells are
neighbours of the new serving cell.
Sn
Qmeas
Cell Selection value of the neighbouring cell, (dB)
Quality value. The quality value of the received signal derived from the averaged CPICH
Ec/No or CPICH RSCP for FDD cells, from the averaged P-CCPCH RSCP for TDD cells
and from the averaged received signal level for GSM cells. The averaging of these
measurement quantities are performed as specified in [10] and [11]. For FDD cells, the
measurement that is used to derive the quality value is set by the
Cell_selection_and_reselection_quality_measure information element.
Cell reselection parameters broadcast in system information are listed in subclause 5.2.6.1.5.
The cell selection criterion S used for cell reselection is fulfilled when:
for FDD cells:
Srxlev > 0 AND Squal > 0
for TDD cells:
Srxlev > 0
for GSM cells:
Srxlev > 0
Where :
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Squal = Qqualmeas – Qqualmin
Srxlev = Qrxlevmeas - Qrxlevmin - Pcompensation
Squal
Srxlev
Qqualmeas
Qrxlevmeas
Qqualmin
Qrxlevmin
Pcompensation
UE_TXPWR_MAX_RACH
P_MAX
Cell Selection quality value (dB)
Applicable only for FDD cells.
Cell Selection RX level value (dB)
Measured cell quality value. The quality of the received signal expressed in CPICH Ec/N0
(dB) for FDD cells. CPICH Ec/N0 shall be averaged as specified in [10].
Applicable only for FDD cells.
Measured cell RX level value. This is received signal, CPICH RSCP for FDD cells (dBm),
P-CCPCH RSCP for TDD cells (dBm) and the averaged received signal level as
specified in [10] for GSM cells (dBm). CPICH RSCP, P-CCPCH RSCP and the received
signal level for GSM cells shall be averaged as specified in [10] and [11].
Minimum required quality level in the cell (dB). Applicable only for FDD cells.
Minimum required RX level in the cell (dBm)
max(UE_TXPWR_MAX_RACH – P_MAX, 0) (dB)
Maximum TX power level an UE may use when accessing the cell on RACH (read in
system information) (dBm)
Maximum RF output power of the UE (dBm)
If HCS is not used in the serving cell the UE shall perform ranking of all cells that fulfil the criterion S, among:
-
all measured cells (see subclause 5.2.6.1.1).
If HCS is used in the serving cell the UE shall perform ranking of all cells that fulfil the criterion S among
1. when in low-mobility (see subclause 5.2.6.1.2),
-
all measured cells, that have the highest HCS_PRIO among those cells that fulfil the criterion H >= 0.
-
all measured cells, not considering HCS priority levels, if no cell fulfil the criterion H >= 0.
2 when in high-mobility (see subclause 5.2.6.1.2),
-
all measured cells, and among these cells:
-
if there are cells with a lower HCS priority than the serving cell that fulfil the criterion H >= 0:
-
-
from the cells that have a lower HCS priority than the serving cell, all cells that have the highest
HCS_PRIO among those cells that fulfil the criterion H >=0;
else:
-
if there are cells that fulfil the criterion H >= 0 with an HCS priority higher or equal to the HCS
priority of the serving cell:
-
-
from the cells that have an HCS priority higher or equal to the HCS priority of the serving cell, all
cells that have the lowest HCS_PRIO among those cells that fulfil the criterion H >=0;
else
-
all cells not considering HCS priority levels.
The cells shall be ranked according to the R criteria specified above, deriving Qmeas,n and Qmeas,s and calculating the R
values using CPICH RSCP, P-CCPCH RSCP and the averaged received signal level as specified in [10] and [11] for
FDD, TDD and GSM cells, respectively.
The offset Qoffset1s,n is used for Qoffsets,n to calculate Rn, the hysteresis Qhyst1s is used for Qhysts to calculate Rs. For
UE in RRC connected mode states CELL_PCH or URA_PCH the hysteresis Qhysts takes the value Qhyst1s,PCH to
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calculate Rs, if provided in SIB4 [see 4]. For UE in RRC connected mode state CELL_FACH the hysteresis Qhysts
takes the value Qhyst1s,FACH to calculate Rs, if provided in SIB4 [see 4].
If the usage of HCS is indicated in system information, TEMP_OFFSET1n is used for TEMP_OFFSETn to calculate
TOn. If it is indicated in system information that HCS is not used, TEMP_OFFSETn is not applied when calculating Rn.
The best ranked cell is the cell with the highest R value.
If a TDD or GSM cell is ranked as the best cell, then the UE shall perform cell re-selection to that TDD or GSM cell.
If an FDD cell is ranked as the best cell and the quality measure for cell selection and re-selection is set to CPICH
RSCP, the UE shall perform cell re-selection to that FDD cell. If this cell is found to be not suitable, the UE shall
behave according to subclause 5.2.6.1.3.
If an FDD cell is ranked as the best cell and the quality measure for cell selection and re-selection is set to CPICH
Ec/No, the UE shall perform a second ranking of the FDD cells according to the R criteria specified above, but using
the measurement quantity CPICH Ec/No for deriving the Qmeas,n and Qmeas,s and calculating the R values of the FDD
cells. The offset Qoffset2s,n is used for Qoffsets,n to calculate Rn, the hysteresis Qhyst2s is used for Qhysts to calculate Rs.
For UE in RRC connected mode states CELL_PCH or URA_PCH the hysteresis Qhysts takes the value Qhyst2s,PCH to
calculate Rs, if provided in SIB4 [see 4]. For UE in RRC connected mode state CELL_FACH the hysteresis Qhysts
takes the value Qhyst2s,FACH to calculate Rs, if provided in SIB4 [see 4]. If the usage of HCS is indicated in system
information, TEMP_OFFSET2n is used to calculate TOn. If it is indicated in system information that HCS is not used,
TEMP_OFFSETn is not applied when calculating Rn. Following this second ranking, the UE shall perform cell reselection to the best ranked FDD cell. If this cell is found to be not suitable, the UE shall behave according to subclause
5.2.6.1.3.
In all cases, the UE shall reselect the new cell, only if the following conditions are met:
-
the new cell is better ranked than the serving cell during a time interval Treselection. For UE in RRC connected
mode states CELL_PCH or URA_PCH the interval Treselections,PCH applies, if provided in SIB4 [see 4], while
for UE in RRC connected mode state CELL_FACH the interval Treselections,FACH applies, if provided in SIB4
[see 4]. For hierarchical cell structures when high mobility state has not been detected, if according to the HCS
rules the serving cell is not ranked then all the ranked cells are considered to be better ranked than the serving
cell. In case the UE reselects to a cell on an MBMS preferred frequency to receive an MBMS service not
available on the current frequency the UE may reduce interval TreselectionS, TreselectionS, PCH and TreselectionS,
FACH.
Additionally the UE shall apply the following scaling rules to Treselections or Treselections,PCH or
Treselections,FACH:
-
For intra-frequency cells and high mobility state not detected:
-
-
For intra-frequency cells and high mobility state is detected:
-
-
multiply Treselections or Treselections,PCH or Treselections,FACH by both the IEs "Speed dependent
ScalingFactor for_Treselection" if sent on system information and "Inter-Frequency ScalingFactor for
Treselection" if sent on system information.
For inter-RAT cells and high mobility state not detected:
-
-
multiply Treselections or Treselections,PCH or Treselections,FACH by the IE "Inter-Frequency ScalingFactor
for Treselection" if sent on system information.
For inter-frequency cells and high mobility state is detected:
-
-
multiply Treselections or Treselections,PCH or Treselections,FACH by the IE "Speed dependent ScalingFactor
for_Treselection" if sent on system information.
For inter-frequency cells and high mobility state not detected:
-
-
no scaling applied.
multiply Treselections or Treselections,PCH or Treselections,FACH by the IE "Inter-RAT ScalingFactor for
Treselection" if sent on system information.
For inter-RAT cells and high mobility state is detected:
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multiply Treselections or Treselections,PCH or Treselections,FACH by both the IEs “Speed dependent
ScalingFactor for_Treselection” if sent on system information and “Inter-RAT ScalingFactor for
Treselection" if sent on system information.
In case scaling is applied to Treselections or Treselections,PCH, the UE shall round up the result after all scalings
to the nearest second. In case scaling is applied to Treselections,FACH, the UE shall round up the result after all
scalings to the nearest 0.2 seconds.
-
more than 1 second has elapsed since the UE camped on the current serving cell.
5.2.6.1.5
Cell reselection parameters in system information broadcasts
The selection of values for network controlled parameters can be optimised by means of different methods. Examples of
methods are described in [6]. Cell reselection parameters are broadcast in system information and are read in the serving
cell as follows:
Qoffset1s,n
This specifies the offset between the two cells. It is used for TDD and GSM cells and for FDD cells in case the quality
measure for cell selection and re-selection is set to CPICH RSCP.
Qoffset2s,n
This specifies the offset between the two cells. It is used for FDD cells in case the quality measure for cell selection and
re-selection is set to CPICH Ec/No.
Qhyst1s
This specifies the hysteresis value (Qhyst). It is used for TDD and GSM cells and for FDD cells in case the quality
measure for cell selection and re-selection is set to CPICH RSCP.
Qhyst1s,PCH
This specifies the hysteresis value (Qhyst) to be used in RRC connected mode states CELL_PCH and URA_PCH. It is
used for TDD and GSM cells and for FDD cells in case the quality measure for cell selection and re-selection is set to
CPICH RSCP. If this parameter is not provided in SIB4, Qhyst1s shall be used.
Qhyst1s,FACH
This specifies the hysteresis value (Qhyst) to be used in RRC connected mode state CELL_FACH. It is used for TDD
and GSM cells and for FDD cells in case the quality measure for cell selection and re-selection is set to CPICH RSCP.
If this parameter is not provided in SIB4, Qhyst1s shall be used.
Qhyst2s
This specifies the hysteresis value (Qhyst). It is used for FDD cells if the quality measure for cell selection and reselection is set to CPICH Ec/No.
Qhyst2s,PCH
This specifies the hysteresis value (Qhyst) to be used in RRC connected mode states CELL_PCH and URA_PCH. It is
used for FDD cells if the quality measure for cell selection and re-selection is set to CPICH Ec/No. If this parameter is
not provided in SIB4, Qhyst2s shall be used.
Qhyst2s,FACH
This specifies the hysteresis value (Qhyst) to be used in RRC connected mode state CELL_FACH. It is used for FDD
cells if the quality measure for cell selection and re-selection is set to CPICH Ec/No. If this parameter is not provided in
SIB4, Qhyst2s shall be used.
HCS_PRIOs, HCS_PRIOn
This specifies the HCS priority level (0-7) for serving cell and neighbouring cells.
HCS priority level 0 means lowest priority and HCS priority level 7 means highest priority.
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HCS_OFFmbms
This specifies the offset to the normal HCS priority level that is used for cells belonging to the MBMS PL.
Qhcss, Qhcsn
This specifies the quality threshold levels for applying prioritised hierarchical cell re-selection.
Qoffmbms
This specifies the additional offset added to cells belonging to the MBMS PL.
Qqualmin
This specifies the minimum required quality level in the cell in dB. It is not applicable for TDD cells or GSM cells.
Qrxlevmin
This specifies the minimum required RX level in the cell in dBm.
PENALTY_TIMEn
This specifies the time duration for which the TEMPORARY_OFFSETn is applied for a neighbouring cell.
TEMPORARY_OFFSET1n
This specifies the offset applied to the H and R criteria for a neighbouring cell for the duration of PENALTY_TIMEn. It
is used for TDD and GSM cells and for FDD cells in case the quality measure for cell selection and re-selection is set to
CPICH RSCP.
TEMPORARY_OFFSET2n
This specifies the offset applied to the H and R criteria for a neighbouring cell for the duration of PENALTY_TIMEn. It
is used for FDD cells in case the quality measure for cell selection and re-selection is set to CPICH Ec/No.
TCRmax
This specifies the duration for evaluating allowed amount of cell reselection(s).
NCR
This specifies the maximum number of cell reselections.
TCRmaxHyst
This specifies the additional time period before the UE can exit high-mobility.
non-HCS_TCRmax
This specifies the duration for evaluating allowed amount of cell reselection(s) in case of non-HCS usage.
non-HCS_NCR
This specifies the maximum number of cell reselections in case of non-HCS usage.
non-HCS_TCRmaxHyst
This specifies the additional time period before the UE can revert to low-mobility measurements in case of non-HCS
usage.
Treselections
This specifies the cell reselection timer value.
Treselections,PCH
This specifies the cell reselection timer value the UE shall use in RRC connected mode states CELL_PCH and
URA_PCH if provided in SIB4, otherwise Treselections shall be used.
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Treselections,FACH
This specifies the cell reselection timer value the UE shall use in RRC connected mode state CELL_FACH if provided
in SIB4, otherwise Treselections shall be used.
SsearchHCS
This threshold is used in the measurement rules for cell re-selection. When HCS is used, it specifies the limit for Srxlev
in the serving cell below which the UE shall initiate measurements of all neighbouring cells of the serving cell. When
HCS is not used, it specifies the limit for Srxlev in the serving cell below which the UE ranks inter-frequency
neighbouring cells of the serving cell.
SsearchRAT 1 - SsearchRAT k
This specifies the RAT specific threshold in the serving cell used in the inter-RAT measurement rules.
SHCS,RATm
This threshold is used in the measurement rules for cell re-selection. When HCS is used, it specifies the RAT specific
threshold in the serving cell used in the inter-RAT measurement rules. When HCS is not used, it specifies the limit for
Srxlev in the serving cell below which the UE ranks inter-RAT neighbouring cells of the serving cell.
Sintrasearch
This specifies the threshold (in dB) for intra frequency measurements and for the HCS measurement rules.
Sintersearch
This specifies the threshold (in dB) for inter-frequency measurements and for the HCS measurement rules.
Slimit,SearchRATm
This threshold is used in the measurement rules for cell re-selection when HCS is used. It specifies the RAT specific
threshold (in dB) in the serving UTRA cell above which the UE may choose to not perform any inter-RAT
measurements in RAT "m".
Speed dependent ScalingFactor for Treselection
This specifies the scaling (multiplication) factor to be used by the UE in idle mode or RRC connected mode states for
the parameters Treselections or Treselections,PCH or Treselections,FACH in case high-mobility state has been detected.
Inter-frequency ScalingFactor for Treselection
This specifies the scaling (multiplication) factor to be used by the UE for scaling the parameters Treselections or
Treselections,PCH or Treselections,FACH for the inter-frequency case.
Inter-RAT ScalingFactor for Treselection
This specifies the scaling (multiplication) factor to be used by the UE for scaling the parameters Treselections or
Treselections,PCH or Treselections,FACH for the inter-RAT case.
5.2.6.2
GSM case
The cell reselection procedure in GSM, including reselection from GSM to UTRA, is specified in [1].
5.2.7
5.2.7.1
Cell Selection when leaving connected mode
UTRA case
When returning to idle mode from connected mode, the UE shall select a suitable cell to camp on. Candidate cells for
this selection are the cell(s) used immediately before leaving connected mode. If no suitable cell is found, the UE shall
use the Stored information cell selection procedure in order to find a suitable cell to camp on.
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When returning to idle mode after an emergency call on any PLMN, the UE shall select an acceptable cell to camp on.
Candidate cells for this selection are the cell(s) used immediately before leaving connected mode. If no acceptable cell
is found, the UE shall continue to search for an acceptable cell of any PLMN in state Any cell selection.
5.2.7.2
GSM case
Cell selection when leaving connected mode in GSM is specified in [1].
5.2.8
Any Cell Selection state
In this state, the UE shall attempt to find an acceptable cell of an any PLMN to camp on, trying all RATs that are
supported by the UE and searching first for a high quality cell, as defined in subclause 5.1.2.2.
The UE, which is not camped on any cell, shall stay in this state until an acceptable cell is found.
5.2.9
Camped on Any Cell State
5.2.9.1
UTRA case
In this state, the UE shall perform the following tasks:
-
select and monitor the indicated PICH and PCH of the cell as specified in clause 8;
-
monitor relevant System Information; This is specified in [4];
-
perform necessary measurements for the cell reselection evaluation procedure;
-
Execute the cell reselection evaluation process on the following occasions/triggers:
1) UE internal triggers, so as to meet performance as specified in [10] and [11];
2) When information on the BCCH used for the cell reselection evaluation procedure has been modified;
-
regularly attempt to find a suitable cell trying all RATs that are supported by the UE. If a suitable cell is found,
this causes an exit to number 2 in Figure 2.
In this state the UE is not permitted to receive any MBMS services.
5.2.9.2
GSM case
The camped on any cell state in GSM is specified in [1].
5.3
Cell Reservations and Access Restrictions
5.3.1
UTRA cells
There are two mechanisms which allow an operator to impose cell reservations or access restrictions. The first
mechanism uses indication of cell status and special reservations for control of cell selection and re-selection
procedures. The second mechanism, referred to as Access Control, shall allow to prevent selected classes of users from
sending initial access messages for load control reasons. At subscription, one or more Access Classes are allocated to
the subscriber and stored in the USIM [9], which are employed for this purpose.
5.3.1.1
Cell status and cell reservations
Cell status and cell reservations are indicated with the Cell Access Restriction Information Element in the System
Information Message [4] by means of three Information Elements:
-
Cell barred (IE type: "barred" or "not barred"),
-
Cell Reserved for operator use (IE type: "reserved" or "not reserved"),
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Cell reserved for future extension (IE type: "reserved" or "not reserved").
When cell status is indicated as "not barred", "not reserved" for operator use and "not reserved" for future extension
(Cell Reservation Extension),
-
All UEs shall treat this cell as candidate during the cell selection and cell re-selection procedures in Idle mode
and in Connected mode.
When cell status is indicated as "not barred", "not reserved" for operator use and "reserved" for future extension (Cell
Reservation Extension),
-
UEs shall behave as if cell status "barred" is indicated using the value "not allowed" in the IE "Intra-frequency
cell re-selection indicator" and the maximum value for Tbarred, see [4] (see also below).
When cell status is indicated as "not barred" and "reserved" for operator use,
-
UEs assigned to Access Class 11 or 15 shall treat this cell as candidate during the cell selection and cell reselection procedures in Idle mode and in Connected mode if the cell belongs to the home PLMN.
-
UEs assigned to an Access Class in the range 0 to 9 and 12 to 14 shall behave as if cell status "barred" is
indicated using the value "not allowed" in the IE "Intra-frequency cell re-selection indicator" and the maximum
value for Tbarred, see [4] (see also below).
When cell status "barred" is indicated,
-
The UE is not permitted to select/re-select this cell, not even for emergency calls.
-
The UE shall ignore the "Cell Reserved for future extension (Cell Reservation Extension) use" IE.
-
The UE is not permitted to receive any MBMS services.
-
The UE shall select another cell according to the following rule:
-
-
If the "Intra-frequency cell re-selection indicator" IE in Cell Access Restriction IE is set to value "allowed",
the UE may select another cell on the same frequency if selection/re-selection criteria are fulfilled.
-
If the UE is camping on another cell, the UE shall exclude the barred cell from the neighbouring cell list
until the expiry of a time interval Tbarred. The time interval Tbarred is sent via system information in a barred
cell together with Cell status information in the Cell Access Restriction IE.
-
If the UE does not select another cell, and the barred cell remains to be the "best" one, the UE shall after
expiry of the time interval Tbarred again check whether the status of the barred cell has changed.
If the "Intra-frequency cell re-selection indicator" IE is set to "not allowed" the UE shall not re-select a cell
on the same frequency as the barred cell. During an ongoing emergency call, the Intra-frequency cell reselection indicator IE" shall be ignored, i.e. even if it is set to "not allowed" the UE may select another intrafrequency cell.
-
If the barred cell remains to be the "best" one, the UE shall after expiry of the time interval Tbarred again
check whether the status of the barred cell has changed.
The reselection to another cell may also include a change of RAT.
5.3.1.2
Access Control
Information on cell access restrictions associated with the Access Classes is broadcast as system information, [4].
The UE shall ignore Access Class related cell access restrictions when selecting a cell to camp on, i.e. it shall not reject
a cell for camping on because access on that cell is not allowed for any of the Access Classes of the UE. A change of
the indicated access restriction shall not trigger cell re-selection by the UE.
Access Class related cell access restrictions shall be checked by the UE before sending an RRC CONNECTION
REQUEST message when entering Connected Mode from UTRAN Idle mode. Access Class related cell access
restrictions, if it is sent as a part of Domain Specific Access Restriction parameters, shall also be checked by the UE
before sending INITIAL DIRECT TRANSFER message. Otherwise, cell access restrictions associated with the Access
Classes shall not apply for a UE which already is in Connected Mode.
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Emergency Call
A restriction on emergency calls, if needed, shall be indicated in the "Access class barred list" IE [4]. If access class 10
is indicated as barred in a cell, UEs with access class 0 to 9 or without an IMSI are not allowed to initiate emergency
calls in this cell. For UEs with access classes 11 to 15, emergency calls are not allowed if both access class 10 and the
relevant access class (11 to 15) are barred. Otherwise, emergency calls are allowed for those UEs.
Full details of operation under "Access class barred list" are described in [9].
5.3.2
GSM cells
The cell access restrictions applicable to GSM are specified in [1].
5.4
Cell Selection and Reselection Processes in RRC
Connected Mode
5.4.1
Void
5.4.2
Void
5.4.3
Cell Reselection Process in RRC connected mode
The cell reselection process in Connected Mode is the same as cell reselection evaluation process used for idle mode,
described in subclause 5.2.6.
5.4.4
Cell Selection Process in RRC connected mode
The cell selection process in Connected Mode is for ‘out of service’ conditions [4] is the same as the cell selection
process used for idle mode, described in subclause 5.2.3.
Selection of a suitable cell during a state transition or a change of frequency in Connected Mode is the same as the
selection of a suitable UTRA cell used for idle mode, described in subclause 5.2.3.1. If the UE is ordered to select a
suitable UTRA cell on a given frequency, it shall attempt to select a suitable cell on that frequency before considering
cells on other frequencies.
5.5
Location Registration
In the UE, the AS shall report registration area information to the NAS.
If the UE reads more than one PLMN identity in the current cell, the UE shall report the found PLMN identities that
make the cell suitable in the registration area information to NAS.
The non-access part of the location registration process is specified in [5].
Actions for the UE AS upon reception of Location Registration reject are specified in [9] and [16].
6
Broadcast information receiving
6.1
Reception of System Information
Requirements are specified in [4].
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Cell Broadcast in Idle Mode, CELL_PCH and URA_PCH
A UE supporting Cell Broadcast Service (CBS) shall be capable to receive BMC messages in the Idle mode, in
URA_PCH and CELL_PCH. When several PCHs exist in the cell, the FACH which carries the CTCH may be mapped
to a different SCCPCH than the PCH selected by the UE for paging in Idle mode (as specified in Sec. 8.1). In this case,
UEs with basic service capabilities shall be capable to change from the SCCPCH that carries the PCH selected for
paging to another SCCPCH which carries Cell Broadcast messages (i.e. the CTCH mapped to an FACH) and receive
BMC messages during time intervals which do not conflict with the UE specific paging occasions.
NOTE:
6.3
In case certain BMC messages conflict with the UE specific paging occasions the reception of CBS
cannot be guaranteed and depends on UE capabilities.
MBMS Services
If the UE has activated MBMS services and MBMS is available in the cell (i.e., the MCCH information is provided on
the BCCH) and the UE is permitted to receive MBMS in the cell, the UE shall:
-
receive the MCCH as specified in clause 8.4 and in [4];
-
participate in MBMS counting as specified in [4];
-
receive each FACH on which the MTCH carrying an MBMS activated service that does not require the
establishment of an RRC connection is mapped.
The UE may:
-
monitor the MICH as specified in clause 8a and in [4];
-
receive the MSCH.
7
Void
8
Paging and SCCPCH selection
8.1
Paging Channel selection
System information block type 5 (SIB 5) defines common channels to be employed in Idle mode [4]. In a cell, a single
or several PCHs may be established. Each Secondary Common Control Physical Channel (SCCPCH) indicated to the
UE in system information may carry up to one PCH. Thus, for each defined PCH there is one uniquely associated PICH
also indicated.
In case that more than a single PCH and associated PICH are defined in SIB 5, the UE shall perform a selection
according to the following rule:
-
The UE shall select a SCCPCH from the ones listed in SIB 5 based on IMSI as follows:
"Index of selected SCCPCH" = IMSI mod K,
where K is equal to the number of listed SCCPCHs which carry a PCH (i.e. SCCPCHs carrying FACH only
shall not be counted). These SCCPCHs shall be indexed in the order of their occurrence in SIB 5 from 0 to
K-1.
For GSM-MAP, i.e. "IMSI (GSM-MAP)" is given as sequence of digits of type Integer(0..9), IMSI shall in
the formula above be interpreted as a decimal integer number, where the first digit given in the sequence
represents the highest order digit.
For DS-41, i.e. "IMSI (DS-41)" is given as octet string, IMSI shall in the formulae above correspond to the
decoded decimal representation of the IMSI-S part included in the octet string (see TIA/EIA/IS-2000-5).
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For example:
IMSI (GSM-MAP) = 12 (digit1=1, digit2=2)
In the calculations, this shall be interpreted as the decimal integer "12", not "1x16+2 = 18".
"Index of selected SCCPCH" identifies the selected SCCPCH with the PCH and the uniquely associated PICH to be
used by the UE.
If the UE has no IMSI, for instance when making an emergency call without USIM, the UE shall use as default number
IMSI = 0.
8.2
SCCPCH selection when entering Connected mode
When entering Connected mode from Idle mode by sending an RRC CONNECTION REQUEST message, the UE shall
select the S-CCPCH which carries an FACH to be used for reception of the RRC CONNECTION SETUP message
according to the following rule:
-
the UE shall select an SCCPCH from the SCCPCHs listed in System Information Block type 5 (SIB 5) based on
"Initial UE Identity" as follows:
"Index of selected SCCPCH" = "Initial UE Identity" mod K,
where K is equal to the number of listed SCCPCHs which carry a FACH (i.e. SCCPCHs carrying PCH only
shall not be counted). These SCCPCHs shall be indexed from 0 to K-1 in the order of their occurrence in SIB
5, and "Index of selected SCCPCH" identifies the selected SCCPCH. "Initial UE Identity" refers to the
Information Element included by the UE into the RRC CONNECTION REQUEST message. In the above
formula, the parameter "Initial UE Identity" shall be interpreted as follows, depending on the choice of UE-Id
type of the respective IE:
For UE-Id type "IMSI (GSM-MAP)", i.e. the IE is given as sequence of digits of type Integer(0..9), "Initial
UE Identity" shall be interpreted as an integer number, where the first digit given in the sequence represents
the highest order digit.
For UE-Id types "TMSI and LAI (GSM-MAP)" or "P-TMSI and RAI (GSM-MAP)", only the TMSI or PTMSI parts given as Bitstring(32) shall be used, and "Initial UE Identity" shall be interpreted as a binary
representation of an integer number, where the first bit in the Bitstring represents the highest order bit.
For UE-Id type "IMEI", i.e. the IE is given as sequence of hexadecimal digits of type Integer(0..15), "Initial
UE Identity" shall be interpreted as a hexadecimal representation of an integer number, where the first digit
given in the sequence represents the highest order digit.
For UE-Id type "IMSI (DS-41)", i.e. the IE is given as octet string, "Initial UE Identity" shall correspond to
the decoded decimal representation of the IMSI-S part included in the octet string (see TIA/EIA/IS-2000-5).
For UE-Id types "ESN (DS-41)" or "TMSI (DS-41)", i.e. the IE is given as Bitstring(32), "Initial UE
Identity" shall be interpreted as a binary representation of an integer number, where the first bit in the
Bitstring represents the highest order bit.
For UE-Id type "IMSI and ESN (DS-41)" only the ESN part shall be used as "Initial UE Identity", as defined
above.
8.3
Discontinuous Reception for Paging
The UE may use Discontinuous Reception (DRX) in idle mode in order to reduce power consumption. When DRX is
used the UE needs only to monitor one Page Indicator, PI, (see definition in [7] and [8]) in one Paging Occasion per
DRX cycle.
The DRX cycle length shall be MAX(2k, PBP) frames, where k is an integer and PBP is the Paging Block Periodicity.
PBP is only applicable for TDD and is equal to the PICH repetition period that is broadcast in system information. For
FDD, PBP=1.
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The UE may be attached to different CN domains with different CN domain specific DRX cycle lengths. The UE shall
store each CN domain specific DRX cycle length for each CN domain the UE is attached to and use the shortest of
those DRX cycle lengths. The CS CN specific DRX cycle length coefficient shall be updated locally in the UE using
information given in system information. On the other hand, the PS CN specific DRX cycle length coefficient shall be
updated after the negotiation between the UE and PS CN by NAS procedure. If no specific value "k" is negotiated in
NAS procedure, the UE and PS CN shall use the DRX cycle length given for PS CN domain in system information.
The DRX cycle lengths to use for UTRAN connected mode is the shortest of the following:
-
UTRAN DRX cycle length;
-
any of the stored CN domain specific DRX cycle length for the CN domains the UE is only attached to with no
signalling connection established.
The UE shall use the IMSI, the number of available SCCPCH which carry a PCH (K) as derived according to subclause
8.1,the Cell System Frame Number (SFN), Np (for FDD, Np is the number of page indicators within a frame; for TDD,
Np is the number of page indicators within a paging block), Frame offset (For FDD, Frame offset = 0; for TDD, PICH
frame offset values are given in system information), PBP and the DRX cycle length to determine the Paging Occasions.
In FDD the UE shall monitor its paging indicator in the PICH frame with SFN given by the Paging Occasion
In TDD the UE shall monitor its paging indicator in the paging block given by the Paging Occasion. The Paging
Occasion gives the SFN of the first frame of the paging block.
The value of the Paging Occasion is determined as follows:
Paging Occasion= {(IMSI div K) mod (DRX cycle length div PBP)} * PBP + n * DRX cycle length + Frame
Offset
Where n = 0,1,2… as long as SFN is below its maximum value.
The actual Page Indicator within a Paging Occasion that the UE shall read is similarly determined based on IMSI.
The Page Indicator to use is calculated by using the following formula:
PI =
DRX Index mod Np
where DRX Index = IMSI div 8192
In FDD mode, Np = (18,36,72,144) is the number of Page Indicators per frame, and is given in IE "Number of PI per
frame", part of system information in FDD mode. In TDD mode, Np is the number of Page Indicators per paging block
and is calculated by the Paging Indicator Length LPI, the Burst Type (long or short midamble for 3.84 Mcps TDD) and
the PICH repetition length, which are given in system information.
If the UE has no IMSI, for instance when making an emergency call without USIM, the UE shall use as default numbers,
IMSI = 0 and DRX cycle length = 256 (2.56 s), in the formulas above.
For FDD, see [7] for details about the timing between a PICH frame and when the paging message is transmitted on the
PCH in the associated S-CCPCH frame.
In TDD mode, the Paging Message Receiving Occasion is calculated using the following formula:
Paging Message Receiving Occasion =Paging Occasion + NPICH + NGAP + {(DRX Index mod Np) mod NPCH } *2
The value NPICH is the number of frames for PICH transmission and is equal to the PICH repetition length given in
system information. The value NGAP is the number of frames between the last frame carrying PICH for this Paging
Occasion and the first frame carrying paging messages for this Paging Occasion. The value NPCH is the number of
Paging Groups. NPCH and NGAP are given in system information.
For GSM-MAP, i.e. "IMSI (GSM-MAP)" is given as sequence of digits of type Integer(0..9), IMSI shall in the formulae
above be interpreted as a decimal integer number, where the first digit given in the sequence represents the highest
order digit.
For DS-41, i.e. "IMSI (DS-41)" is given as octet string, IMSI shall in the formulae above correspond to the decoded
decimal representation of the IMSI-S part included in the octet string (see TIA/EIA/IS-2000-5).
3GPP
Release 6
36
3GPP TS 25.304 V6.10.0 (2008-03)
For example:
IMSI (GSM-MAP) = 12 (digit1=1, digit2=2)
In the calculations, this shall be interpreted as the decimal integer "12", not "1x16+2 = 18".
8.4
Discontinuous Reception for MBMS
The UE may use discontinuous reception (DRX) on MBMS channels (MCCH, MSCH, MTCH) to reduce power
consumption while subscribed to MBMS services.
8.4.1 Discontinuous Reception for MCCH
The UE may operate DRX on the MCCH either by monitoring the MICH to determine when it needs to receive the
MCCH or by using the MODIFIED SERVICES INFORMATION message on the MCCH to determine that it does not
need to acquire the remainder of the MCCH information.
The timing of the MCCH information transmission and the need to receive the MCCH are described in detail in [4].
8.4.1.1
Discontinuous Reception via MICH
When the UE operates DRX on the MCCH through monitoring the MICH, the UE needs to monitor one Notification
Indicator (NI), as defined in [7], [8], for each MBMS service it is subscribed to. For each service, a corresponding NI
will be set continuously through the entire length of the modification period preceding a change in the associated
MCCH information. The modification period should be long enough that a UE that only receives the MICH during its
paging occasions can still reliably detect a notification.
For each service, the 16 bit Notification Indicator to use is calculated as a function of the TMGI:
NI = (TMGI + ⎣TMGI / G ⎦) mod G , where G = 216.
A UE with one or more activated MBMS services may monitor the MICH. The exact timing with which the UE reads
the MICH within a given modification period is left to the UE implementation, with the proviso that the UE needs to be
able to detect notifications reliably for its activated MBMS service(s).
The TMGI is structured as follows [16]:
8
7
6
5
4
3
2
1
Temporary Mobile Group Identity IEI
Length of Temporary Mobile Group Identity contents
MBMS Service ID
MCC digit 2
MNC digit 3
MNC digit 2
NOTE:
MCC digit 1
MCC digit 3
MNC digit 1
Octet 1
Octet 2
Octet 3
Octet 4
Octet 5
Octet 6
Octet 7
Octet 8
The MBMS Service identity, which is signalled in [4] (see subclause 10.3.9a.8), concerns a signalling
optimisation of the TMGI.
For the calculation of the NI, the TMGI shall be interpreted as a binary representation of an integer number, represented
by the bitstring formed by the exclusive OR operation of the MBMS Service ID (octets 3 to 5 of the TMGI) and the
PLMN identity (octets 6 to 8 of the TMGI) with the first/ leftmost/ most significant bit corresponding with b8 of the
first octet.
8.4.1.2
Discontinuous Reception via MODIFIED SERVICES INFORMATION
If the UE receives the MODIFIED SERVICES INFORMATION message on the MCCH and determines from its
contents that no service whose information the UE needs to acquire has been modified, the UE may refrain from
receiving the MCCH for the remainder of the modification period.
3GPP
Release 6
37
8.4.2
3GPP TS 25.304 V6.10.0 (2008-03)
Discontinuous Reception for MTCH
If the UE operates DRX on the MTCH, the UE shall receive the MSCH as described in [4] to obtain scheduling
information for the MTCH.
The reception intervals for MBMS services are given by the IE “Service transmissions list” in the MBMS
SCHEDULING INFORMATION message on the MSCH.
8a
MBMS Notification
The structure of the MICH is described in [7] and [14].
The RRC-layer behaviour of a UE receiving an MBMS notification indicator is specified in [4].
9
Void
10
Void
Annex A (informative):
Change history
Change history
Date
10/1999
12/1999
03/2000
06/2000
09/2000
12/2000
TSG #
RP-05
RP-06
RP-06
RP-06
RP-06
RP-06
RP-06
RP-06
RP-06
RP-07
RP-07
RP-07
RP-07
RP-07
RP-08
TSG Doc.
RP-99464
RP-99632
RP-99633
RP-99633
RP-99633
RP-99632
RP-99633
RP-99633
RP-99631
RP-000037
RP-000037
RP-000037
RP-000037
RP-000037
RP-000217
CR
001
002
003
004
006
008
009
011
007
014
018
019
021
025
Rev
2
3
2
2
RP-08
RP-08
RP-08
RP-08
RP-08
RP-08
RP-09
RP-09
RP-09
RP-09
RP-09
RP-10
RP-10
RP-10
RP-10
RP-10
RP-10
RP-10
RP-000217
RP-000217
RP-000217
RP-000217
RP-000217
RP-000217
RP-000355
RP-000355
RP-000355
RP-000355
RP-000355
RP-000565
RP-000565
RP-000565
RP-000565
RP-000565
RP-000565
RP-000565
026
027
028
029
030
031
035
037
039
042
044
046
049
050
051
052
053
054
5
4
3
2
1
1
1
2
1
2
1
1
2
1
Subject/Comment
Approved at TSG-RAN #5 and placed under Change Control
Modification and editorial changes
Specification of Cell reselection procedures in
Integration of Cell Broadcast Service (CBS)
Measurement used as a quality estimate for cell
Discontinuous reception
Barred Cells and Access Control
Introduction of network control of UE measurement
Editorial issues
Cell Selection for DS-41 mode
Modified description of cell search procedure
UE individual DRX cycles in CELL_PCH and URA_PCH states
Cell re-selection criteria including HCS
Modified description of DRX
Triggering of inter-system measurements for cell re-selection when
HCS is used
Cell re-selection
Access Control
Downlink signalling failure
Cell-reselection parameter signalling
Cell Selection and Reselection
CN DRX cycle coefficient
Paging channel selection
Editorial corrections
HCS measurement rules
Usage of Ec/N0 measurement quantity for cell ranking
Correction and restructuring
Support for PLMN selection
Correction of algorithm for paging channel selection
Alignment of use of TEMP_OFFSET parameters with TS 25.331
Clarifications and Editorial Corrections
Clarifications to cell selection and reselection procedures
Removal of immediate cell evaluation
One step cell selection
3GPP
Old
3.0.0
3.0.0
3.0.0
3.0.0
3.0.0
3.0.0
3.0.0
3.0.0
3.1.0
3.1.0
3.1.0
3.1.0
3.1.0
3.2.0
New
3.0.0
3.1.0
3.1.0
3.1.0
3.1.0
3.1.0
3.1.0
3.1.0
3.1.0
3.2.0
3.2.0
3.2.0
3.2.0
3.2.0
3.3.0
3.2.0
3.2.0
3.2.0
3.2.0
3.2.0
3.2.0
3.3.0
3.3.0
3.3.0
3.3.0
3.3.0
3.4.0
3.4.0
3.4.0
3.4.0
3.4.0
3.4.0
3.4.0
3.3.0
3.3.0
3.3.0
3.3.0
3.3.0
3.3.0
3.4.0
3.4.0
3.4.0
3.4.0
3.4.0
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
Release 6
03/2001
38
RP-11
RP-11
RP-11
RP-11
RP-11
RP-11
RP-11
RP-11
RP-11
RP-11
RP-11
RP-12
RP-12
RP-12
RP-13
RP-13
RP-13
RP-13
RP-13
RP-13
RP-14
RP-14
RP-15
RP-15
RP-010022
RP-010022
RP-010022
RP-010022
RP-010022
RP-010022
RP-010022
RP-010200
RP-010022
RP-010022
RP-010037
RP-010305
RP-010435
RP-010305
RP-010539
RP-010539
RP-010539
RP-010539
RP-010539
RP-010539
RP-010756
RP-010756
RP-020063
RP-020063
055
056
058
059
061
062
063
064
065
066
057
072
074
078
080
082
084
086
088
090
092
094
096
098
RP-15
RP-16
RP-18
RP-20
RP-020324
RP-020716
RP-030289
101
104
107
RP-22
RP-23
RP-24
RP-24
RP-24
RP-25
RP-26
RP-26
RP-26
RP-26
RP-26
RP-27
RP-27
RP-27
RP-27
RP-27
RP-27
RP-27
RP-040094
RP-040208
RP-040208
RP-040208
RP-040332
RP-040526
RP-040506
RP-040494
RP-040488
RP-040488
RP-050081
RP-050073
RP-050073
RP-050073
RP-050112
RP-050077
RP-050128
111
113
116
114
119
121
123
124
126
127
125
129
131
132
133
134
137
RP-27
RP-28
RP-28
RP-28
RP-29
RP-29
RP-29
RP-29
RP-050073
RP-050314
RP-050314
RP-050314
RP-050460
RP-050479
RP-050479
RP-050468
139
0140
0141
0142
0145
0146
0147
0148
12/2005
03/2006
RP-29
RP-31
RP-050788 0150
RP-060188 0151
03/2008
RP-31
RP-31
RP-39
RP-060090 0152
RP-060090 0153
RP-080177 0162
06/2001
09/2001
12/2001
03/2002
06/2002
12/2002
06/2003
12/2003
03/2004
06/2004
09/2004
12/2004
03/2005
06/2005
09/2005
1
1
1
3
1
1
1
1
1
1
3
2
1
1
1
2
1
1
2
1
1
3GPP TS 25.304 V6.10.0 (2008-03)
Usage of HCS Parameters in Cell Reselection
Clarification of usage of "Initial UE-Id" for SCCPCH selection
Clarification of paging occasion
Correction in Any Cell Selection State
Correction to the definition of a suitable cell
Correction to discontinuous reception in TDD
Correction of PI calculation for Paging DRX
Equivalent PLMN codes
High quality cell in PLMN selection
Clean-up
Support of 1.28Mcps TDD
Corrections to 25.304
Emergency calls in barred cells
Clarification to usage of measurement thresholds
Clarification to usage of measurement thresholds for HCS
Definition of strongest cell in cell search procedures
Miscellaneous corrections
Correction to cells reserved for operator use
Service type also valid in connected mode
Cell Access Restrictions for emergency calls
Clarification on DRX cycle length in connected mode
Correction to search for available PLMNs
Correction to TDD paging message receiving occasion
Clarification of IMSI at Paging channel selection and DRX
calculation
Upgrade to Release 5 - no technical change
Limitations of CBS reception
Highest HCS priority
Correction to cell selection process to include RRC connected
mode
Upgrade to Release 6 - no technical changes
H criteria & High mobility reselection
Correction to UE selection of reserved cells
Modification of the Sintersearch and SsearchRAT,m behaviour
Selection of suitable cell
HCS measurement rules & high-mobility
Cell selection and reselection parameters
Use of access class restrictions at Inter-RAT cell change
Network Sharing and multiple PLMN identities
TS 25.304 Introduction of MBMS
Addition of MBMS Frequency Layer Convergence to 25.304
Correction to "selected PLMN" in access stratum
Reselection procedure (1235)
RSCP Thresholds
HCS High-mobility measurement rules
H criterion in HCS high-mobility
MBMS Scope
Correction to cell selection and reselection parameters to enable
enhanced cell reselection
Intra frequency measurement rules for HCS
Addition of idle mode cell selection due to FLD
MBMS Frequency Layer Convergence
Removal of sentences in brackets in 25.304
Correction to condition for starting penalty timer in HCS reselection
Selecting the correct priority layer in HCS high mobility
Correction to inter-frequency cell reselection when HCS is not used
Correction to cell reselection when HCS is not used and MBMS PL
is indicated
Structure and use of TMGI for MBMS notification
Effect of partial roaming restrictions on cell reselection and
proposed performance enhancement
Corrected UE behaviour at LR reject
Clarification regarding Access Class and Initial Direct Transfer
Clarification on Treselection for MBMS
3GPP
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
3.5.0
3.6.0
4.0.0
4.0.0
4.0.0
4.1.0
4.1.0
4.1.0
4.1.0
4.1.0
4.1.0
4.2.0
4.2.0
4.3.0
4.3.0
3.6.0
3.6.0
3.6.0
3.6.0
3.6.0
3.6.0
3.6.0
3.6.0
3.6.0
3.6.0
4.0.0
4.1.0
4.1.0
4.1.0
4.2.0
4.2.0
4.2.0
4.2.0
4.2.0
4.2.0
4.3.0
4.3.0
4.4.0
4.4.0
4.4.0
5.0.0
5.1.0
5.2.0
5.0.0
5.1.0
5.2.0
5.3.0
5.3.0
6.0.0
6.1.0
6.1.0
6.1.0
6.2.0
6.3.0
6.3.0
6.3.0
6.3.0
6.3.0
6.4.0
6.4.0
6.4.0
6.4.0
6.4.0
6.4.0
6.4.0
6.0.0
6.1.0
6.2.0
6.2.0
6.2.0
6.3.0
6.4.0
6.4.0
6.4.0
6.4.0
6.4.0
6.5.0
6.5.0
6.5.0
6.5.0
6.5.0
6.5.0
6.5.0
6.4.0
6.5.0
6.5.0
6.5.0
6.6.0
6.6.0
6.6.0
6.6.0
6.5.0
6.6.0
6.6.0
6.6.0
6.7.0
6.7.0
6.7.0
6.7.0
6.7.0
6.8.0
6.8.0
6.9.0
6.8.0
6.8.0
6.9.0
6.9.0
6.9.0
6.10.0
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