ETSI TS 101 376-3-10 V3.2.1 (2011-02)

GEO-Mobile Radio Interface Specifications (Release 3); Third Generation Satellite Packet Radio Service; Part 3: Network specifications; Sub-part 10: Functions related to Mobile Earth Station (MES) in idle mode; GMR-1 3G 43.022

RTS/SES-00315-3-10

General Information

• Status: Published
• Publication Date: 21-Feb-2011
• Technical Committee: SES MSS - SES WG on Mobile Satellite Systems
• Current Stage: 12 - Completion
• Due Date: 26-Jan-2011
• Completion Date: 22-Feb-2011

Standards Content (Sample)

Technical Specification
GEO-Mobile Radio Interface Specifications (Release 3);
Third Generation Satellite Packet Radio Service;
Part 3: Network specifications;
Sub-part 10: Functions related to
Mobile Earth Station (MES) in idle mode;
GMR-1 3G 43.022
GMR-1 3G 43.022 2 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

Reference
RTS/SES-00315-3-10
Keywords
3G, GMPRS, GMR, GPRS, GSM, GSO,
interface, MES, mobile, MSS, radio, satellite,
S-PCN
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ETSI
GMR-1 3G 43.022 3 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

Contents
Intellectual Property Rights . 5
Foreword . 5
Introduction . 6
1 Scope . 8
2 References . 8
2.1 Normative references . 8
2.2 Informative references . 9
3 Definitions and abbreviations . 9
3.1 Definitions . 9
3.2 Abbreviations . 11
4 General description. 11
4.1 Comparison of GMR-1 and GMR-1 3G satellite systems with terrestrial cellular systems . 11
4.2 Idle mode . 12
5 Requirements and technical solutions . 12
5.1 Service capabilities . 12
5.1.1 Normal Service . 13
5.1.2 Limited Service . 13
5.1.3 Position-restricted service (A/Gb mode only) . 14
5.1.4 Alerting Service . 14
5.1.5 No Service . 15
5.2 Spot beam selection . 15
5.2.1 Spot beams . 15
5.2.1.1 Normal spot beams . 15
5.2.1.2 Dark spot beams (A/Gb mode only) . 15
5.2.2 Multiple satellites . 15
5.2.3 Initial spot beam selection . 16
5.2.3.1 Spot beam selection with a co-operating gateway (A/Gb mode only) . 16
5.2.4 Spot beam restriction by system response . 16
5.2.5 System Information (SI) . 17
5.2.6 Transition between normal spot beam and dark spot beam (A/Gb mode only) . 19
5.2.7 Anchor BCCH (A-BCCH) and Temporary BCCH (T-BCCH) (A/Gb mode only) . 19
5.3 PLMN selection and roaming . 19
5.3.1 Selection of PLMN (A/Gb mode only) . 19
5.3.1.1 PLMN selection in GMR-1 3G . 20
5.3.1a Selection of PLMN and roaming (Iu-mode) . 20
5.3.2 Geographic restrictions on service delivery (A/Gb mode only). 20
5.3.2a Geographic restrictions on service delivery (Iu-mode) . 21
5.3.2b Regional provision of service (Iu mode) . 21
5.3.3 Multiple GMR-1/GMR-1 3G systems . 21
5.4 Position determination (A/Gb mode) . 21
5.4.1 Position reporting . 21
5.4.2 GPS receiver system support . 21
5.4.3 Position verification system access . 22
5.5 Dedicated mode to idle mode transition (A/Gb mode only) . 22
5.6 Barred LAs and access control . 22
5.7 Radio constraints . 23
5.8 Transition in/out GMR-1 idle mode (A/Gb mode only) . 23
5.8.1 Modes of operation . 23
5.8.2 Dual Mode Hold Timer . 24
6 Overall process structure . 24
6.1 Process goal . 24
6.2 Spot beam selection process . 26
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GMR-1 3G 43.022 4 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

6.2.1 List of states for the spot beam selection process . 26
6.2.2 Initial spot beam selection . 28
6.2.3 Spot beam reselection . 29
6.2.4 Gateway response to channel requests . 29
6.2.5 BCCH selection . 30
6.2.5.1 Primary BCCH list . 30
6.2.5.2 Selection procedure for BCCHs . 30
6.2.5.3 Spot beam verification . 31
6.2.5.4 Availability expansion and restriction by system responses . 32
6.2.6 Dedicated mode to idle mode transition (A/Gb mode only) . 32
6.2.7 Limited service . 33
6.3 PLMN selection process (A/Gb mode only) . 33
6.3.1 List of states for the PLMN selection process . 33
6.3.1.1 List of states for automatic mode (figure 6.3) . 34
6.3.1.2 List of states for manual mode (figure 6.4) . 35
6.3.2 Registration on a PLMN . 35
6.3.3 PLMN selection . 36
6.3.3.1 MES switch-on or recovery from lack of coverage . 36
6.3.3.1.1 Automatic network selection mode procedure . 36
6.3.3.1.2 Manual network selection mode procedure . 37
6.3.3.2 User reselection . 37
6.3.3.2.1 Automatic network selection mode . 37
6.3.3.2.2 Manual network selection mode . 37
6.3.4 Abnormal cases . 37
6.3.5 Roaming not allowed in this LA . 38
6.3.6 PLMN selection process (Iu-mode) . 38
6.4 Position determination process . 38
6.4.1 Idle mode parameters . 38
6.4.2 Receiver operation . 38
6.4.3 Configuration of position determination . 38
6.4.4 "Current" position storage. 39
6.4.5 "Reported" position storage . 39
6.4.6 Distance check . 39
6.5 Location registration process (A/Gb mode only) . 39
6.5.1 List of states for location registration (figure 6.5) . 40
6.5.2 General . 41
6.5.3 Initiation of location registration . 42
6.5.4 Periodic location registration . 43
6.5.5 lMSl attach/detach operation . 44
6.5.6 Location registration process (Iu-mode only) . 44
6.6 User indications . 44
6.6.1 Service indication . 44
6.6.2 GMR-1 or GMR-1 3G service indication . 44
6.6.3 GPS indication . 45
6.7 Non-volatile storage requirements. 45
6.8 BCCH broadcasting and storage . 45
6.9 Pageability of the mobile subscriber . 46
6.10 MM/GMM restart procedure . 46
6.11 Gateway (GW) selection (Iu mode only) . 46
6.11.1 Gateway Selection Frequency. 46
6.11.2 Load Factor Assessment . 46
Annex A (informative): Bibliography . 48
History . 50

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GMR-1 3G 43.022 5 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Satellite Earth Stations and
Systems (SES).
The contents of the present document are subject to continuing work within TC-SES and may change following formal
TC-SES approval. Should TC-SES modify the contents of the present document it will then be republished by ETSI
with an identifying change of release date and an increase in version number as follows:
Version 3.m.n
where:
• the third digit (n) is incremented when editorial only changes have been incorporated in the specification;
• the second digit (m) is incremented for all other types of changes, i.e. technical enhancements, corrections,
updates, etc.
The present document is part 3, sub-part 10 of a multi-part deliverable covering the GEO-Mobile Radio Interface
Specifications (Release 3); Third Generation Satellite Packet Radio Service, as identified below:
Part 1: "General specifications";
Part 2: "Service specifications";
Part 3: "Network specifications":
Sub-part 1: "Network Functions";
Sub-part 2: "Network Architecture";
Sub-part 3: "Numbering, addressing and identification";
Sub-part 4: "Organization of Subscriber Data";
Sub-part 5: "Technical realization of Supplementary Services";
Sub-part 6: "Location Registration and Position Identification Procedures";
Sub-part 7: "Discontinuous Reception (DRX)";
Sub-part 8: "Support of Dual-Tone Multifrequency Signalling (DTMF)";
Sub-part 9: "Security related Network Functions";
Sub-part 10: "Functions related to Mobile Earth Station (MES) in idle mode";
Sub-part 11: "Technical realization of the Short Message Service (SMS) Point-to-Point (PP)";
Sub-part 12: "Technical realization of the Short Message Service Cell Broadcast (SMSCB)";
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GMR-1 3G 43.022 6 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

Sub-part 13: "Technical realization of group 3 facsimile using transparent mode of transmission";
Sub-part 14: "Transmission Planning Aspects of the Speech Service in the GMR-1 system";
Sub-part 15: "Line Identification supplementary service - Stage 2";
Sub-part 16: "Call Barring (CB) supplementary services - Stage 2";
Sub-part 17: "Unstructured Supplementary Service Data (USSD) - Stage 2";
Sub-part 18: "Terminal-to-Terminal Call (TtT)";
Sub-part 19: "Optimal Routing technical realization";
Sub-part 20: "Technical realization of High-Penetration Alerting";
Sub-part 21: "Position Reporting services; Stage 2 Service description";
Sub-part 22: "Overall description of the GMPRS radio interface; Stage 2";
Sub-part 23: "Radio Access Network; Overall description - Stage 2";
Part 4: "Radio interface protocol specifications";
Part 5: "Radio interface physical layer specifications";
Part 6: "Speech coding specifications";
Part 7: "Terminal adaptor specifications".
Introduction
GMR stands for GEO (Geostationary Earth Orbit) Mobile Radio interface, which is used for Mobile Satellite Services
(MSS) utilizing geostationary satellite(s). GMR is derived from the terrestrial digital cellular standard GSM and
supports access to GSM core networks.
The present document is part of the GMR Release 3 specifications. Release 3 specifications are identified in the title
and can also be identified by the version number:
• Release 1 specifications have a GMR 1 prefix in the title and a version number starting with "1" (V1.x.x).
• Release 2 specifications have a GMPRS 1 prefix in the title and a version number starting with "2" (V2.x.x).
• Release 3 specifications have a GMR-1 3G prefix in the title and a version number starting with "3" (V3.x.x).
The GMR release 1 specifications introduce the GEO Mobile Radio interface specifications for circuit mode Mobile
Satellite Services (MSS) utilizing geostationary satellite(s). GMR release 1 is derived from the terrestrial digital cellular
standard GSM (phase 2) and it supports access to GSM core networks.
The GMR release 2 specifications add packet mode services to GMR release 1. The GMR release 2 specifications
introduce the GEO Mobile Packet Radio Service (GMPRS). GMPRS is derived from the terrestrial digital cellular
standard GPRS (included in GSM Phase 2+) and it supports access to GSM/GPRS core networks.
The GMR release 3 specifications evolve packet mode services of GMR release 2 to 3rd generation UMTS compatible
services. The GMR release 3 specifications introduce the GEO-Mobile Radio Third Generation (GMR-1 3G) service.
Where applicable, GMR-1 3G is derived from the terrestrial digital cellular standard 3GPP and it supports access to
3GPP core networks.
Due to the differences between terrestrial and satellite channels, some modifications to the GSM or 3GPP standard are
necessary. Some GSM and 3GPP specifications are directly applicable, whereas others are applicable with
modifications. Similarly, some GSM and 3GPP specifications do not apply, while some GMR specifications have no
corresponding GSM or 3GPP specification.
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GMR-1 3G 43.022 7 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

Since GMR is derived from GSM and 3GPP, the organization of the GMR specifications closely follows that of GSM
or 3GPP as appropriate. The GMR numbers have been designed to correspond to the GSM and 3GPP numbering
system. All GMR specifications are allocated a unique GMR number. This GMR number has a different prefix for
Release 2 and Release 3 specifications as follows:
• Release 1: GMR n xx.zyy
• Release 2: GMPRS n xx.zyy
• Release 3: GMR-1 3G xx.zyy
where:
- xx.0yy (z = 0) is used for GMR specifications that have a corresponding GSM or 3GPP specification. In
this case, the numbers xx and yy correspond to the GSM or 3GPP numbering scheme.
- xx.2yy (z = 2) is used for GMR specifications that do not correspond to a GSM or 3GPP specification. In
this case, only the number xx corresponds to the GSM or 3GPP numbering scheme and the number yy is
allocated by GMR.
- n denotes the first (n = 1) or second (n = 2) family of GMR specifications.
A GMR system is defined by the combination of a family of GMR specifications and GSM and 3GPP specifications as
follows:
• If a GMR specification exists it takes precedence over the corresponding GSM or 3GPP specification (if any).
This precedence rule applies to any references in the corresponding GSM or 3GPP specifications.
NOTE: Any references to GSM or 3GPP specifications within the GMR specifications are not subject to this
precedence rule. For example, a GMR specification may contain specific references to the corresponding
GSM or 3GPP specification.
• If a GMR specification does not exist, the corresponding GSM or 3GPP specification may or may not apply.
The applicability of the GSM and 3GPP specifications is defined in GMR-1 3G 41.201 [2].
The clause numbering and the table numbering and figure numbering in the present document are aligned to the
corresponding numbering of GMPRS-1 03.022 [15] as far as possible.
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GMR-1 3G 43.022 8 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

1 Scope
The present document gives an overview of the tasks undertaken by a GMR-1 Mobile Earth Station (MES) when in idle
mode, that is, switched on but not having a dedicated channel allocated, e.g. not making or receiving a call. It also
describes relevant network functions. The idle mode functions are also performed by a MES as long as no dedicated
channel is allocated to the MES.
The present document outlines how the idle mode operation shall be implemented. Further details are given in
GMR-1 3G 44.008 [4] and GMR-1 3G 45.008 [7].
Clause 4 of the present document gives a general description of the idle mode process. Clause 5 outlines the main
requirements and technical solutions of those requirements. Clause 6 describes the processes used in idle mode.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
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] GMPRS-1 01.004 (ETSI TS 101 376-1-1): "GEO-Mobile Radio Interface Specifications
(Release 2) General Packet Radio Service; Part 1: General specifications;
Sub-part 1: Abbreviations and acronyms".
NOTE: This is a reference to a GMR-1 Release 2 specification. See the introduction for more details.
[2] GMR-1 3G 41.201 (ETSI TS 101 376-1-2): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 1: General specifications;
Sub-part 2: Introduction to the GMR-1 family".
[3] GMR-1 03.299 (ETSI TS 101 376-3-21): "GEO-Mobile Radio Interface Specifications;
Part 3: Network specifications; Sub-part 21: Position Reporting services; Stage 2 Service
description".
NOTE: This is a reference to a GMR-1 Release 1 specification. See the introduction for more details.
[4] GMR-1 3G 44.008 (ETSI TS 101 376-4-8): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 4: Radio interface protocol
specifications; Sub-part 8: Mobile Radio Interface Layer 3 Specifications".
[5] GMR-1 3G 45.002 (ETSI TS 101 376-5-2): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 5: Radio interface physical layer
specifications; Sub-part 2: Multiplexing and Multiple Access; Stage 2 Service Description".
[6] GMR-1 3G 45.005 (ETSI TS 101 376-5-5): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 5: Radio interface physical layer
specifications; Sub-part 5: Radio Transmission and Reception".
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GMR-1 3G 43.022 9 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

[7] GMR-1 3G 45.008 (ETSI TS 101 376-5-6): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 5: Radio interface physical layer
specifications; Sub-part 6: Radio Subsystem Link Control".
[8] GMR-1 3G 45.010 (ETSI TS 101 376-5-7): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 5: Radio interface physical layer
specifications; Sub-part 7: Radio Subsystem Synchronization".
[9] 3GPP TS 43.022 (ETSI TS 143 022): "3rd Generation Partnership Project; Technical Specification
Group GSM/EDGE Radio Access Network; Functions related to Mobile Station (MS) in idle
mode and group receive mode".
[10] Void.
[11] 3GPP TS 23.122 (ETSI TS 123 122): "3rd Generation Partnership Project; Technical Specification
Group Core Network and Terminals; Non-Access-Stratum (NAS) functions related to Mobile
Station (MS) in idle mode".
[12] 3GPP TS 23.060 (ETSI TS 123 060): "3rd Generation Partnership Project; Technical Specification
Group Services and System Aspects; General Packet Radio Service (GPRS); Service description;
Stage 2".
[13] 3GPP TS 24.008 (ETSI TS 124 008): "3rd Generation Partnership Project; Technical Specification
Group Core Network and Terminals; Mobile radio interface Layer 3 specification; Core network
protocols; Stage 3".
[14] GMR-1 3G 44.118 (ETSI TS 101 376-4-13): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 4: Radio interface protocol
specifications; Sub-part 13: Radio Resource Control (RRC) protocol; Iu Mode".
[15] GMPRS-1 03.022 (ETSI TS 101 376-3-10): "GEO-Mobile Radio Interface Specifications
(Release 2) General Packet Radio Service; Part 3: Network specifications; Sub-part 10: Functions
related to Mobile Earth Station (MES) in idle mode".
NOTE: This is a reference to a GMR-1 Release 2 specification. See the introduction for more details.
[16] GMR-1 3G 44.160 (ETSI TS 101 376-4-14): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 4: Radio interface protocol
specifications; Sub-part 14: Mobile Earth Station (MES) - Base Station System (BSS) interface;
Radio Link Control/Medium Access Control (RLC/MAC) protocol; Iu Mode".
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] 3GPP TS 25.413 (ETSI TS 125 413): "3rd Generation Partnership Project; Technical Specification
Group Radio Access Network; UTRAN Iu interface Radio Access Network Application Part
(RANAP) signalling".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in GMR-1 3G 41.201 [2] and the following
apply:
A-BCCH (A/Gb mode only): broadcast channel which:
1) uses an ARFCN on the BCCH_FULL_LIST for the serving satellite;
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GMR-1 3G 43.022 10 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

2) is illuminated permanently in a satellite system;
3) is always be transmitted with full BCCH power;
4) can be listed on a neighbour BCCH list; and
5) can be used for RSSI-based spot beam selection.
A/Gb mode: MES operating mode that applies with a Release 1 (GMR-1) or Release 2 (GMPRS-1) radio access
network
NOTE: For the multi system case the mode is determined by the current serving radio access network.
BCCH carrier: frequency carrier which is used by either an FCCH or an FCCH3 multiplexed with a BCCH/CCCH
Dark Beam (A/Gb mode only): spot beam that is not activated and has no satellite resource allocated, or a spot beam
that is activated but not illuminated
NOTE: To activate a beam is to allocate Subband and Frequency Slot resource, and perform routing over the
satellite payload. To illuminate a beam is to start BCCH signal transmission using already activated
satellite resource.
Iu mode: MES operating mode that applies with a Release 3 (GMR-1 3G) radio access network
NOTE: For the multi system case the mode is determined by the current serving radio access network.
Location Registration (LR): may be either the Location Updating procedure or the Routing Area Update procedure
NOTE 1: A MES that is IMSI attached to non-GMPRS services only performs location registration by the Location
Updating procedure. A MES that is IMSI attached to GMPRS services or to GMPRS and non-GMPRS
services performs location registration by the Routing Area Update procedure only when in a network of
network operation mode I. A MES performs location registration by the Routing Area Update procedure
(Iu mode) when in a network of network operation mode I or II.
NOTE 2: Both procedures are performed independently by the MES when it is IMSI attached to GMPRS and
non-GMPRS services in a network of network operation mode II or III (see 3GPP TS 23.060 [12]).
NOTE 3: Network operation modes I and II for GMR-1 3G Iu mode correspond to modes I and II for A/Gb mode,
respectively. Mode III applies to A/Gb mode only, but not to Iu mode (see 3GPP TS 23.060 [12]).
Registration Area (RA): area in which mobile stations may roam without a need to perform location registration
NOTE: The registration area corresponds to the Location Area (LA) for performing location updating procedure,
and it corresponds to the routing area for performing the routing area update procedure.
Routing Area Indicator (RAI): Routing Area Indicator has a similar format as the LAI and is similar in function to the
LAI, except that the RAI is used for provision of data services
T-BCCH (A/Gb mode only): broadcast channel which:
1) can use any frequency, i.e. it may be assigned to an ARFCN not given in the BCCH_FULL_LIST for the
serving satellite;
2) might not be illuminated or activated all the time;
3) might not be transmitted with full BCCH power;
4) is not listed in the neighbour BCCH list; and
5) is not used for RSSI-based spot beam selection.
spot beam: defined by its spot beam ID
NOTE: Several BCCH carriers may share the same spot beam ID. This indicates that the geographic coverage
area of the BCCH carriers is coincident.
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GMR-1 3G 43.022 11 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

3.2 Abbreviations
For the purposes of the present document, the abbreviations given in GMPRS-1 01.004 [1] apply.
4 General description
4.1 Comparison of GMR-1 and GMR-1 3G satellite systems
with terrestrial cellular systems
A GMR-1 or GMR-1 3G satellite system differs from a terrestrial cellular system in several important respects but also
incorporates a number of the same radio and network architecture features.
In terrestrial cellular system, a cell is always wholly contained within a single LA. In a GMR-1 or GMR-1 3G satellite
system, each BCCH carrier shall be associated with a single LAI. Multiple BCCH channels may be provided in the
same spot beam with identical coincident geographic coverage or with overlapping geographic coverage where the
individual BCCH carrier LAIs may be associated with the same or different PLMNs.
In a cellular system, a cell always provides access to only one base station and only one MSC or SGSN Core Network
(CN) elements. In GMR-1 or GMR-1 3G, a BCCH carrier within a spot beam shall provide access to one GS and to one
CN element. Multiple BCCH carriers within coincident or overlapping spot beams may provide access to different GS
and different CN elements. The gateways may have the same or different PLMN.
In a terrestrial cellular system, PLMN selection has priority over cell selection, and any suitable cell of a selected
PLMN can be selected even if there are other stronger cells belonging to other PLMNs. In GMR-1 or GMR-1 3G, only
the strongest or next to the strongest spot beam from a particular satellite should be camped on, and the PLMN should
be selected from the BCCHs of these spot beams.
Having coverage from more than one satellite of a single system operator is also a distinct attribute of a GMR-1 or
GMR-1 3G system, with no comparable situation in a terrestrial cellular system.
In a terrestrial cellular system, the position of the MS is indicated by cell selection and, optionally, by additional
functionality provided by GPS or some other technique. In a GMR-1 or GMR-1 3G system, if the MES supports GPS
capability the MES is required to perform GPS position determination, use that position as part of spot beam selection,
and report its position to the network during the system access. If the MES does not support GPS capability, spot beam
selection is based on power measurements. In a GMR-1 or GMR-1 3G system, spot beam selection may include
Gateway selection where suitable or equivalent coverage is provided by spot beams associated with different Gateways.
In a terrestrial cellular system, any detectable signal can be a potential candidate for camp-on. However, due to link
margins for the satellite frequency correction and broadcast channels (FCCH and BCCH) and the beamforming
properties of the satellite antenna, it is possible to receive a signal that is not from the spot beam associated with the
MES's location. The MES scan procedure shall avoid camping on these spurious signals.
In a terrestrial cellular system, registration is permitted on any network for which a minimally acceptable signal can be
detected. In a GMR-1 or GMR-1 3G system, and assuming that the spurious signals described above have been rejected,
registration is not always allowed on detectable networks. Registration may be position based, as will be described later.
In this regard, the GS may participate in the PLMN and RA selection process, which is never the case in a cellular
system. However, a GMR-1 or GMR-1 3G system may or may not require MES position reporting.
The GMR-1 or GMR-1 3G system has different service levels: Normal Service, Alerting Service, Limited Service, and
No Service. Alerting service is optional for both the network and the MES.
The GMR-1 or GMR-1 3G system in A/Gb mode may use Dark Beams to manage the assignment of resources to spot
beams or to minimize unnecessary power consumption on the satellite. A spot beam may not have satellite frequency or
timeslot resources allocated, or may have resources allocated but may not be transmitting a BCCH signal. In either case
the spot beam is called a Dark Beam.
ETSI
GMR-1 3G 43.022 12 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

4.2 Idle mode
The GMR-1 idle mode can be subdivided into four processes:
• Spot beam selection and reselection.
• PLMN selection.
• GPS position determination (for suitably equipped MESs).
• Location registration.
The GMR-1 3G idle mode includes all of these GMR-1 idle mode processes plus one additional process:
• Gateway selection.
Clause 5 introduces the issues to be accommodated by idle mode, and describes at a general level how the idle mode
processes shall specifically solve them.
The functional aspects of the idle mode process are described in clause 5. The relationship between these processes is
illustrated in figures 6.1 and 6.1a (for GMR-1 3G). The internal states and state transitions within each process are
shown in figures 6.2 to 6.5.
5 Requirements and technical solutions
The following clauses list the main requirements of idle mode operation and give an outline of the technical solution.
5.1 Service capabilities
The MES shall provide three levels of service: Normal Service, Limited Service, and No Service. The MES may
provide two additional levels of service: Position-Restricted Service (A/Gb mode only) and Alerting Service. The
service levels are shown schematically in figure 5.1.
ETSI
GMR-1 3G 43.022 13 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

Normal Service
Limited Service
or
Position-restricted Service
(A/Gb mode)
Signal
Strength
Alerting Service
No   Service
No   Service
Not Registered Registered
BACH are in reorganization, or
reregistration was required after
dedicated mode but was not
completed
Figure 5.1: Service states
5.1.1 Normal Service
Normal Service is the capability wherein the MES has full service access to the GMR-1 or GMR-1 3G system and
sufficient signal quality for two-way communication. In order to be in Normal Service, the MES shall be registered. For
Normal Service, the MES shall select a suitable spot beam, tune to that spot beam's BCCH + CCCH associated with the
selected PLMN, and register within the PLMN. If it registers successfully, it has Normal Service.
5.1.2 Limited Service
There are a number of situations in which the MES is not allowed to register with any PLMN or the PLMN denies
registration, but the signal strength is acceptable for Normal Service. The inability to obtain Normal Service is due to
one or more of the following factors:
• No SIM in the MES.
• A "PLMN not allowed" or "LA not allowed" response to an LR.
• An "illegal MES" "illegal MES-ME" response to an LR. Any SIM in the MES-ME is then considered
"invalid".
• "IMSI unknown in HLR". This only impacts the non-GMPRS update state. The service state for MESs capable
of GMPRS and non-GMPRS services is dependent upon the outcome of the routing area update.
ETSI
GMR-1 3G 43.022 14 ETSI TS 101 376-3-10 V3.2.1 (2011-02)

• A "GMPRS not allowed" response to an LR of a MES attached to GMPRS services only. The service state of
MESs capable of both GMPRS and non-GMPRS services depends on the outcome of the location updating, as
"GMPRS not allowed" only has impact on the GMPRS update state.
• The SIM status is "Updated" but the MES shall reregister before it can obtain Normal Service. It is camped in
a different LAI from the one on which it is registered. See clauses 5.1.3 and 5.5.
For a MES, the inability to obtain Normal Service and entry into the Limited Service states may in addition be due to
one of the following factors related to an attempt to perform a GMPRS
...