ETSI TS 101 376-5-6 V2.3.1 (2008-08)

GEO-Mobile Radio Interface Specifications (Release 2); General Packet Radio Service; Part 5: Radio interface physical layer specifications; Sub-part 6: Radio Subsystem Link Control; GMPRS-1 05.008

RTS/SES-00303-5-6

General Information

• Status: Published
• Publication Date: 07-Aug-2008
• Technical Committee: SES MSS - SES WG on Mobile Satellite Systems
• Current Stage: 12 - Completion
• Due Date: 08-Aug-2008
• Completion Date: 08-Aug-2008

Standards Content (Sample)

ETSI TS 101 376-5-6 V2.3.1 (2008-08)
Technical Specification


GEO-Mobile Radio Interface Specifications (Release 2);
General Packet Radio Service;
Part 5: Radio interface physical layer specifications;
Sub-part 6: Radio Subsystem Link Control;
GMPRS-1 05.008

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GMPRS-1 05.008 2 ETSI TS 101 376-5-6 V2.3.1 (2008-08)




Reference
RTS/SES-00303-5-6
Keywords
control, gateway, GMPRS, GMR, GPRS, GSM,
GSO, interface, MES, mobile, MSC, MSS, radio,
satellite, S-PCN
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GMPRS-1 05.008 3 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

Contents
Intellectual Property Rights.5
Foreword.5
Introduction .6
1 Scope.7
2 References.7
2.1 Normative references.7
2.2 Informative references.8
3 Definitions and abbreviations.8
3.1 Definitions.8
3.2 Abbreviations.10
4 General.10
5 RF power control.10
6 Radio link failure.10
7 Idle mode tasks.11
8 Network prerequisites.11
9 Aspects of Discontinuous Transmission (DTX).11
10 Radio link measurements .11
11 Control parameters .11
12 GMPRS mode tasks .11
12.1 GMPRS spot beam selection and reselection .11
12.1.1 BCCH type identification .11
12.1.2 Spot beam selection .12
12.1.3 Spot beam reselection .12
12.2 Idle mode link loss .12
12.3 Link adaptation.12
12.3.1 Objective and overall procedure .12
12.3.2 Power control parameters .13
12.3.3 PAN transmission.13
12.3.4 PAR transmission.13
12.3.5 MES output power.13
12.3.5.1 Open-loop power control at a terminal type C MES.13
12.3.5.1.1 Signal quality estimation .13
12.3.5.1.2 Open-loop power control procedure.14
12.3.6 GS output power .14
12.3.7 Radio link measurements and accuracy requirements .14
12.3.8 Signal Quality Indicator Report (SQIR) and Signal Quality Standard Deviation (SQISDR)
transmissions.15
12.3.9 Code rate adaptation .17
12.3.9.1 Terminal type A.17
12.3.9.2 Terminal type C .17
12.3.9.3 Terminal type D .18
12.4 UT Link Quality Report (UTLQR) handling.18
12.5 Timing for the power level adjustment.18
Annex A (informative): Pseudocode for power control .19
Annex B (informative): Per-burst SQI estimation .20
Annex C (informative): Position determination at the MES .21
ETSI

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GMPRS-1 05.008 4 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

Annex D (informative): Bibliography.22
History .23

ETSI

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GMPRS-1 05.008 5 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

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 2.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 5, sub-part 6 of a multi-part deliverable covering the GEO-Mobile Radio Interface
Specifications (Release 2); General Packet Radio Service, as identified below:
Part 1: "General specifications";
Part 2: "Service specifications";
Part 3: "Network specifications";
Part 4: "Radio interface protocol specifications";
Part 5: "Radio interface physical layer specifications";
Sub-part 1: "Physical Layer on the Radio Path: General Description";
Sub-part 2: "Multiplexing and Multiple Access; Stage 2 Service Description";
Sub-part 3: "Channel Coding";
Sub-part 4: "Modulation";
Sub-part 5: "Radio Transmission and Reception";
Sub-part 6: "Radio Subsystem Link Control";
Sub-part 7: "Radio Subsystem Synchronization";
Part 6: "Speech coding specifications";
Part 7: "Terminal adaptor specifications".
ETSI

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GMPRS-1 05.008 6 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

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 2 specifications. Release 2 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.).
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.
Due to the differences between terrestrial and satellite channels, some modifications to the GSM standard are necessary.
Some GSM specifications are directly applicable, whereas others are applicable with modifications. Similarly, some
GSM specifications do not apply, while some GMR specifications have no corresponding GSM specification.
Since GMR is derived from GSM, the organization of the GMR specifications closely follows that of GSM. The GMR
numbers have been designed to correspond to the GSM numbering system. All GMR specifications are allocated a
unique GMR number. This GMR number has a different prefix for Release 2 specifications as follows:
• Release 1: GMR-n xx.zyy.
• Release 2: GMPRS-n xx.zyy.
where:
- xx.0yy (z = 0) is used for GMR specifications that have a corresponding GSM specification. In this case,
the numbers xx and yy correspond to the GSM numbering scheme.
- xx.2yy (z = 2) is used for GMR specifications that do not correspond to a GSM specification. In this
case, only the number xx corresponds to the GSM 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 specifications as follows:
• If a GMR specification exists it takes precedence over the corresponding GSM specification (if any). This
precedence rule applies to any references in the corresponding GSM specifications.
NOTE: Any references to GSM 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
specification.
• If a GMR specification does not exist, the corresponding GSM specification may or may not apply. The
applicability of the GSM specifications is defined in GMPRS-1 01.201 [9].
ETSI

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GMPRS-1 05.008 7 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

1 Scope
The present document specifies several control aspects for the radio link between the Mobile Earth Station (MES) and
the Gateway Station (GS) in the GMR-1 Mobile Satellite System. It specifies the operation of power control and defines
dead link detection. It makes requirements for DTX operation.
The present document also defines requirements for the MES for monitoring system information, as prerequisites to
system access, and upon exit from dedicated mode. It makes requirements for spot beam selection and reselection. It
defines the nature of the measurements that the MES uses to implement these processes.
Timing and frequency control aspects of link control are to be found in GMPRS-1 05.010 [6], and messages for timing
and frequency control are defined in GMPRS-1 04.008 [3].
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably,
the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the
reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the
method of access to the referenced document and the full network address, with the same punctuation and use of upper
case and lower case letters.
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 indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
[1] 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;
GMPRS-1 01.004".
[2] 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; GMPRS-1 03.022".
[3] ETSI TS 101 376-4-8: "GEO-Mobile Radio Interface Specifications (Release 2) General Packet
Radio Service; Part 4: Radio interface protocol specifications; Sub-part 8: Mobile Radio Interface
Layer 3 Specifications; GMPRS-1 04.008".
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GMPRS-1 05.008 8 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

[4] ETSI TS 101 376-5-3: "GEO-Mobile Radio Interface Specifications (Release 2) General Packet
Radio Service; Part 5: Radio interface physical layer specifications; Sub-part 3: Channel Coding;
GMPRS-1 05.003".
[5] ETSI TS 101 376-5-5: "GEO-Mobile Radio Interface Specifications (Release 2) General Packet
Radio Service; Part 5: Radio interface physical layer specifications; Sub-part 5: Radio
Transmission and Reception; GMPRS-1 05.005".
[6] ETSI TS 101 376-5-7: "GEO-Mobile Radio Interface Specifications (Release 2) General Packet
Radio Service; Part 5: Radio interface physical layer specifications; Sub-part 7: Radio Subsystem
Synchronization; GMPRS-1 05.010".
[7] ETSI TS 101 376-5-6: "GEO-Mobile Radio Interface Specifications (Release 1); Part 5: Radio
interface physical layer specifications; Sub-part 6: Radio Subsystem Link Control;
GMR-1 05.008".
NOTE: This is a reference to a GMR-1 Release 1 specification. See the introduction for more details.
[8] ETSI TS 101 376-4-12: "GEO-Mobile Radio Interface Specifications (Release 2); General Packet
Radio Service; Part 4: Radio interface protocol specifications; Sub-part 12: Mobile Earth Station
(MES) - Base Station System (BSS) interface; Radio Link Control/Medium Access Control
(RLC/MAC) protocol; GMPRS-1 04.060".
[9] ETSI TS 101 376-1-2: "GEO-Mobile Radio Interface Specifications (Release 2); General Packet
Radio Service; Part 1: General specifications; Sub-part 2: Introduction to the GMR-1 family;
GMPRS-1 01.201".
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
Not applicable.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in GMPRS-1 01.201 [9] and the following
apply:
Average Power Used (APU): at the beginning of each call, the MES will start a running power-averaged PAS setting,
expressed in dB
NOTE: This parameter will be transmitted upon receipt of an INFORMATION REQUEST message from the
network, with a power control request code.
BCCH_FULL_LIST: list of all the broadcast control channel (BCCH) numbers used by the network
BCCH_NEIGHBOR_LIST: list of the neighbouring spot beams' BCCH numbers, starting timeslots, and system
information cycle offsets
Call Quality Metric (CQM): at the beginning of each call, the MES will start a running average of the percentage of
post-FEC burst errors occurring for the call
NOTE: This parameter will be transmitted upon receipt of an INFORMATION REQUEST message from the
network, with a power control request code.
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GMPRS-1 05.008 9 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

criterion C1: used by the MES for detecting the presence of the frequency control channel (FCCH) and switching out
of the frequency search state
NOTE: C1 is the minimum usable threshold on the received LQI at the MES that has to be satisfied before it
camps on the system.
Link Quality Indication (LQI): amount of available link margin with respect to SQT, expressed in dB
NOTE: A positive value indicates the amount of additional link margin in reserve. A negative value indicates that
power control is at saturation and that the SQT is not being met by the indicated value.
link margin: difference (in dB) between the SQI at the receiver corresponding to the maximum transmit power level
and the SQT
Open Loop Threshold (Olthresh): the parameter Olthresh is the threshold on the LQI estimate before activating open
loop power control
Open Loop Gain (Olgain): the parameter Olgain is the loop gain for open loop control
Power Attenuation Notification (PAN): the attenuation, in dB, used by the transmitter in the power control loop,
relative to the maximum transmit power level
Power Attenuation Request (PAR): the attenuation, in dB, requested by the receiver in the power control loop,
relative to the maximum transmit power level
power control loop gain: number by which the difference between SQT and SQI is multiplied to derive the power
correction value.
Two loop gains are defined:
• GainDn: used as the loop gain if the difference between SQT and SQI is negative;
• GainUp: used as the loop gain otherwise (i.e. if the difference between SQT and SQI is not negative).
NOTE: The loop gain is a unitless number with a default value of 1,0.
Power Control Topped-Out (PCTO): at the beginning of each call, the MES will start a running average of the
percentage of messages for which the calculated PAS is less than PASmin
NOTE: This parameter will be transmitted upon receipt of an INFORMATION REQUEST message from the
network, with a power control request code.
radio link failure counter S: counter whose value of zero determines the failure of the radio link
reserve link margin: difference (in dB) between the SQI corresponding to the maximum transmit power level and the
actual SQI at the receiver
RADIO_LINK_TIMEOUT: maximum value of the radio link failure counter S
Received Signal Strength Indication (RSSI): root mean squared (rms) value of the signal received at the receiver
antenna
NOTE: The RSSI estimate is compensated for all the time-varying processes (such as automatic gain control) that
affect the estimation procedure for obtaining a relative measure to use in comparing the strength of
signals received at different times.
SB_RESELECT_HYSTERESIS: value in dB by which a nonserving beam's BCCH power measurement must exceed
the serving beam's BCCH power before the MES switches to the nonserving beam
SB_SELECTION_POWER: during the spot beam selection and reselection, the MES selects only those BCCH
carriers whose receive power is within SB_SELECTION_POWER dB of the strongest BCCH carrier
SB_RESELECTION_TIMER: maximum time interval between consecutive spot beam reselection procedures
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GMPRS-1 05.008 10 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

Signal Quality Indication (SQI) or Signal Quality Measurement (SQM): the estimate of the ratio of signal power to
the noise and the interference power S / (N + I) formed at the receiver in the power control loop
NOTE 1: The terms SQI and SQM are used interchangeably in the present document. The term SQI is used for the
descriptions related to circuit-switched operation, whereas the term SQM is used for the
packet-data-related descriptions in the present document.
NOTE 2: This estimate, averaged over one burst, is denoted here as SQIj or SQM (estimate for jth burst). For the
j
power control algorithm in the circuit-switched operation, MES averages this estimate is averaged over
six frames and the averaged estimate is denoted as .
SQI6
Signal Quality Target (SQT): desired receive signal quality, and it is defined as the targeted value for the ratio of the
signal power to the noise and interference power
NOTE: The SQT is derived from a reference threshold and an allowance for fading and Doppler shift.
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in GMPRS-1 01.004 [1] and the following apply:
APU Average Power Used
CQM Call Quality Metric
Olgain Open Loop Gain
Olthresh Open Loop Threshold
PCTO Power Control Topped Out
SQIR Signal Quality Indicator Report
SQISDR Signal Quality Standard Deviation
UTLQR UT Link Quality Report
4 General
Same as clause 4 in GMR-1 05.008 [7].
5 RF power control
Same as clause 5 in GMR-1 05.008 [7].
6 Radio link failure
Same as clause 6 in GMR-1 05.008 [7] for dedicated mode, with the following modifications for packet service in
packet transfer mode:
• Link failure may occur as result of adverse channel conditions. The MES shall detect link failure by
determining that the received E /N is below 2,5 dB for terminal type A and type D, and below 3,0 dB for
s o
terminal type C. This determination may be based on Bit Error Rate estimation. The Bit Error Rate estimate
may be based on known bits within the packet bursts, or on an examination of the Golay decoder outputs.
• This detection procedure shall be performed for each successive link failure measurement interval.
• The measurement interval is defined as LINK_FAILURE_MEASUREMENT_INTERVAL. The GS shall
broadcast the value of LINK_FAILURE_MEASUREMENT_INTERVAL as part of system information in
BCCH (see GMPRS-1 04.008 [3]), and the default value is 10 seconds.
• In case of the radio link failure detection, the MES shall perform the procedure specified in
GMPRS-1 04.060 [8].
ETSI

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GMPRS-1 05.008 11 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

7 Idle mode tasks
Same as clause 7 in GMR-1 05.008 [7].
8 Network prerequisites
Same as clause 8 in GMR-1 05.008 [7].
9 Aspects of Discontinuous Transmission (DTX)
Same as clause 9 in GMR-1 05.008 [7].
10 Radio link measurements
Same as clause 10 in GMR-1 05.008 [7].
11 Control parameters
Same as clause 11 in GMR-1 05.008 [7].
12 GMPRS mode tasks
12.1 GMPRS spot beam selection and reselection
12.1.1 BCCH type identification
For the purpose of MES idle mode operation, the MES shall be able to identify BCCH type. The BCCH can be either an
Anchored BCCH (A-BCCH) or Temporary BCCH (T-BCCH).
An Anchor BCCH (A-BCCH) shall have the following features:
1) It shall use an ARFCN on the BCCH_FULL_LIST for the serving satellite.
2) It shall be illuminated permanently in a satellite system.
3) It shall always be transmitted with full BCCH power.
4) It may be listed on a neighbor BCCH list.
5) It may be used for RSSI based spot beam selection.
A Temporary BCCH (T-BCCH)shall have the following features:
1) It may use any frequency, i.e., it may be assigned to an ARFCN not given in the BCCH_FULL_LIST for the
serving satellite.
2) It may not be illuminated or activated all the time.
3) It may not be transmitted with full BCCH power.
4) It shall not be listed in the neighbor BCCH list.
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GMPRS-1 05.008 12 ETSI TS 101 376-5-6 V2.3.1 (2008-08)

5) It shall not be used for RSSI based spot beam selection.
The BCCH type differentiation shall be based on the BCCH_Type_Flag (see GMPRS-1 04.008 [3]) decoded from the
System Information (SI).
12.1.2 Spot beam selection
GMPRS spot beam selection shall operate according to clause 7.
12.1.3 Spot beam reselection
The spot beam reselection shall operate as described in clause 7.7 of GMR-1 05.008 [7].
12.2 Idle mode link loss
If an MES is camped on a T-BCCH, the MES shall check T-BCCH availability by receiving at least one burst every
multiframe either from the PCH or the BCCH. If the MES is unable to read either the BCCH or PCH for 4 consecu
...