ETSI TS 101 376-5-6 V3.2.1 (2011-02)

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; GMR-1 3G 45.008

RTS/SES-00315-5-6

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: 14-Mar-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 5: Radio interface physical layer specifications;
Sub-part 6: Radio Subsystem Link Control;
GMR-1 3G 45.008
GMR-1 3G 45.008 2 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

Reference
RTS/SES-00315-5-6
Keywords
3G, control, gateway, GMPRS, GMR, GPRS,
GSM, GSO, interface, MES, mobile, MSC, MSS,
radio, satellite, S-PCN
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ETSI
GMR-1 3G 45.008 3 ETSI TS 101 376-5-6 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 . 11
5 RF power control . 11
6 Radio link failure . 11
7 Idle mode tasks . 12
8 Network prerequisites. 12
8.1 BCCH carriers with FCCH . 12
8.2 BCCH carriers with FCCH3 . 12
9 Aspects of Discontinuous Transmission (DTX) . 12
9.1 Rules of burst transmission (A/Gb mode) . 12
9.2 Rules of burst transmission on a Dedicated CHannel (DCH) (Iu mode) . 13
10 Radio link measurements . 13
11 Control parameters . 13
12 GMPRS mode tasks . 14
12.1 GMPRS and GMR-1 3G spot beam selection and reselection . 14
12.1.1 BCCH type identification (A/Gb mode only) . 14
12.1.2 Spot beam selection . 14
12.1.3 Spot beam reselection . 14
12.2 Idle mode link loss (A/Gb model only) . 15
12.3 Link adaptation . 15
12.3.1 Objective and overall procedure . 15
12.3.2 Power control and link adaptation parameters . 15
12.3.3 PAN, FQI, SQIR, and SQISDR transmission . 16
12.3.3.1 Terminal Type A, C and D . 16
12.3.3.2 Terminal Type E and above . 16
12.3.4 PAR transmission . 16
12.3.4.1 Terminal Type A, C, and D . 16
12.3.4.2 Terminal Type E and above . 16
12.3.5 MES output power . 16
12.3.5.1 Terminal Type A, C, D, E and above . 16
12.3.5.2 Open-loop power control at a terminal type C MES . 17
12.3.5.2.1 Signal quality estimation . 17
12.3.5.2.2 Open-loop power control procedure . 17
12.3.6 GS output power . 18
12.3.7 Radio link measurements and accuracy requirements . 18
12.3.8 Signal Quality Indicator Report (SQIR) and Signal Quality Standard Deviation (SQISDR)
transmissions. 19
12.3.8a Forward Quality Indicator (FQI) transmissions . 21
12.3.9 Code rate adaptation . 21
ETSI
GMR-1 3G 45.008 4 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

12.3.9.1 Terminal type A . 22
12.3.9.2 Terminal type C . 22
12.3.9.3 Terminal type D . 22
12.3.9.4 Terminal type E and above. 23
12.4 UT Link Quality Report (UTLQR) handling. 23
12.5 Timing for the power level adjustment. 23
13 Idle Mode Tasks with FCCH3 . 23
13.1 Introduction . 23
13.2 Measurements for stored list spot beam selection . 24
13.3 All LMSS band carrier spot beam search . 24
13.4 Criteria for Spot Beam Selection and Reselection . 25
13.4.1 MES Capabilities and Operating Environment . 25
13.4.2 Position-Based Spot Beam Selection . 26
13.4.3 Power-Based Spot Beam Selection . 27
13.4.3.1 Spot Beam BCCH Power Comparison . 27
13.4.3.2 BCCH Flux Density Criterion (C1) . 28
13.5 Minimum Signal Strength for Transmission Via the RACH3 . 29
13.6 Spot beam reselection . 29
13.7 BCCH read operation . 29
13.8 Abnormal cases and emergency calls . 29
Annex A (informative): Pseudocode for power control . 31
Annex B (informative): Per-burst SQI estimation . 32
Annex C (informative): Position determination at the MES . 33
Annex D (informative): Bibliography . 34
History . 35

ETSI
GMR-1 3G 45.008 5 ETSI TS 101 376-5-6 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 5, sub-part 6 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";
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
GMR-1 3G 45.008 6 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

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.
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.
ETSI
GMR-1 3G 45.008 7 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

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 or 3GPP specifications are not subject to
this precedence rule. For example, a GMR or 3GPP 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 1 41.201 [9].
ETSI
GMR-1 3G 45.008 8 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

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 3G 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 GMR-1 3G 45.010 [6], and messages for timing
and frequency control are defined in GMR-1 3G 44.008 [3].
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 (GMPRS); 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 43.022 (ETSI TS 101 376-3-10): "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".
[3] 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".
[4] GMR-1 3G 45.003 (ETSI TS 101 376-5-3): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite Packet Radio Service; Part 5: Radio interface physical layer
specifications; Sub-part 3: Channel Coding".
[5] 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".
[6] 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".
ETSI
GMR-1 3G 45.008 9 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

[7] GMR-1 05.008 (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".
NOTE: This is a reference to a GMR-1 Release 1 specification. See the introduction for more details.
[8] GMR-1 3G 44.060 (ETSI TS 101 376-4-12): "GEO-Mobile Radio Interface Specifications
(Release 3); Third Generation Satellite 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".
[9] 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".
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.
Not applicable.
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 [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.
criterion C1: used by the MES for detecting the presence of the frequency control channel (FCCH) and switching out
of the frequency search state
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): parameter Olthresh is the threshold on the LQI estimate before activating open
loop power control
Open Loop Gain (Olgain): parameter Olgain is the loop gain for open loop control
ETSI
GMR-1 3G 45.008 10 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

Power Attenuation Notification (PAN): attenuation, in dB, used by the transmitter in the power control loop, relative
to the maximum transmit power level
Power Attenuation Request (PAR): 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
NOTE 1: 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 2: 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: System parameter for deriving the 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
Signal Quality Indication (SQI) or Signal Quality Measurement (SQM): 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.
ETSI
GMR-1 3G 45.008 11 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

3.2 Abbreviations
For the purposes of the present document, the abbreviations defined 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
TX Transmit
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 and when MES is operating in Iu mode with packet channel (PDCH)
allocation in downlink direction:
• 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 D and below 3,0 dB for terminal
s o
type C. The MES shall detect link failure by determining that the received E /N is below 2,5 dB for terminal
s o
type E and above. 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 GMR-1 3G 44.008 [3]), and the default value is 10 seconds.
• In case of the radio link failure detection, the MES shall perform the procedure specified in
GMR-1 3G 44.060 [8].
When MES is operating in Iu mode with dedicated channel (DCH) allocation in downlink direction, the radio link
failure criterion is based on a radio link failure counter S and the system information parameter
RADIO_LINK_TIMEOUT.
1) At the assignment of a dedicated channel (DCH), the MES shall initialize the radio link failure counter S to a
value of (RADIO_LINK_TIMEOUT × 25).
2) The MES shall never set the counter S to a value greater than (RADIO_LINK_TIMEOUT × 25). This
restriction shall be a limitation on all following paragraphs of this clause.
ETSI
GMR-1 3G 45.008 12 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

3) If a PNB3(1,n) data burst (DACCH) or PNB3(1,n) speech burst or KAB3 (1,n) burst is received, the power
control Golay code shall provide the criterion for judging the quality of the radio link. The Golay decoder,
besides decoding the power control field, shall also perform error detection check. If this check passes, the
counter S shall be incremented by 6, otherwise the counter S shall be decremented by 6. The MES shall have a
full block of 6 consecutive frames to either increment or decrement S. In the event that the power control
message framing has not been determined (i.e. synchronization is not achieved), a Golay decoding failure shall
be assumed every 240 ms.
4) If S reaches 0, radio link failure shall be declared by the MES. In case of radio link failure, the MES shall be
required to perform the procedure specified in GMR-1 3G 44.160 [8].
5) The counter S shall be reinitialized to (RADIO_LINK_TIMEOUT × 25) at dedicated channel reassignment.
7 Idle mode tasks
Same as clause 7 in GMR-1 05.008 [7], with the following modifications:
• For terminals using FCCH3 bursts, clause 13 of the present document shall apply.
8 Network prerequisites
8.1 BCCH carriers with FCCH
Same as clause 8 in GMR-1 05.008 [7].
8.2 BCCH carriers with FCCH3
When the FCCH3 is used, the network shall transmit two twelve-timeslot FCCH3s into every multiframe on a PC12d
physical channel. The BCCH using a twelve-timeslot DC12 burst shall be transmitted once every eight frames in the
second frame, following the FCCH3. All other control channels, e.g. the PCH, AGCH, and GBCH3 are time
multiplexed onto this physical channel using a DC12 burst.
The BCCH carriers in adjacent spot beams shall have their transmission of FCCH3 and BCCH offset in time, either on
different timeslots or on the same timeslot, but offset in frame number to facilitate the signal strength and quality
measurements at the MES for spot beam selection and reselection. The neighbouring beams' BCCH carrier
identification and the timing shall be broadcast in the BCCH.
9 Aspects of Discontinuous Transmission (DTX)
Same as clause 9 in GMR-1 05.008 [7].
9.1 Rules of burst transmission (A/Gb mode)
This clause only applies to MES operating in A/Gb mode.
Same as clause 9.1 in GMR-1 05.008 [7].
ETSI
GMR-1 3G 45.008 13 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

9.2 Rules of burst transmission on a Dedicated CHannel (DCH)
(Iu mode)
This clause only applies to MES operating in Iu mode.
The rules for burst transmission of a Dedicated CHannel (DCH) are:
1) At the PHY layer, burst transmissions on a DCH shall be continuous (every frame) from the time the channel
is setup until it is released. The continuous transmissions shall be comprised of either upper layer voice, data
or control traffic bursts, or PHY layer KAB3 keep alive bursts.
2) Two transmission phases shall be defined on an assigned DCH: i) an initialization phase in which the upper
layer provides data bursts for transmission in every TDMA frame, and, ii) a normal operating phase in which
the upper layer is only required to ensure that upper layer bursts (voice, data or control) are provided for
transmission no less frequently than once every 25 frames (1 second).
i) The initialization phase shall extend for a period of 50 frames (2 seconds) from the time that the DCH is
assigned. During the initialization phase only upper layer data bursts at a single MCS-defined
transmission rate shall be transmitted on the DCH. The data transmission rate will be based on the
channel type established on the DCH. Burst classification at the PHY layer shall therefore be restricted to
a single data burst type, as specified by the upper layer (RLC/MAC), for the entire 50-frame initialization
period. During the initialization phase all bursts shall be transmitted at maximum power.
ii) The normal operating phase shall immediately follow the initialization phase and continue until the DCH
is released. During the normal operating phase the upper layer shall provide voice, data or control traffic
bursts for transmission at least once per 25 frames. The upper layer will provide dummy control bursts
when there is no other upper layer traffic bursts to send on the channel. Once the requirement of one
upper layer transmission burst per second is met, KAB3 keep alive bursts shall be transmitted when there
are no other voice, data or control traffic bursts arriving for transmission. Burst classification at the PHY
layer during the normal operating phase shall be based on the upper layer traffic types supported on the
DCH. During the normal operating phase bursts shall be transmitted at a power level derived by the link
adaptation power control applicable to the services supported on the channel.
10 Radio link measurements
Same as clause 10 in GMR-1 05.008 [7] with the following additions:
Table10.3: SQI Estimation Accuracy for DC12 burst
j
Actual E /N (dB) Standard deviation of measurement
bt o
error (dB)
-3 1
0 1
3 0,4
6 0,4
9 0,4
12 0,4
The SQM estimation bias at E /N of -3 dB shall not exceed 0,5 dB.
bt o
11 Control parameters
Same as clause 11 in GMR-1 05.008 [7].
ETSI
GMR-1 3G 45.008 14 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

12 GMPRS mode tasks
12.1 GMPRS and GMR-1 3G spot beam selection and
reselection
12.1.1 BCCH type identification (A/Gb mode only)
This clause only applies to MES operating in A/Gb mode.
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 neighbour 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 neighbour BCCH list.
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 GMR-1 3G 44.008 [3]) decoded from the
System Information (SI).
12.1.2 Spot beam selection
For terminals using FCCH spot beam selection shall operate according to clause 7 of GMR-1 05.008 [7]. For terminals
using FCCH3 spot beam selection shall operate according to clause 13.
12.1.3 Spot beam reselection
For terminals using FCCH spot beam reselection shall operate according to clause 7.7 of GMR-1 05.008 [7]. For
terminals using FCCH3 spot beam selection shall operate according to clause 13.
ETSI
GMR-1 3G 45.008 15 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

12.2 Idle mode link loss (A/Gb model only)
This clause only applies to MES operating in A/Gb mode.
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 consecutive
multiframes, the MES shall switch to one of the concurrent A-BCCHs. It shall then camp on the A-BCCH or any
A-BCCH with the same spot beam ID as the dark T-BCCH. While camped on an A-BCCH in the same spot beam as the
T-BCCH, the MES shall periodically read the system information broadcast on the A-BCCH as described in clause 7.10
of GMR-1 05.008 [7]. If the concurrent list changes or if the MES reacquires the T-BCCH, it shall follow the
procedures in GMR-1 3G 43.022 [2].
The BCCH read operation of clause 7.10, of GMR-1 05.008 [7], shall apply to a MES camped on a T-BCCH or an
A-BCCH in GMPRS mode.
12.3 Link adaptation
12.3.1 Objective and overall procedure
The objective of the link adaptation is to optimize the transmission throughput according to each user's channel
environment while a reliable transmission is guaranteed.
For the forward link transmission to terminal type A, the code rate of the encoder is determined at the TBF initialization
and is unchanged during the corresponding TBF. Note that the TX power level at the GS is not changed for the purpose
of the forward link adaptation.
For the return link transmission from terminal type A, the code rate of the encoder and the initial TX power level of the
MES are determined at the TBF initialization. While the code rate remains unchanged, the TX power level of the MES
is adaptively controlled during the corresponding TBF.
For the forward link transmission to terminal type C, the code rate of the encoder at the GS may be adaptively
controlled during the TBF. Note that the TX power level at the GS is not changed for the purpose of the forward link
adaptation.
For the return link transmission from terminal type C, the code rate of the encoder and the initial TX power level of the
MES are determined at the TBF initialization. Subsequently, the GS may adaptively change both the code rate and the
TX power level during a TBF.
For the forward link transmission to terminal type D, the code rate and modulation of the encoder at the GS may be
adaptively controlled during the TBF. Note that the TX power level at the GS is not changed for the purpose of the
forward link adaptation.
For the return link transmission from terminal type D, the code rate and modulation of the encoder and the initial TX
power level of the MES are determined at the TBF initialization. Subsequently, the GS may adaptively change both the
code rate and the TX power level during a TBF.
For the forward link transmission to terminal types E and above the code rate and modulation of the encoder at the GS
may be adaptively controlled during the TBF. Note that the TX power level at the GS is not changed for the purpose of
the forward link adaptation, except for a DCH.
For the return link transmission from terminal types E and above the code rate and modulation of the encoder and the
initial TX power level of the MES are determined at the TBF initialization. Subsequently, the GS may adaptively
change both the code rate and the TX power level during a TBF.
12.3.2 Power control and link adaptation parameters
Power control and link adaptation requires five variables: PAR and PAN that are defined in clauses 5.3.1 and 5.3.2 of
GMR-1 05.008 [7], FQI, SQIR and SQISDR. PAR is created by the GS and sent to the corresponding MES. PAN, FQI,
SQIR, and SQISDR are created by the MES and sent to the GS.
ETSI
GMR-1 3G 45.008 16 ETSI TS 101 376-5-6 V3.2.1 (2011-02)

12.3.3 PAN, FQI, SQIR, and SQISDR transmission
12.3.3.1 Terminal Type A, C and D
The PAN is transmitted on PUblic Information (PUI). Refer to GMR-1 3G 44.060 [8] for radio block and Ieformat. The
PAN value shall indicate the actual power level used to send this radio block. The PAN is transmitted on every
transmitted radio block.
12.3.3.2 Terminal Type E and above
In the case of a DCH, the UT shall transmit three values to the GS: the FQI or the forward quality indicator that
represents the Boolean CRC indicator for a burst received at the UT (FQI=1 indicates that CRC has passed, FQI=0
indicates that CRC has failed), the SQIR or the mean of its SQM and the PAN, which is the relative power at which the
UT transmitted. The 1 bit FQI is sent to the GS every burst. The SQIR and the PAN are each encoded into a 6 bit
words, PAN occupies the least significant 6 bits and SQIR occupies the most significant s
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