ETSI TS 101 376-3-22 V2.3.1 (2008-08)

GEO-Mobile Radio Interface Specifications (Release 2); General Packet Radio Service; Part 3: Network specifications; Sub-part 22: Overall description of the GMPRS radio interface; Stage 2; GMPRS-1 03.064

RTS/SES-00303-3-22

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)

Technical Specification
GEO-Mobile Radio Interface Specifications (Release 2)
General Packet Radio Service;
Part 3: Network specifications;
Sub-part 22: Overall description of
the GMPRS radio interface;
Stage 2;
GMPRS-1 03.064
GMPRS-1 03.064 2 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

Reference
RTS/SES-00303-3-22
Keywords
GMPRS, GMR, GPRS, GSM, GSO, mobile,
MSS, radio, satellite, S-PCN
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ETSI
GMPRS-1 03.064 3 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

Contents
Intellectual Property Rights.6
Foreword.6
Introduction .7
1 Scope.9
2 References.10
2.1 Normative references.10
2.2 Informative references.11
3 Definitions, symbols and abbreviations .12
3.1 Definitions.12
3.2 Symbols.12
3.3 Abbreviations.12
4 Packet data logical channels.12
4.1 General.12
4.2 Packet Common Control Channel (PCCCH) .12
4.2.1 Packet Random Access Channel (PRACH) - uplink only .13
4.2.2 Packet Paging Channel (PPCH) - downlink only .13
4.2.3 Packet Access Grant Channel (PAGCH) - downlink only.13
4.2.4 Packet Notification Channel (PNCH) and compact packet notification channel - downlink only .13
4.3 Packet Broadcast Control Channel (PBCCH) - downlink only.13
4.4 Packet traffic channels.13
4.4.1 Packet Data Traffic Channel (PDTCH) .13
4.5 Packet dedicated control channels.13
4.5.1 Packet Associated Control Channel (PACCH).13
4.5.2 Packet Timing Advance Control Channel, Uplink (PTCCH/U) .13
4.5.3 Packet Timing Advance Control Channel, Downlink (PTCCH/D) .14
5 Mapping of packet data logical channels onto physical channels.14
5.1 General.14
5.2 Packet Common Control Channels (PCCCH).14
5.2.1 Packet Random Access Channel (PRACH).14
5.2.1.1 PRACH on the same carrier.14
5.2.1.2 PRACH on a separate carrier .15
5.2.2 Packet Paging Channel (PPCH).15
5.2.3 Packet Access Grant Channel (PAGCH) .15
5.2.4 Packet Notification Channel (PNCH).15
5.3 Packet Broadcast Control Channel (PBCCH) .15
5.3.1 Compact Frequency Correction Channel (CFCCH) .15
5.3.2 Compact Synchronization Channel (CSCH).15
5.4 Packet Timing Advance Control Channel (PTCCH).15
5.5 Packet traffic channels.16
5.5.1 Packet Data Traffic Channel (PDTCH) .16
5.5.2 Packet Associated Control Channel (PACCH).16
5.6 Downlink resource sharing.16
5.7 Uplink resource sharing.16
5.8 Asymmetrical Pairing of PDCH/D(2,m) with PDCH/U(1,m).17
6 Radio interface (Um).17
6.1 Radio resource management principles.17
6.1.1 Allocation of resources for GMPRS-1.17
6.1.1.1 Master-slave concept.17
6.1.1.2 Capacity on demand concept.17
6.1.1.3 Procedures to support capacity on demand .18
6.1.1.4 Release of PDCH not carrying PCCCH .18
6.1.2 Multiframe structure for PDCH.18
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GMPRS-1 03.064 4 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

6.1.2.1 Multiframe structure for compact PDCH.19
6.1.3 Scheduling of PBCCH information .19
6.1.4 SMS cell broadcast .19
6.2 Radio resource operating modes .19
6.2.1 Packet idle mode.19
6.2.2 Packet transfer mode.19
6.2.3 Correspondence between radio resource operating modes and mobility management states.19
6.3 Layered overview of radio interface.20
6.4 Physical RF layer.20
6.5 Physical link layer .21
6.5.1 Layer services.21
6.5.2 Layer functions.21
6.5.3 Service primitives.22
6.5.4 Radio burst structure.22
6.5.5 Channel coding.23
6.5.5.1 Channel coding for PDTCH.23
6.5.5.1.1 Channel coding for PDTCH .23
6.5.5.2 Channel coding for PACCH, PAGCH and PTCCH.27
6.5.5.2.1 Channel coding for CPBCCH, CPAGCH, CPPCH, CPNCH, and CSCH.27
6.5.5.3 Channel coding for the PRACH.27
6.5.5.3.1 Coding of the 64 data bit packet access burst.27
6.5.5.3.2 Coding of the 11 data bit packet access burst.28
6.5.6 Spotbeam reselection.28
6.5.6.1 Measurements for spotbeam reselection .28
6.5.6.2 Broadcast information.28
6.5.6.3 Optional measurement reports and network controlled cell reselection.28
6.5.7 Timing and frequency update procedure .28
6.5.7.1 Initial timing advance estimation .28
6.5.7.2 Continuous timing and frequency update procedure.28
6.5.7.2.1 Mapping on the multiframe structure .29
6.5.8 Power control procedure.29
6.5.8.1 MES output power .29
6.5.8.2 BSS output power .30
6.5.8.3 Measurements at MES side.30
6.5.8.3.1 Deriving the C value.30
6.5.8.3.2 Derivation of channel quality report.30
6.5.8.4 Measurements at BSS side .30
6.5.9 Scheduling the MES activities during the PTCCH and idle frames.30
6.5.10 Discontinuous Reception (DRX) .30
6.5.11 Rate adaptation.30
6.5.12 UpLink Quality Reports.30
6.6 Medium access control and radio link control layer.31
6.6.1 Layer services.31
6.6.2 Layer functions.31
6.6.3 Service primitives.32
6.6.4 Mode of operation.32
6.6.4.1 Multiplexing MESs on the same PDCH.33
6.6.4.1.1 Uplink state flag: dynamic allocation.33
6.6.4.1.2 Fixed allocation.33
6.6.4.2 Temporary block flow.33
6.6.4.2.1 Support for Streaming traffic.33
6.6.4.3 Temporary flow identity.34
6.6.4.4 Medium access modes.34
6.6.4.5 Acknowledged mode for RLC/MAC operation .34
6.6.4.5.1 GMPRS-1.34
6.6.4.6 Unacknowledged mode for RLC/MAC operation .34
6.6.4.7 Mobile originated packet transfer .35
6.6.4.7.1 Uplink access.35
6.6.4.7.2 Dynamic allocation.36
6.6.4.7.3 Fixed allocation.36
6.6.4.7.4 Contention resolution.36
6.6.4.7.5 Piggybacked messages and unsolicited resource grant.37
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GMPRS-1 03.064 5 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

6.6.4.8 Mobile terminated packet transfer.37
6.6.4.8.1 Packet paging.37
6.6.4.8.2 Downlink packet transfer.38
6.6.4.8.3 Release of the resources .39
6.6.4.9 Simultaneous uplink and downlink packet transfer.39
6.7 Abnormal cases in MES ready state.40
6.8 PTM-M data transfer .40
Annex A (informative): Bibliography.41
History .42

ETSI
GMPRS-1 03.064 6 ETSI TS 101 376-3-22 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 3, sub-part 22 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":
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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GMPRS-1 03.064 7 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

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";
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 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.
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GMPRS-1 03.064 8 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

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 TS 101 376-1-2 [10].
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GMPRS-1 03.064 9 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

1 Scope
The present document provides the overall description for lower-layer functions of the GEO-Mobile Packet Radio
Service (GMPRS-1) radio interface (Um).
The overall description provides the following information:
- The services offered to higher-layer functions.
- The distribution of required functions into functional groups.
- A definition of the capabilities of each functional group.
- Service primitives for each functional group, including a description of what services and information flows
are to be provided;
- A model of operation for information flows within and between the functions.
The present document is applicable to the following GMPRS-1 Um functional layers:
- Radio Link Control functions.
- Medium Access Control functions
- Physical Link Control functions.
The present document describes the information transfer and control functions to be used across the radio (Um)
interface for communication between the MES and the Network (see figure 1).
Um
MT Network
Figure 1: Scope of GMPRS-1 logical radio interface architecture
The overall GMPRS-1 logical architecture and the GMPRS-1 functional layers above the Radio Link Control and
Medium Access Control layer are the same as GSM/GPRS as described in TS 101 344 [3].
GMPRS-1 04.007 [5] contains a description in general terms of the structured functions and procedures of this protocol
and the relationship of this protocol with other layers and entities.
TS 101 376-4-8 [6] contains the definition of GMPRS-1 RLC/MAC procedures when operating on the Common
Control Channel (CCCH).
TS 101 376-4-12 [7] contains the definition of RLC/MAC functions when operating on a Packet Data Channel (PDCH).
The functional procedures for the Logical Link Control (LLC) layer above the RLC/MAC are the same as GSM/GPRS
as described in TS 101 351 [8].
GMR-1 05-series defines the Physical Link layer and Physical RF layer (see [11] to [17]).
ETSI
GMPRS-1 03.064 10 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

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 EN 301 113: "Digital cellular telecommunications system (Phase 2+) (GSM); General
Packet Radio Service (GPRS); Service description; Stage 1 (GSM 02.60 version 6.3.1 Release
1997)".
[3] ETSI TS 101 344: "Digital cellular telecommunications system (Phase 2+); General Packet Radio
Service (GPRS) Service description; Stage 2". (3GPP TS 03.60 Release 1997).
[4] ETSI TS 101 376-4-4: "GEO-Mobile Radio Interface Specifications; Part 4: Radio interface
protocol specifications; Sub-part 4: Layer 1 General Requirements; GMR-1 04.004".
NOTE: This is a reference to a GMR-1 Release 1 specification. See the introduction for more details.
[5] ETSI TS 101 376-4-7: "GEO-Mobile Radio Interface Specifications (Release 2) General Packet
Radio Service; Part 4: Radio interface protocol specifications; Sub-part 7: Mobile Radio Interface
Signalling Layer 3 General Aspects; GMPRS-1 04.007".
[6] 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".
[7] 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".
ETSI
GMPRS-1 03.064 11 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

[8] ETSI TS 101 351: "Digital cellular telecommunications system (Phase 2+); General Packet Radio
Service (GPRS); Mobile Station - Serving GPRS Support Node (MS-SGSN) Logical Link Control
(LLC) layer specification". (3GPP TS 04.64 Release 1997).
[9] ETSI TS 101 297: "Digital cellular telecommunications system (Phase 2+) (GSM); General Packet
Radio Service (GPRS); Mobile Station (MS) - Serving GPRS Support Node (SGSN); Subnetwork
Dependent Convergence Protocol (SNDCP)". (GSM 04.65 Release 1997)".
[10] 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".
[11] ETSI TS 101 376-5-1: "GEO-Mobile Radio Interface Specifications (Release 1); Part 5: Radio
interface physical layer specifications; Sub-part 1: Physical Layer on the Radio Path: General
Description; GMR-1 05.001".
NOTE: This is a reference to a GMR-1 Release 1 specification. See the introduction for more details.
[12] ETSI TS 101 376-5-2: "GEO-Mobile Radio Interface Specifications (Release 2) General Packet
Radio Service; Part 5: Radio interface physical layer specifications; Sub-part 2: Multiplexing and
Multiple Access; Stage 2 Service Description; GMPRS-1 05.002".
[13] 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".
[14] ETSI TS 101 376-5-4: "GEO-Mobile Radio Interface Specifications (Release 2) General Packet
Radio Service; Part 5: Radio interface physical layer specifications; Sub-part 4: Modulation;
GMPRS-1 05.004 ".
[15] 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".
[16] ETSI TS 101 376-5-6: "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".
[17] 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".
[18] 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".
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.
ETSI
GMPRS-1 03.064 12 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in TS 101 376-1-2 [10] apply.
GMPRS-1 also uses some GSM definitions and the relevant GSM/GPRS specific definitions can be found in
EN 301 113 [2] and TS 101 344 [3].
3.2 Symbols
For the purposes of the present document, the following symbols apply:
Gb Interface between an SGSN and a BSC.
Um Interface between MES and GMPRS-1 fixed network part. The Um interface is the GMPRS-1
network interface for providing packet data services over the radio to the MES.
3.3 Abbreviations
For the purposes of the present document, the abbreviations given in TS 101 376-1-1 [1] apply.
4 Packet data logical channels
NOTE: The text in this clause is informative. The normative text is in TS 101 376-5-2 [12]. Where there is a
conflict between these descriptions, the normative text has precedence.
4.1 General
This clause describes the packet data logical channels that are supported by the radio subsystem. The packet data logical
channels are mapped onto the physical channels that are dedicated to packet data.
The physical channel dedicated to packet data traffic is called a Packet Data Channel (PDCH). A PDCH can carry
common control channel (PCCCH) with the data and dedicated control channels.
Packet channels are defined in GMR-1 for 125 kHz and for 156,25 kHz carriers, which are each three time-slots or
twelve time-slots wide. Packet channels are also defined for uplink 31,25 kHz carriers and downlink 62,5 kHz carriers,
which are six timeslots wide. Timeslots are defined in TS 101 376-5-2 [12].
In the context of RLC/MAC and other higher layers, the term MAC-slot is used to define a triad of timeslots containing
a single Packet Access Burst or Packet Normal Burst. Thus there can be eight packet channels or one or more CCCH
and packet channels carrying PCCCH in a 24 slot (8 MAC-slot) frame. The term 4-MAC-slot is used to define four
consecutive MAC slots or twelve consecutive timeslots. The starting MAC-slot of a 4-MAC-slot can be any one of the
eight MAC-slots in a frame. Depending on the starting MAC-slot, a 4-MAC-slot may span two consecutive frames.
An additional term is defined, which is the dual MAC-slot abbreviated as D-MAC-slot. A D-MAC-slot represents two
consecutive MAC slots or six consecutive timeslots. A D-MAC slot k ( 0 ≤ k ≤ 3 ) can be defined as a combination of
MAC-slot 2k and MAC-slot 2k + 1.
4.2 Packet Common Control Channel (PCCCH)
PCCCH comprise logical channels for common control signalling used for packet data as described in the following
clauses.
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GMPRS-1 03.064 13 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

4.2.1 Packet Random Access Channel (PRACH) - uplink only
PRACH is used by MES to initiate uplink transfer for sending data or signalling information. Packet Access burst is
used on PRACH.
4.2.2 Packet Paging Channel (PPCH) - downlink only
PPCH is not supported in the GMR-1 standard.
4.2.3 Packet Access Grant Channel (PAGCH) - downlink only
PAGCH is used in the packet transfer establishment phase to send resource assignment to an MES prior to packet
transfer.
4.2.4 Packet Notification Channel (PNCH) and compact packet notification
channel - downlink only
These logical channels are currently not supported.
4.3 Packet Broadcast Control Channel (PBCCH) - downlink
only
This logical channel is currently not supported.
For details of system information transmission for the GMR-1 Release 2 air interface supporting packet data, refer to
TS 101 376-4-8 [6] for details.
4.4 Packet traffic channels
4.4.1 Packet Data Traffic Channel (PDTCH)
PDTCH is a channel allocated for data transfer. In the multislot operation, one MES may use multiple PDTCHs in
parallel for individual packet transfer.
All packet data traffic channels are uni-directional, either uplink (PDTCH/U), for a mobile originated packet transfer or
downlink (PDTCH/D) for a mobile terminated packet transfer.
4.5 Packet dedicated control channels
4.5.1 Packet Associated Control Channel (PACCH)
PACCH conveys signalling information related to a given MES. The signalling information includes examples of
acknowledgments and power control information. PACCH also carries resource assignment and reassignment
messages, comprising the assignment of a capacity for PDTCH(s) and for further occurrences of PACCH. The PACCH
shares resources with PDTCHs that are currently assigned to one MES.
4.5.2 Packet Timing Advance Control Channel, Uplink (PTCCH/U)
PTCCH/U is used to transmit packet normal burst to allow estimation of the timing advance for one MES in packet
transfer mode.
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GMPRS-1 03.064 14 ETSI TS 101 376-3-22 V2.3.1 (2008-08)

4.5.3 Packet Timing Advance Control Channel, Downlink (PTCCH/D)
PTCCH/D is used to transmit timing advance information updates to several MES. One PTCCH/D is paired with up to
four PTCCH/Us. PTCCH/D is only transmitted on MAC slot 0.
5 Mapping of packet data logical channels onto
physical channels
NOTE: The text in this clause is informative. The normative text is in TS 101 376-5-2 [12]. Where there is a
conflict between these descriptions, the normative text has precedence.
5.1 General
Different packet data logical channels can occur on the same physical channel (PDCH). The sharing of the physical
channel is based on MAC-slots, each of which corresponds to a single burst. The mapping in frequency of PDCH on to
the physical channel shall be as defined in TS 101 376-5-2 [12].
On PRACH, packet access bursts are used. On all other packet data logical channels, MAC/RLC blocks comprising a
single Packet Normal Burst PNB(m, n) or PNB2(m,n) is used, corresponding to the PDCH on which the logical channel
is allocated.
5.2 Packet Common Control Channels (PCCCH)
At a given time, the logical channels of the PCCCH are mapped on different physical resources than the logical
channels of the CCCH.
The PCCCH does not have to be allocated permanently in the cell.
One given MES may use only a subset of the PCCCH, the subset being mapped onto one physical channel (PDCH).
The PCCCH, when it exists, is mapped on one or several physical channels according to a 16-multiframe; in that case
the PCCCH and PDTCH share the same physical channels (PDCHs).
The existence and location of the PCCCH shall be broadcast on the BCCH in the spotbeam. The BCCH identifies each
frequency that carries the PCCCH and further information which helps the MES access the PCCCH.
5.2.1 Packet Random Access Channel (PRACH)
The PRACH is mapped on one or several physical channels. The physical channels on which the PRACH is mapped are
derived by the MES from information broadcast on the BCCH.
The MES can send a PRACH to the network in the following two ways as described in clauses 5.2.1.1 and 5.2.1.2.
5.2.1.1 PRACH on the same carrier
PRACH is determined by the Uplink State Flag, marked as "free," that is broadcast continuously on the corresponding
downlink (see clause 6.6.4.1).
Since the PRACH uses a bandwidth of only 31,25 kHz, whereas the PDCH uses bandwidths that are n × 31,25 kHz
(n = 2, 4, 5, 6), it is possible to overlay multiple PRACH slots over a single unused PDCH slot, with each PRACH slot
using one 31,25 kHz chunk of the PDCH bandwidth. The BCCH system information parameter PRACH_OVERLAY
indicates whether this feature is supported or not. If this feature is supported, the system information parameter
PRACH_OVERLAY_CHAN indicates the maximum number of PRACHs that may be overlaid on a single PDCH slot;
i.e. even if n is set to 6, the number of overlaid PRACH slots may be less, depending on the network capabilities and
PRACH demand. If multiple PRACH overlay is activated, the PRACH slots are allocated from the lower edge of the
sub-band (see TS 101 376-5-2 [12] for more details). The MES should randomly choose one of the overlaid frequencies
for transmission of the Packet Access Burst (PAB). In case of failure, the
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