ETSI EN 302 404 V7.1.1 (2000-08)
Digital cellular telecommunications system (Phase 2+) (GSM); GSM Cordless Telephony System (CTS), Phase 1; Lower Layers of the CTS Radio Interface; Stage 2; (GSM 03.52 version 7.1.1 Release 1998)
Digital cellular telecommunications system (Phase 2+) (GSM); GSM Cordless Telephony System (CTS), Phase 1; Lower Layers of the CTS Radio Interface; Stage 2; (GSM 03.52 version 7.1.1 Release 1998)
DEN/SMG-030352Q7
Digitalni celični telekomunikacijski sistem (faza 2+) – GSM sistem brezvrvične telefonije (CTS) – Faza 1 – Spodnje plasti radiskega vmesnika za CTS – Stopnja 2 (GSM 03.52, različica 7.1.1, izdaja 1998)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2003
'LJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHP ID]D ±*60VLVWHPEUH]YUYLþQH
WHOHIRQLMH &76 ±)D]D±6SRGQMHSODVWLUDGLVNHJDYPHVQLND]D&76±6WRSQMD
*60UD]OLþLFDL]GDMD
Digital cellular telecommunications system (Phase 2+) (GSM); GSM Cordless Telephony
System (CTS), Phase 1; Lower Layers of the CTS Radio Interface; Stage 2; (GSM 03.52
version 7.1.1 Release 1998)
Ta slovenski standard je istoveten z: EN 302 404 Version 7.1.1
ICS:
33.070.50 Globalni sistem za mobilno Global System for Mobile
telekomunikacijo (GSM) Communication (GSM)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
European Standard (Telecommunications series)
Digital cellular telecommunications system (Phase 2+);
GSM Cordless Telephony System (CTS), Phase 1;
Lower Layers of the CTS Radio Interface;
Stage 2
(GSM 03.52 version 7.1.1 Release 1998)
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
2 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
Reference
DEN/SMG-030352Q7
Keywords
Digital cellular telecommunications system,
Global System for Mobile communications
(GSM),GSM Cordless Telephony System (CTS)
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.:+33492944200 Fax:+33 493654716
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
Individual copies of the present document can be downloaded from:
http://www.etsi.org
The present document may be made available in more than one electronic version or in print. In any case of existing or
perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF).
In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive
within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at http://www.etsi.org/tb/status/
If you find errors in the present document, send your comment to:
editor@etsi.fr
Copyright Notification
No part may be reproduced except as authorized by written permission.
The copyright and the foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 2000.
All rights reserved.
ETSI
3 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
Contents
Intellectual Property Rights.6
Foreword.6
1 Scope .7
2 References .7
3 Definitions and abbreviations.8
3.1 Definitions.8
3.2 Abbreviations .8
4 Main concepts of the CTS radio interface.8
4.1 Beacon concept .8
4.2 Adaptive Frequency Allocation (AFA) concept.9
4.3 Total Frequency Hopping (TFH) concept .9
5 Radio Transmission and Reception.9
5.1 Frequency Band and Channel Arrangement.9
5.2 Receiver Characteristics .9
5.2.1 CTS-MS characteristics .9
5.2.2 CTS-FP characteristics .9
5.3 Transmitter Characteristics.9
5.3.1 CTS-MS characteristics .9
5.3.2 CTS-FP characteristics .10
5.4 CTS transmitter / receiver performance .10
6 Modulation and Raw Data Rates.10
7 Channel Coding and Interleaving.10
8 Time Slots and TDMA-Frames.10
9 Bursts.11
10 Logical Channels.11
10.1 CTS Beacon Channel (CTSBCH) .11
10.1.1 CTSBCH format .11
10.1.2 CTSBCH timing .11
10.1.3 CTSBCH radio frequency channel .12
10.1.4 CTSBCH-SB information.12
10.2 CTS Access Request Channel (CTSARCH) .12
10.2.1 CTSARCH format .12
10.2.2 CTSARCH timing .12
10.2.3 CTSARCH radio frequency channel.12
10.2.4 CTSARCH information .13
10.3 CTS Access Grant Channel (CTSAGCH).13
10.3.1 CTSAGCH format .13
10.3.2 CTSAGCH timing .13
10.3.3 CTSAGCH radio frequency channel .13
10.3.4 CTSAGCH information.13
10.4 CTS Paging Channel (CTSPCH).14
10.4.1 CTSPCH format.14
10.4.2 CTSPCH timing.14
10.4.3 CTSPCH radio frequency channel.14
10.4.4 CTSPCH information .14
10.5 SACCH .14
10.6 FACCH .15
10.7 TCH.15
10.8 Mapping of the Logical Channels onto Physical Channels .15
10.8.1 Mapping in time of the logical channels onto the physical channels.15
ETSI
4 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
10.8.2 Mapping in frequency of the logical channels onto the physical channels .16
10.8.3 Permitted Channel Combinations .16
11 Lower Layer Procedures .17
11.1 CTSBCH transmission .17
11.2 CTSBCH timeslot management .17
11.3 CTSBCH-FB detection.17
11.4 CTSBCH-SB decoding.17
11.5 Discontinuous transmission (DTX).17
11.6 Interference measurements.17
11.7 MS timing offset measurements.18
12 Radio Resource Management Procedures.18
12.1 Radio Resources management states.18
12.2 General procedures.18
12.2.1 Initial synchronization of a CTS-MS and CTS-FP .18
12.2.2 Frequency management .18
12.2.2.1 Interference measurements exchange.19
12.2.2.2 Adaptive Frequency Allocation (AFA) algorithm .19
12.2.2.3 AFA / TFH interworking .19
12.2.2.4 CTSBCH frequency selection .19
12.2.3 CTSBCH-SB information.20
12.2.4 Control of CTS-FP service range.20
12.2.5 CTS-FP selection .20
12.3 RR Idle state procedures.20
12.3.1 CTSBCH monitoring .20
12.3.2 Alive check .20
12.3.3 Establishment of a dedicated RR connection.20
12.3.3.1 Timeslot assignment for dedicated connection .20
12.3.3.2 CTS-MS initiated RR connection establishment.21
12.3.3.2.1 Non-hopping access procedure.21
12.3.3.2.2 Hopping access procedure.21
12.3.3.3 CTS-FP initiated RR connection establishment .21
12.3.4 CTSBCH failure detection.22
12.4 RR Active state procedures .22
12.4.1 Radio link failure detection.22
12.4.2 RF power control .22
12.4.3 Intracell handover .22
12.4.4 Channel release.22
Annex A (informative): GSM backwards compatibility issues .23
A.1 Reasons for possible impact of a CTS-FP on a GSM-MS in the PLMN .23
A.1.1 Power measurement of BCCH carrier.23
A.1.1.1 Power on CTS-FP beacon frequency seen by the GSM-MS in cell selection.23
A.1.1.2 Power on CTS-FP hopping frequencies seen by the GSM-MS in cell selection .24
A.1.2 Synchronisation of a GSM-MS .24
A.2 Scenario 1: PLMN and CTS-GFL have no common frequency in whole coverage area.24
A.2.1 Cell Selection .24
A.2.1.1 GSM-MS has no BA list stored on the SIM .24
A.2.1.2 GSM-MS has a stored BA list on the SIM (optional).24
A.2.2 Cell reselection.25
A.2.3 Handover .25
A.3 Scenario 2: PLMN and CTS-GFL have locally no common frequency.25
A.3.1 Cell Selection .25
A.3.1.1 GSM-MS has no BA list stored on the SIM .25
A.3.1.2 GSM-MS has a stored BA list on the SIM (optional).25
A.3.2 Cell reselection.25
A.3.2.1 GSM-MS camping on its home PLMN .25
A.3.2.2 GSM-MS camping on a visited PLMN in home country.26
A.3.3 Handover .26
ETSI
5 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
A.4 Scenario 3: PLMN and CTS-GFL have locally some common frequencies.26
A.4.1 Cell selection .26
A.4.2 Cell reselection.26
A.4.3 Handover .27
A.5 Conclusion.27
Annex E (informative): Document change history.28
History .29
ETSI
6 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
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://www.etsi.org/ipr).
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 European Standard (Telecommunications series) has been produced by ETSI Technical Committee Special Mobile
Group (SMG).
The present document was submitted to Public Enquiry with the ETSI number 301 404. For vote the number was
changed to 302 404 because the number 301 404 is reserved and was allocated accidentally.
The present document gives an overall description of the lower layers of the radio interface for GSM based Cordless
Telephony Systems.
The contents of the present document is subject to continuing work within SMG and may change following formal
SMG approval. Should SMG modify the contents of the present document it will be re-released with an identifying
change of release date and an increase in version number as follows:
Version 7.x.y
where:
7 indicates Release 1998 of GSM Phase 2+
x the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
y the third digit is incremented when editorial only changes have been incorporated in the specification.
National transposition dates
Date of adoption of this EN: 21 July 2000
Date of latest announcement of this EN (doa): 31 October 2000
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 April 2001
Date of withdrawal of any conflicting National Standard (dow): 30 April 2001
ETSI
7 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
1 Scope
The present document gives an overall description of the lower layers of the radio interface for GSM based Cordless
Telephony Systems (GSM-CTS).
The GSM-CTS system is intended to provide a cordless connection between the fixed network and GSM-based CTS
Mobile Stations (CTS-MS) via a private CTS Fixed Part (CTS-FP).
Stage 1 is an overall description, from the service subscribers and user’s standpoint, that view the network as a single
entity which provides service to the user. GSM 02.56 [2] contains the CTS Stage 1 service description.
GSM 03.56 [5] is a Stage 2 document that describes the system architecture of the GSM Cordless Telephone Systems
(GSM-CTS), i.e. the system elements, the system interfaces and the functional capabilities.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
• A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the
same number.
• For this Release 1998 document, references to GSM documents are for Release 1998 versions (version 7.x.y).
[1] GSM 01.04: "Digital cellular telecommunications system (Phase 2+); Abbreviations and
Acronyms".
[2] GSM 02.56: "Digital cellular telecommunications system (Phase 2+); GSM Cordless Telephone
System (CTS); Service Description; Stage 1".
[3] GSM 03.22: "Digital cellular telecommunications system (Phase 2+); Functions related to Mobile
Station (MS) in idle mode and group receive mode", Version 6.x.x.
[4] GSM 03.20: "Digital cellular telecommunications system (Phase 2+); GSM Cordless Telephone
System (CTS); Security related network functions; Stage 2".
[5] GSM 03.56: "Digital cellular telecommunications system (Phase 2+); GSM Cordless Telephony
System (CTS); CTS Architecture Description; Stage 2".
[6] GSM 04.08: "European digital cellular telecommunications system (Phase 2+); Mobile radio
interface layer 3 specification", Version 6.x.x.
[7] GSM 05.02: "Digital cellular telecommunications system (Phase 2+); Multiplexing and multiple
access on the radio path", Version 6.3.0.
[8] GSM 05.03: "Digital cellular telecommunications system (Phase 2+); Channel coding",
Version 6.1.0.
[9] GSM 05.04: "Digital cellular telecommunications system (Phase 2+); Modulation".
[10] GSM 05.05: "Digital cellular telecommunications system (Phase 2+); Radio transmission and
reception".
[11] GSM 05.08: "Digital cellular telecommunications system (Phase 2+); Radio subsystem link
control".
ETSI
8 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
[12] GSM 05.10: "Digital cellular telecommunications system (Phase 2+); Radio subsystem
synchronization".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
CTS Mobile Station: a GSM-MS supporting CTS.
CTS Fixed Part: the CTS-FP is a device which acts as a link between the CTS-MS and the fixed network
GSM-CTS: Cordless Telephony System based on GSM
3.2 Abbreviations
The following list describes the abbreviations and acronyms used in the present document. The GSM abbreviations
explained in GSM 01.04 [1] are not included below.
AFA Adaptive Frequency Allocation
CTS Cordless Telephony System
CTSAGCH CTS Access Grant CHannel
CTSARCH CTS Access Request CHannel
CTSBCH CTS Beacon CHannel
CTS-FP CTS Fixed Part
CTS-MS CTS Mobile Station
CTSMSI CTS Mobile Subscriber Identity
CTSPCH CTS Paging CHannel
DPLMN Donor Public Land Mobile Network
FPBI Fixed Part Beacon Identity
GFL Generic Frequency List
RX Receive
TFH Total Frequency Hopping
TX Transmit
4 Main concepts of the CTS radio interface
The main assumption behind the CTS work item and in particular the CTS radio interface, is that a modified single
timeslot state of the art GSM-MS chipset could be used for a home base station, i.e. as a CTS-FP.
The CTS radio interface has been designed to meet a requirement of low generated interference, either from the CTS to
existing overlaying PLMNS, either from a CTS to another CTS. This requirement is achieved by the combined usage of
the three concepts: beacon concept, AFA concept and TFH concept.
4.1 Beacon concept
A limited number of CTS-MS shall be served by one CTS-FP (see GSM 02.56 [2]). Therefore, a broadcast channel
continuously transmitted such as the BCCH in GSM is not needed for CTS.
A channel called CTS beacon channel (CTSBCH) is proposed with the following main characteristics: it is transmitted
by the CTS-FP every 26 frames in a 52-multiframe pattern, and allows the CTS-MS to synchronise with the CTS-FP.
Minimum signalling is also supported by the CTSBCH, so that it is the only logical channel a CTS-FP shall periodically
transmit on the CTS radio interface. Every other logical channel is only transmitted "on demand".
ETSI
9 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
4.2 Adaptive Frequency Allocation (AFA) concept
A precise radio frequency planning can not be applied to the CTS-FP/MS pair, as the CTS is intended to be deployed by
the end-user. Therefore, a list of frequencies (the GFL) on which it is allowed to operate is given to the CTS. With the
AFA, interference measurements will be performed on the frequencies in the GFL to provide a ranking in the AFA
table, in order to exclude unacceptably interfered frequencies from the usage in CTS.
4.3 Total Frequency Hopping (TFH) concept
The remaining frequencies are used by the Total Frequency Hopping algorithm in order to reduce the interference of the
CTS with the overlaying PLMN and other CTS-FP/MS pairs. With TFH the interference caused by the CTS link is
spread across multiple GSM links (interference averaging) and the co-channel interference is due to different users at
different locations (interference diversity).
A new hopping algorithm which is especially tailored for use in CTS with improved performance compared to the GSM
hopping algorithms shall be used.
5 Radio Transmission and Reception
The CTS-FP and CTS-MS shall in Phase 1 GSM-CTS conform to the transmission and reception specifications of at
least one or more of the following cellular standards:
- P-GSM900
- E-GSM900
- DCS1800
- PCS1900
The final choice of characteristics and performance requirements depends on system scenario calculations.
5.1 Frequency Band and Channel Arrangement
The frequency band and channel arrangement for the GSM-CTS are as specified in GSM 05.05 [10] clause 2.
5.2 Receiver Characteristics
5.2.1 CTS-MS characteristics
It is the intention to keep the CTS-MS characteristics in line with the GSM-MS characteristics as specified in
GSM 05.05 [10] clause 5, but the final decision depends on system scenario calculations.
5.2.2 CTS-FP characteristics
It is the intention to keep the CTS-FP characteristics in line with the GSM-MS characteristics as specified in
GSM 05.05 [10] clause 5, but with reversed frequency bands. The final decision depends on system scenario
calculations.
5.3 Transmitter Characteristics
5.3.1 CTS-MS characteristics
It is the intention to keep the CTS-MS characteristics as far as possible in line with the GSM-MS characteristics as
specified in GSM 05.05 [10] subclause 4, but the final decision depends on system scenario calculations.
ETSI
10 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
In addition, it is intended to lower the maximum nominal output power and the lowest nominal output power to values
which shall be determined by system scenario calculations. Both values could be below the nominal output powers
specified in GSM 05.05 [10] clause 4.1.1.
5.3.2 CTS-FP characteristics
It is the intention to keep the CTS-FP characteristics as far as possible in line with the GSM-MS characteristics as
specified in GSM 05.05 [10] subclause 4, but with reversed frequency bands. The final decision depends on system
scenario calculations.
In addition, it is intended to lower the maximum nominal output power and the lowest nominal output power to values
which shall be determined by system scenario calculations. Both values could be below the nominal output powers
specified in GSM 05.05 [10] subclause 4.1.1.
5.4 CTS transmitter / receiver performance
It is the intention to keep the CTS transmitter / receiver performance in line with the GSM transmitter / receiver
performance as specified in GSM 05.05 [10] clause 6.
The GSM requirement on receiver performance for frequency hopping where frequencies are interfered shall be
fulfilled by both the CTS-MS and CTS-FP.
6 Modulation and Raw Data Rates
The modulation technique and raw data rates are as specified in GSM 05.04 [9].
7 Channel Coding and Interleaving
The channel coding algorithm and interleaving schemes of existing GSM channels used in the GSM CTS radio interface
are as specified in GSM 05.03 [8].
Channel coding algorithms and interleaving schemes for new logical channels are defined in clause 10.
8 Time Slots and TDMA-Frames
The time slot organisation is as specified in GSM 05.02 [7] subclause 4.3.1.
The TDMA frames are organised in multiframes, superframes, and hyperframes. The hyperframe is the longest
recurrent time period and consists of 26 x 51 x 2048 TDMA frames. The TDMA frames are numbered modulo this
hyperframe, which means that the frame number FN ranges from 0 to FN_MAX= (26 x 51 x 2 ) -1 = 2715647. The
CTS-FP keeps track of the frame numbering once initialised.
Two types of multiframes exist in the GSM-CTS system:
• a 26-multiframe with a duration of 120 ms, comprising 26 TDMA frames. This multiframe is used to carry TCH,
SACCH, and FACCH (see clause 10).
• a 52-multiframe with a duration of 240 ms, comprising 52 TDMA frames. This multiframe is used to carry
CTSBCH, CTSARCH, CTSAGCH and CTSPCH (see clause 10), and is indicated as CTSBCH multiframe.
Note that GSM-CTS uses a scheme slightly different from the GSM-based frame structure in that instead of 51-
multiframes, 52-multiframes are used. The reason for this choice is that the bursts of the CTSBCH have a frame
distance that coincides with the idle frames of a TCH/F connection ; it is therefore possible to support in the CTS-FP a
speech connection and the CTSBCH transmission in parallel on the same timeslot, which allows the realisation of the
CTS-FP hardware with a state of the art chipset for a GSM-MS supporting only a single timeslot.
ETSI
11 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
9 Bursts
In the physical layer of the GSM-CTS system, three types of burst formats are used:
• Normal Burst (NB);
• Frequency Correction Burst (FB);
• Synchronisation Burst (SB).
They are as specified in GSM 05.02 [7] subclause 5.2, with the difference that the synchronisation bursts used in GSM-
CTS shall have a specific training sequence, in order to avoid misleading detection of a GSM-CTS synchronisation
bursts by a GSM-MS.
10 Logical Channels
For the GSM-CTS system, eight logical channels have been specified. There is one traffic channel TCH/F, and there are
six signalling channels CTSBCH, CTSARCH, CTSAGCH, CTSPCH, SACCH, and FACCH.
10.1 CTS Beacon Channel (CTSBCH)
The CTSBCH logical channel is used to provide frequency and synchronisation information in the downlink direction.
From this information the CTS-MS is able to synchronise and to recognise the identity of the CTS-FP. It is made up of a
pair of CTSBCH-SB and CTSBCH-FB transmitted in every 52-multiframe.
Signalling mechanisms have been defined in order to reduce emissions from both CTS-FP and CTS-MS.
In cases where the CTS-FP has no resources to handle accesses from a CTS-MS, the CTSBCH shall indicate that no
CTS-MS shall attempt to access the CTS-FP.
In order to avoid continuous broadcasting of the CTSPCH, signalling is provided on the CTSBCH that indicates the
presence of the CTSPCH.
10.1.1 CTSBCH format
• burst:
• Frequency Correction Burst (FB) is used for the CTSBCH-FB;
• Synchronisation Burst (SB) is used for the CTSBCH-SB.
• channel coding scheme:
• CTSBCH-SB uses the same channel coding scheme as the SCH, specified in GSM 05.03 [8] subclause 4.7.
No channel coding is required for CTSBCH-FB.
10.1.2 CTSBCH timing
The timing of the CTSBCH is as follows (see figure 1):
• frame position:
• FN mod 52 =25 the CTSBCH-FB is transmitted;
• FN mod 52 =51 the CTSBCH-SB is transmitted.
• timeslot position: a pair of CTSBCH-SB and CTSBCH-FB shall have the same timeslot position within one 52-
multiframe but the position can change from one 52-multiframe to another according to the Beacon timeslot
management procedure (see subclause 11.2).
ETSI
12 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
10.1.3 CTSBCH radio frequency channel
The CTSBCH is transmitted on the CTSBCH frequency channel, according to the CTSBCH frequency selection, see
subclause 12.2.2.
10.1.4 CTSBCH-SB information
The CTSBCH-SB carries 25 information bits. These 25 bits shall be divided into five fields as follows:
• a status field indicating whether the CTS-FP has any radio resource available;
• a flag indicating the presence of the CTSPCH in the next 52-multiframe;
• a flag indicating whether the CTS-FP is currently performing timeslot shifting (see 11.2) on the CTSBCH;
• a field indicating the timeslot number of the CTSARCH, CTSAGCH and CTSPCH;
• the FPBI field indicating the identity of the CTS-FP, in such a way that invalid attachment attempts by CTS-MS
which are not enrolled (see GSM 03.56 [5]) with this CTS-FP are minimised.
10.2 CTS Access Request Channel (CTSARCH)
The CTSARCH is transmitted in the uplink by the CTS-MS to request dedicated radio resources from the CTS-FP ; it is
also used during the Alive check procedure (see clause 12).
10.2.1 CTSARCH format
- burst: Synchrolisnisation Bursts (SB) are used for the CTSARCH.
NOTE: due to the short distance between the CTS-FP and the CTS-MS, there is no need to use a burst of reduced
length like the Access Burst (as specified in GSM 05.02 [7] subclause 5.2).
- channel coding scheme: same as for the SCH, specified in GSM 05.03 [8] subclause 4.7.
10.2.2 CTSARCH timing
The timing of the CTSARCH is as follows (see figure 1):
• frame position:
• FN mod 52 = 2 to 9 for CTSARCH used for the non-hopping access procedure, see subclause 12.3.3.2
FN mod 52 = 10 to 15 for CTSARCH used for the hopping access procedure (see subclause 12.3.3.2) and the alive
check procedure (see subclause 12.3.2) (see subclause 12.3.5).
• timeslot position: the CTSARCH is transmitted on a timeslot number which shall be indicated in the CTSBCH-
SB information bits (see 10.1.4).
10.2.3 CTSARCH radio frequency channel
The CTSARCH radio frequency channel is:
• the CTS beacon frequency for the CTSARCH used for the non-hopping access procedure, see subclause
12.3.3.2;
• mapped on a predefined set of frequencies by the Total Frequency Hopping for the CTSARCH used for the
hopping access procedure (see subclause 12.3.3.2) and the alive check procedure (see subclause 12.3.2.
Refer to subclause 10.8.2 for background on the choice of the radio frequency channel.
ETSI
13 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
10.2.4 CTSARCH information
The CTSARCH carries 25 information bits forming an access request message. These 25 bits shall be divided into two
fields as follows:
• a field indicating the cause of the type of the access request;
• a field carrying the CTS Mobile Subscriber Identity (CTSMSI) allocated to the CTS-MS.
10.3 CTS Access Grant Channel (CTSAGCH)
The CTSAGCH is used in the downlink by the CTS-FP to grant a dedicated RR connection to a CTS-MS that has
requested radio resources by the use of the CTSARCH.
10.3.1 CTSAGCH format
• burst: Normal Bursts (NB) are used for the CTSAGCH;
• training sequence: it is determined by the three LSBs of the FPBI. These three bits form the 3-bit training
sequence code (TSC) which selects one of the eight training sequences specified in GSM 05.02 [7]
subclause 5.2.3;
• channel coding and interleaving schemes: same as for the SACCH, as specified in GSM 05.03 [8] subclause 4.1,
over 4 consecutive bursts.
10.3.2 CTSAGCH timing
The timing of the CTSAGCH is as follows (see figure 1):
• frame position:
• FN mod 52 = 16 to 19 for the CTSAGCH used for the non-hopping access procedure, see subclause 12.3.3.2;
• FN mod 52 = 20 to 23 for the CTSAGCH used for the hopping access procedure, see subclause 12.3.3.2.
• timeslot position: the CTSAGCH is transmitted on a timeslot number which shall be indicated in the CTSBCH-
SB information bits (see 10.1.4).
10.3.3 CTSAGCH radio frequency channel
The CTSAGCH radio frequency channel is:
• the CTS beacon frequency for the CTSAGCH used for the non-hopping access procedure, see subclause
12.3.3.2;
• mapped on a predefined set of frequencies by the Total Frequency Hopping for the CTSAGCH used for the
hopping access procedure, see subclause 12.3.3.2.
Refer to subclause 10.8.2 for background on the choice of the radio frequency channel.
10.3.4 CTSAGCH information
The CTSAGCH carries 23 octets of information, forming a message which directs the CTS-MS to a channel on which
the RR connection can be continued. This message provides the CTS-MS with channel and timing information.
ETSI
14 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
10.4 CTS Paging Channel (CTSPCH)
The CTSPCH is used in the downlink by the CTS-FP to broadcast information for paging (see subclause 12.3.3.3) and
alive check (see subclause 12.3.2) procedures. The presence of the CTSPCH on the physical channel is indicated by a
signalling information in the CTSBCH (see subclause 10.1.4).
10.4.1 CTSPCH format
• burst: Normal Bursts (NB) are used for the CTSPCH;
• training sequence: it is determined by the three LSBs of the FPBI. These three bits form the 3-bit training
sequence code (TSC) which selects one of the eight training sequences specified in GSM 05.02 [7] subclause
5.2.3;
• channel coding and interleaving schemes: same as for the SACCH, as specified in GSM 05.03 [8] subclause 4.1,
over 4 consecutive bursts.
10.4.2 CTSPCH timing
The timing of the CTSPCH is as follows (see figure 1):
• frame position: FN mod 52 = 2 to 5;
• timeslot position: the CTSPCH is transmitted on a timeslot number which shall be indicated in the CTSBCH-SB
information bits (see 10.1.4).
10.4.3 CTSPCH radio frequency channel
The CTSPCH radio frequency channel is mapped on a predefined set of frequencies by the Total Frequency Hopping
algorithm.
Refer to subclause 10.8.2 for background on the choice of the radio frequency channel.
10.4.4 CTSPCH information
The CTSPCH contains 23 octets of information, forming the following possible messages:
• a message used for the paging procedure, see subclause 12.3.3.3;
• a message used for alive check procedure, see subclause 12.3.2.
10.5 SACCH
In GSM-CTS, the TDMA frames where the CTSBCH is transmitted (FN mod 26 = 25) are not available for any
SACCH transmission, in contrary to GSM. This results in the requirement that the SACCH multiframe shall span 104
TDMA frames (480 ms) as for GSM, however the interleaving scheme of the 4 SACCH bursts shall be so that no
SACCH burst is sent in the TDMA frames: FN mod 104 = 25, 51, 77 or 103.
Therefore, the mapping in time of the 4 SACCH/CTS frames onto the physical channel shall be as follows:
TN = 0 and 1 FN mod 104 = 12, 38, 64, 90
TN = 2 and 3 FN mod 104 = 38, 64, 90, 12
TN = 4 and 5 FN mod 104 = 64, 90, 12, 38
TN = 6 and 7 FN mod 104 = 90, 12, 38, 64.
The timing of the SACCH on the 26-multiframe is shown on figure 2.
ETSI
15 ETSI EN 302 404 V7.1.1 (2000-08)
(GSM 03.52 version 7.1.1 Release 1998)
The SACCH radio frequency channel is mapped on a predefined set of frequencies by the Total Frequency Hopping
algorithm, as defined in subclause 10.8.2, except in the case of the non-hopping access procedure (for the attachment or
enrolment of a CTS-MS), where the SACCH is mapped on the CTS beacon frequency.
SACCH is a point-to-point dedicated control channel used to transmit signalling messages for the layered GSM-CTS
protocol.
10.6 FACCH
The standard GSM FACCH as defined in GSM 05.02 [7] is used in GSM-CTS. Full rate FACCH/F is supported.
The timing of the FACCH on the 26-multiframe is shown on figure 2.
The FACCH radio frequency channel is mapped on a predefined set of frequencies by the Total Frequency Hopping
algorithm, as defined in subclause 10.8.2, except in the case of the non-hopping access procedure (for the attachment or
enrolment of a CTS-MS), where the FACCH is mapped on the CTS beacon frequency.
FACCH is a point-to-point dedicated control channel used to transmit signalling messages for the GSM-CTS layered
protocol.
10.7 TCH
The traffic channel TCH used in GSM-CTS is the st
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...