SIST ETS 300 908 E1:2003
(Main)Digital cellular telecommunications system (Phase 2+) (GSM); Multiplexing and multiple access on the radio path (GSM 05.02 version 5.2.1)
Digital cellular telecommunications system (Phase 2+) (GSM); Multiplexing and multiple access on the radio path (GSM 05.02 version 5.2.1)
This European Telecommunication Standard (ETS) defines the physical channels of the radio sub-system required to support the logical channels. It includes a description of the logical channels and the definition of frequency hopping, TDMA frames, timeslots and bursts.
Digitalni celični telekomunikacijski sistem (faza 2+) – Multipleksiranje in sodostop na radijski poti (GSM 05.02, različica 5.2.1)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2003
'LJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHP ID]D ±0XOWLSOHNVLUDQMHLQVRGRVWRS
QDUDGLMVNLSRWL *60UD]OLþLFD
Digital cellular telecommunications system (Phase 2+) (GSM); Multiplexing and multiple
access on the radio path (GSM 05.02 version 5.2.1)
Ta slovenski standard je istoveten z: ETS 300 908 Edition 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 ETS 300 908
TELECOMMUNICATION April 1997
STANDARD
Source: ETSI TC-SMG Reference: DE/SMG-020502QR1
ICS: 33.020
Key words: Digital cellular telecommunications system, Global System for Mobile communications (GSM)
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
Digital cellular telecommunications system (Phase 2+);
Multiplexing and multiple access on the radio path
(GSM 05.02 version 5.2.1)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 4 92 94 42 00 - Fax: +33 4 93 65 47 16
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 1997. All rights reserved.
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ETS 300 908 (GSM 05.02 version 5.2.1): April 1997
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.
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ETS 300 908 (GSM 05.02 version 5.2.1): April 1997
Contents
Foreword .5
1 Scope .7
1.1 Normative references .7
1.2 Abbreviations .7
2 General.7
3 Logical channels.8
3.1 General .8
3.2 Traffic channels .8
3.2.1 General.8
3.2.2 Speech traffic channels.8
3.2.3 Data traffic channels.8
3.3 Control channels.8
3.3.1 General.8
3.3.2 Broadcast channels.9
3.3.2.1 Frequency correction channel (FCCH).9
3.3.2.2 Synchronization channel (SCH).9
3.3.2.3 Broadcast control channel (BCCH) .9
3.3.3 Common control type channels, known when combined as a common
control channel (CCCH) .10
3.3.4 Dedicated control channels.10
3.3.5 Cell Broadcast Channel (CBCH).10
3.4 Combination of channels .10
4 The physical resource .10
4.1 General .10
4.2 Radio frequency channels .10
4.2.1 Cell allocation and mobile allocation .10
4.2.2 Downlink and uplink .11
4.3 Timeslots and TDMA frames.11
4.3.1 General.11
4.3.2 Timeslot number .11
4.3.3 TDMA frame number.11
5 Physical channels.11
5.1 General .11
5.2 Bursts.12
5.2.1 General.12
5.2.2 Types of burst and burst timing.12
5.2.3 Normal burst (NB) .12
5.2.4 Frequency correction burst (FB).13
5.2.5 Synchronization burst (SB).13
5.2.6 Dummy burst.13
5.2.7 Access burst (AB).14
5.2.8 Guard period .14
5.3 Physical channels and bursts .14
5.4 Radio frequency channel sequence.15
5.5 Timeslot and TDMA frame sequence.15
5.6 Parameters for channel definition and assignment .15
5.6.1 General.15
5.6.2 General parameters .15
5.6.3 Specific parameters .15
6 Mapping of logical channels onto physical channels.16
6.1 General .16
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6.2 Mapping in frequency of logical channels onto physical channels . 16
6.2.1 General . 16
6.2.2 Parameters . 16
6.2.3 Hopping sequence generation. 16
6.2.4 Specific cases. 18
6.2.5 Change in the frequency allocation of a base transceiver station . 18
6.3 Mapping in time of logical channels onto physical channels. 18
6.3.1 General . 18
6.3.2 Key to the mapping table of clause 7. 18
6.3.3 Mapping of TCH/F9.6, TCH/F4.8, TCH/H4.8 and TCH/H2.4 . 19
6.3.4 Mapping of BCCH data. 19
6.3.5 Mapping of SID Frames. 19
6.4 Permitted channel combinations. 19
6.4.1 Permitted channel combinations onto a basic physical channel. 20
6.4.2 Multislot configurations . 20
6.5 Operation of channels and channel combinations . 21
6.5.1 General . 21
6.5.2 Determination of CCCH_GROUP and PAGING_GROUP . 22
6.5.3 Determination of specific paging multiframe and paging block index. 22
6.5.4 Short Message Service Cell Broadcast (SMSCB). 22
6.5.5 Voice group and voice broadcast call notifications. 23
Annex A (normative): Phase 2 mobiles in a phase 1 infrastructure. 37
A.1 Scope. 37
A.2 Implementation options for TCH channels . 37
A.2.1 C0 filling on the TCH . 37
A.2.1.1 A dummy burst with (BN61,BN62, BN86) = training sequence bits of
normal bursts. 37
A.2.1.2 A dummy burst with the "C0 filling training sequence. 37
A.2.1.3 A dummy burst with (BN61, BN62, BN86) mapped from the TSC bits of
normal bursts according to the table below . 37
A.2.1.4 Partial SID information. 37
A.2.2 Half burst filling. 37
A.2.2.1 Partial SID information from any associated SID frame; or. 37
A.2.2.2 The mixed bits of the dummy bursts (encrypted or not encrypted) . 37
A.2.3 Dummy burst Stealing flag . 37
A.2.4 Half burst Filling Stealing flag. 37
A.2.5 Allowed combinations. 38
A.3 Idle Channels. 38
Annex B (normative): Multislot capability. 39
B.1 MS classes for multislot capability. 39
B.2 Constraints imposed by the service selected . 40
B.3 Network requirements for supporting MS multislot classes. 40
History. 43
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ETS 300 908 (GSM 05.02 version 5.2.1): April 1997
Foreword
This European Telecommunication Standard (ETS) has been produced by the Special Mobile Group
(SMG) Technical Committee (TC) of the European Telecommunications Standards Institute (ETSI).
This ETS defines the physical channels of the radio sub-system required to support the logical channels of
the digital mobile cellular and personal communication systems operating in the 900 MHz and 1 800 MHz
band (GSM 900 and DCS 1 800).
This ETS is a GSM technical specification version 5, which incorporates GSM Phase 2+
enhancements/features to the version 4 GSM technical specification. The ETS from which this Phase 2+
ETS has evolved is Phase 2 GSM ETS 300 574 Edition 5 (GSM 05.02 version 4.8.1).
The contents of this ETS is subject to continuing work within TC-SMG and may change following formal
TC-SMG approval. Should TC-SMG modify the contents of this ETS, it will be resubmitted for OAP by
ETSI with an identifying change of release date and an increase in version number as follows:
Version 5.x.y
where:
y the third digit is incremented when editorial only changes have been incorporated in the
specification;
x the second digit is incremented for all other types of changes, i.e. technical enhancements,
corrections, updates, etc.
The specification from which this ETS has been derived was originally based on CEPT documentation,
hence the presentation of this ETS may not be entirely in accordance with the ETSI drafting rules.
Transposition dates
Date of adoption: 21 March 1997
Date of latest announcement of this ETS (doa): 31 July 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 January 1998
Date of withdrawal of any conflicting National Standard (dow): 31 January 1998
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1 Scope
This European Telecommunication Standard (ETS) defines the physical channels of the radio sub-system
required to support the logical channels. It includes a description of the logical channels and the definition
of frequency hopping, TDMA frames, timeslots and bursts.
1.1 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references, the
latest edition of the publication referred to applies.
[1] GSM 01.04 (ETR 350): "Digital cellular telecommunications system (Phase 2+);
Abbreviations and acronyms".
[2] GSM 03.03 (ETS 300 927): "Digital cellular telecommunications system
(Phase 2+); Numbering, addressing and identification".
[3] GSM 04.03: "Digital cellular telecommunications system (Phase 2+); Mobile
Station - Base Station System (MS - BSS) interface Channel structures and
access capabilities".
[4] GSM 04.06 (ETS 300 938): "Digital cellular telecommunications system
(Phase 2+); Mobile Station - Base Station System (MS - BSS) interface; Data
Link (DL) layer specification".
[5] GSM 04.08 (ETS 300 940): "Digital cellular telecommunications system
(Phase 2+); Mobile radio interface layer 3 specification".
[6] GSM 05.03 (ETS 300 909): "Digital cellular telecommunications system
(Phase 2+); Channel coding".
[7] GSM 05.04 (ETS 300 959): "Digital cellular telecommunications system;
Modulation".
[8] GSM 05.05 (ETS 300 910): "Digital cellular telecommunications system
(Phase 2+); Radio transmission and reception".
[9] GSM 05.08 (ETS 300 911): "Digital cellular telecommunications system
(Phase 2+); Radio subsystem link control".
[10] GSM 05.10 (ETS 300 912): "Digital cellular telecommunications system
(Phase 2+); Radio subsystem synchronization".
1.2 Abbreviations
Abbreviations used in this ETS are listed in GSM 01.04 [1].
2 General
The radio subsystem is required to support a certain number of logical channels that can be separated
into two overall categories as defined in GSM 04.03:
i) The traffic channels (TCH's).
ii) The control channels.
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More information is given about these logical channels in clause 3 which also defines a number of special
channels used by the radio sub-system.
Clause 4 of this document describes the physical resource available to the radio sub-system, clause 5
defines physical channels based on that resource and clause 6 specifies how the logical channels shall be
mapped onto physical channels. Figure 1 depicts this process.
3 Logical channels
3.1 General
This clause describes the logical channels that are supported by the radio subsystem.
3.2 Traffic channels
3.2.1 General
Traffic channels (TCH's) are intended to carry either encoded speech or user data. Two general forms of
traffic channel are defined:
i) Full rate traffic channel (TCH/F). This channel carries information at a gross rate of
22,8 kbit/s.
ii) Half rate traffic channel (TCH/H). This channel carries information at a gross rate of
11,4 kbit/s.
All traffic channels are bi-directional unless otherwise stated. Unidirectional downlink full rate channels,
TCH/FD, are defined as the downlink part of the corresponding TCH/F.
Multiple full rate channels can be allocated to the same MS. This is referred to as multislot configurations,
which is defined in subclause 6.4.2.
The specific traffic channels available in the categories of speech and user data are defined in the clauses
following.
3.2.2 Speech traffic channels
The following traffic channels are defined to carry encoded speech:
i) Full rate traffic channel for speech (TCH/FS).
ii) Half rate traffic channel for speech (TCH/HS).
3.2.3 Data traffic channels
The following traffic channels are defined to carry user data:
i) Full rate traffic channel for 9,6 kbit/s user data (TCH/F9.6).
ii) Full rate traffic channel for 4,8 kbit/s user data (TCH/F4.8).
iii) Half rate traffic channel for 4,8 kbit/s user data (TCH/H4.8).
iv) Half rate traffic channel for ≤ 2,4 kbit/s user data (TCH/H2.4).
v) Full rate traffic channel for ≤ 2,4 kbit/s user data (TCH/F2.4).
3.3 Control channels
3.3.1 General
Control channels are intended to carry signalling or synchronization data. Three categories of control
channel are defined: broadcast, common and dedicated. Specific channels within these categories are
defined in the clauses following.
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3.3.2 Broadcast channels
3.3.2.1 Frequency correction channel (FCCH)
The frequency correction channel carries information for frequency correction of the mobile station. It is
required only for the operation of the radio sub-system.
3.3.2.2 Synchronization channel (SCH)
The synchronization channel carries information for frame synchronization of the mobile station and
identification of a base transceiver station. It is required only for the operation of the radio sub-system.
Specifically the synchronization channel shall contain two encoded parameters:
a) Base transceiver station identity code (BSIC): 6 bits (before channel coding) consists of 3 bits
of PLMN colour code with range 0 to 7 and 3 bits of BS colour code with range 0 to 7 as
defined in GSM 03.03.
b) Reduced TDMA frame number (RFN): 19 bits (before channel coding) =
T1 (11 bits) range 0 to 2047 = FN div (26 x 51)
T2 (5 bits) range 0 to 25 = FN mod 26
T3' (3 bits) range 0 to 4 = (T3 - 1) div 10
where:
T3 (6 bits) range 0 to 50 = FN mod 51
and
FN = TDMA frame number as defined in subclause 4.3.3.
GSM 04.06 and GSM 04.08 specify the precise bit ordering, GSM 05.03 the channel coding of the above
parameters and GSM 05.10 defines how the TDMA frame number can be calculated from T1, T2, and
T3'.
3.3.2.3 Broadcast control channel (BCCH)
The broadcast control channel broadcasts general information on a base transceiver station per base
transceiver station basis. Of the many parameters contained in the BCCH, the use of the following
parameters, as defined in GSM 04.08 are referred to in subclause 6.5:
a) CCCH_CONF which indicates the organization of the common control channels:
From this parameter, the number of common control channels (BS_CC_CHANS) and
whether or not CCCH or SDCCH are combined (BS_CCCH_SDCCH_COMB = true or false)
are derived as follows:
CCCH_CONF BS_CC_CHANS BS_CCCH_SDCCH_COMB
000 1 false
001 1 true
010 2 false
100 3 false
110 4 false
b) BS_AG_BLKS_RES which indicates the number of blocks on each common control channel
reserved for access grant messages:
3 bits (before channel coding) range 0 to 7.
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c) BS_PA_MFRMS which indicates the number of 51 TDMA frame multiframes between
transmission of paging messages to mobiles of the same paging group:
3 bits (before channel coding) range 2 to 9.
3.3.3 Common control type channels, known when combined as a common control channel
(CCCH)
i) Paging channel (PCH): Downlink only, used to page mobiles.
ii) Random access channel (RACH): Uplink only, used to request allocation of a SDCCH.
iii) Access grant channel (AGCH): Downlink only, used to allocate a SDCCH or directly a TCH.
iv) Notification channel (NCH): Downlink only, used to notify mobile stations of voice group and
voice broadcast calls.
3.3.4 Dedicated control channels
i) Slow, TCH/F associated, control channel (SACCH/TF).
ii) Fast, TCH/F associated, control channel (FACCH/F).
iii) Slow, TCH/H associated, control channel (SACCH/TH).
iv) Fast, TCH/H associated, control channel (FACCH/H).
v) Stand alone dedicated control channel (SDCCH/8).
vi) Slow, SDCCH/8 associated, control channel (SACCH/C8).
vii) Stand alone dedicated control channel, combined with CCCH (SDCCH/4).
viii) Slow, SDCCH/4 associated, control channel (SACCH/C4).
ix) slow, TCH/F associated, control channel for multislot configurations (SACCH/M).
All associated control channels have the same direction (bi-directional or unidirectional) as the
channels they are associated to. The unidirectional SACCH/MD is defined as the downlink part of
SACCH/M.
3.3.5 Cell Broadcast Channel (CBCH)
The CBCH, downlink only, is used to carry the short message service cell broadcast (SMSCB). The
CBCH uses the same physical channel as the SDCCH.
3.4 Combination of channels
Only certain combinations of channels are allowed as defined in GSM 04.03. Subclause 6.4 lists the
combinations in relation to basic physical channels.
4 The physical resource
4.1 General
The physical resource available to the radio sub-system is an allocation of part of the radio spectrum. This
resource is partitioned both in frequency and time. Frequency is partitioned by radio frequency channels
(RFCHs) divided into bands as defined in GSM 05.05. Time is partitioned by timeslots and TDMA frames
as defined in subclause 4.3 of this ETS.
4.2 Radio frequency channels
4.2.1 Cell allocation and mobile allocation
GSM 05.05 defines radio frequency channels (RFCHs), and allocates numbers to all the radio frequency
channels available to the system. Each cell is allocated a subset of these channels, defined as the cell
allocation (CA). One radio frequency channel of the cell allocation shall be used to carry synchronization
information and the BCCH, this shall be known as BCCH carrier. The subset of the cell allocation,
allocated to a particular mobile, shall be known as the mobile allocation (MA).
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4.2.2 Downlink and uplink
The downlink comprises radio frequency channels used in the base transceiver station to mobile station
direction.
The uplink comprises radio frequency channels used in the mobile station to base transceiver station
direction.
4.3 Timeslots and TDMA frames
4.3.1 General
A timeslot shall have a duration of 3/5 200 seconds (≈ 577 μs). Eight timeslots shall form a TDMA frame
(≈ 4,62 ms in duration).
At the base transceiver station the TDMA frames on all of the radio frequency channels in the downlink
shall be aligned. The same shall apply to the uplink (see GSM 05.10).
At the base transceiver station the start of a TDMA frame on the uplink is delayed by the fixed period of
3 timeslots from the start of the TDMA frame on the downlink (see figure 2).
At the mobile station this delay will be variable to allow adjustment for signal propagation delay. The
process of adjusting this advance is known as adaptive frame alignment and is detailed in GSM 05.10.
The staggering of TDMA frames used in the downlink and uplink is in order to allow the same timeslot
number to be used in the downlink and uplink whilst avoiding the requirement for the mobile station to
transmit and receive simultaneously. The period includes time for adaptive frame alignment, transceiver
tuning and receive/transmit switching (see figure 4).
4.3.2 Timeslot number
The timeslots within a TDMA frame shall be numbered from 0 to 7 and a particular timeslot shall be
referred to by its timeslot number (TN).
4.3.3 TDMA frame number
TDMA frames shall be numbered by a frame number (FN). The frame number shall be cyclic and shall
have a range of 0 to FN_MAX where FN_MAX = (26 x 51 x 2048) -1 = 2715647 as defined in GSM 05.10.
The frame number shall be incremented at the end of each TDMA frame.
The complete cycle of TDMA frame numbers from 0 to FN_MAX is defined as a hyperframe. A
hyperframe consists of 2 048 superframes where a superframe is defined as 26 x 51 TDMA frames. A
26 TDMA frame multiframe is used to support traffic and associated control channels and a 51 TDMA
frame multiframe is used to support broadcast, common control and stand alone dedicated control (and
their associated control) channels. Hence a superframe may be considered as 51 traffic/associated
control multiframes or 26 broadcast/common control multiframes.
The need for a hyperframe of a substantially longer period than a superframe arises from the
requirements of the encryption process which uses FN as an input parameter.
5 Physical channels
5.1 General
A physical channel uses a combination of frequency and time division multiplexing and is defined as a
sequence of radio frequency channels and time slots. The complete definition of a particular physical
channel consists of a description in the frequency domain, and a description in the time domain.
The description in the frequency domain is addressed in subclause 5.4, the description in the time domain
is addressed in subclause 5.5.
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5.2 Bursts
5.2.1 General
A burst is a period of R.F. carrier which is modulated by a data stream. A burst therefore represents the
physical content of a timeslot.
5.2.2 Types of burst and burst timing
A timeslot is divided into 156,25 bit periods. A particular bit period within a timeslot is referenced by a bit
number (BN), with the first bit period being numbered 0, and the last (1/4) bit period being numbered 156.
In the clauses following the transmission timing of a burst within a timeslot is defined in terms of bit
number. The bit with the lowest bit number is transmitted first.
Different types of burst exist in the system. One characteristic of a burst is its useful duration. This
document, in the clauses following, defines four full bursts of 147 bits useful duration, and one short burst
of 87 bits useful duration. The useful part of a burst is defined as beginning from half way through bit
number 0. The definition of the useful part of a burst needs to be considered in conjunction with the
requirements placed on the phase and amplitude characteristics of a burst as specified in GSM 05.04 and
05.05.
The period between bursts appearing in successive timeslots is termed the guard period. Subclause 5.2.8
details constraints which relate to the guard period.
5.2.3 Normal burst (NB)
Bit Number Length Contents Definition
(BN) of field of field
0 - 2 3 tail bits (below)
3 - 60 58 encrypted bits (e0 . e57) 05.03
61 - 86 26 training sequence bits (below)
87 - 144 58 encrypted bits (e58 . e115) 05.03
145 - 147 3 tail bits (below)
(148 - 156 8,25 guard period (bits) (subclause 5.2.8)
- where the "tail bits" are defined as modulating bits with states as follows:
(BN0, BN1, BN2) = (0, 0, 0); and
(BN145, BN146, BN147) = (0, 0, 0);
- where the "training sequence bits" are defined as modulating bits with states as given in the
following table according to the training sequence code, TSC. For broadcast and common control
channels, the TSC must be equal to the BCC, as defined in GSM 03.03 and as described in this
ETS in subclause 3.3.2.
Training Training sequence bits
Sequence (BN61, BN62 . BN86)
Code (TSC)
(0,0,1,0,0,1,0,1,1,1,0,0,0,0,1,0,0,0,1,0,0,1,0,1,1,1)
(0,0,1,0,1,1,0,1,1,1,0,1,1,1,1,0,0,0,1,0,1,1,0,1,1,1)
(0,1,0,0,0,0,1,1,1,0,1,1,1,0,1,0,0,1,0,0,0,0,1,1,1,0)
(0,1,0,0,0,1,1,1,1,0,1,1,0,1,0,0,0,1,0,0,0,1,1,1,1,0)
(0,0,0,1,1,0,1,0,1,1,1,0,0,1,0,0,0,0,0,1,1,0,1,0,1,1)
(0,1,0,0,1,1,1,0,1,0,1,1,0,0,0,0,0,1,0,0,1,1,1,0,1,0)
(1,0,1,0,0,1,1,1,1,1,0,1,1,0,0,0,1,0,1,0,0,1,1,1,1,1)
(1,1,1,0,1,1,1,1,0,0,0,1,0,0,1,0,1,1,1,0,1,1,1,1,0,0)
Under certain circumstances only half the encrypted bits present in a normal burst will contain complete
information. For downlink DTX operation on TCH-FS and TCH-HS, when a traffic frame (as defined in
GSM 06.31) is scheduled for transmission and one of its adjacent traffic frames is not scheduled for
transmission, the other half of the encrypted bits in the normal bursts associated with the scheduled traffic
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frame shall contain partial SID information from any associated SID frame, with the appropriate stealing
flags BN60 or BN87 set to 0. In other cases the binary state of the remaining bits is not specified.
5.2.4 Frequency correction burst (FB)
length Contents Definition
Bit Number
of field of field
(BN)
- 2 3 tail bits (below)
- 144 142 fixed bits (below)
- 147 3 tail bits (below)
- 156 8,25 guard period (bits) (subclause 5.2.8)
(148
- where the "tail bits" are defined as modulating bits with states as follows:
(BN0, BN1, BN2) = (0, 0, 0); and
(BN145, BN146, BN147) = (0, 0, 0);
- where the "fixed bits" are defined as modulating bits with states as follows:
(BN3, BN4 . BN144) = (0, 0 . 0).
NOTE: This burst is equivalent to unmodulated carrier with a +1 625/24 kHz frequency offset,
above the nominal carrier frequency.
5.2.5 Synchronization burst (SB)
Length Contents Definition
Bit Number
of field of field
(BN)
0 - 2 3 tail bits (below)
3 - 41 39 encrypted bits (e0 . e38) 05.03
42 - 105 64 extended training sequence bits (below)
106 - 144 39 encrypted bits (e39 . e77) 05.03
145 - 147 3 tail bits (below)
(148 - 156 8,25 guard period (bits) (subclause 5.2.8)
- where the "tail bits" are defined as modulating bits with states as follows:
(BN0, BN1, BN2) = (0, 0, 0); and
(BN145, BN146, BN147) = (0, 0, 0);
- where the "extended training sequence bits" are defined as modulating bits with states as follows:
(BN42, BN43 . BN105) = (1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0,
0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0,
1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1)
5.2.6 Dummy burst
Length Contents Definition
Bit Number
of field of field
(BN)
- 2 tail bits (below)
0 3
- 144 mixed bits (below)
3 142
- 147 tail bits (below)
145 3
- 156 guard period (bits) (subclause 5.2.8)
(148 8,25
- where the "tail bits" are defined as modulating bits with states as follows:
(BN0, BN1, BN2) = (0, 0, 0); and
(BN145, BN146, BN147) = (0, 0, 0);
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- where the "mixed bits" are defined as modulating bits with states as follows:
(BN3, BN4 . BN144) = (1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1,
0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0,
0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0,
0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1
0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0,
1, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 0,
1, 0, 1, 0)
5.2.7 Access burst (AB)
Length Contents Definition
Bit Number
of field of field
(BN)
- 7 8 extended tail bits (below)
- 48 41 synch. sequence bits (below)
- 84 36 encrypted bits (e0.e35) 05.03
- 87 3 tail bits (below)
- 156 68,25 extended guard period (bits) (subclause 5.2.8)
(88
- where the "extended tail bits" are defined as modulating bits with the following states:
(BN0, BN1, BN2 . BN7) = (0, 0, 1, 1, 1, 0, 1, 0);
- where the "tail bits" are defined as modulating bits with the following states:
(BN85, BN86, BN87) = (0, 0, 0);
- where the "sync. sequence bits" are defined as modulating bits with the following states:
(BN8, BN9 . BN48) = (0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0,
1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0).
5.2.8 Guard period
The guard period is provided because it is required for the MSs that transmission be attenuated for the
period between bursts with the necessary ramp up and down occurring during the guard periods as
defined in GSM 05.05. A base transceiver station is not required to have a capability to ramp down and up
between adjacent bursts, but is required to have a capability to ramp down and up for non-used time-slots,
as defined in GSM 05.05. In any case where the amplitude of transmission is ramped up and down, then
by applying an appropriate modulation bit stream interference to other RF channels can be minimized.
5.3 Physical channels and bursts
The description of a physical channel will be made in terms of timeslots and TDMA frames and not in
terms of bursts. This is because there is not a one to one mapping between a particular physical channel,
and the use of a particular burst.
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5.4 Radio frequency channel sequence
The radio frequency channel sequence is determined by a function that, in a given cell, with a given set of
general parameters, (see subclause 5.6.2), with a given timeslot number (TN), a given mobile radio
frequency channel allocation (MA) and a given mobile allocation index offset (MAIO), maps the TDMA
frame number (FN) to a radio frequency channel.
In a given cell there is therefore, for a physical channel assigned to a particular mobile, a unique
correspondence between radio frequency channel and TDMA frame number.
The detailed hopping generation algorithm is given in subclause 6.2
5.5 Timeslot and TDMA frame sequence
A given physical channel shall always use the same timeslot number in every TDMA frame. Therefore a
timeslot sequence is defined by:
i) a timeslot number (TN); and
ii) a TDMA frame number sequence.
The detailed definitions of TDMA frame number sequences are given in clause 7.
The physical channels where the TDMA frame number sequence is 0,1. . FN_MAX (where FN_MAX is
defined in subclause 4.3.3) are called "basic physical channels".
5.6 Parameters for channel definition and assignment
5.6.1 General
This clause describes the set of parameters necessary to describe fully the mapping of any logical
channel onto a physical channel. These parameters may be divided into general parameters, that are
characteristic of a particular base transceiver station, and specific parameters, that are characteristic of a
given physical channel.
5.6.2 General parameters
These are:
i) the set of radio frequency channels used in the cell (CA), together with the identification of
the BCCH carrier;
ii) the TDMA frame number (FN), which can be derived from the reduced TDMA frame number
(RFN) which is in the form T1, T2, T3', see subclause 3.3.2.
These parameters are broadcast (or derived from parameters broadcast) in the BCCH and SCH.
5.6.3 Specific parameters
These parameters define a particular physical channel in a base transceiver station. They are:
o) the training sequence Code (TSC);
i) the timeslot number (TN);
ii) the mobile radio frequency channel allocation (MA);
iii) the mobile allocation index offset (MAIO);
iv) the hopping sequence number (HSN);
v) the type of logical channel;
vi) the sub-channel number (SCN).
The last two parameters allow the determination of the frame sequence.
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6 Mapping of logical channels onto physical channels
6.1 General
The detailed mapping of logical channels onto physical channels is defined in the following clauses.
Subclause 6.2 defines the mapping from TDMA frame number (FN) to radio frequency channel (RFCH).
Subclause 6.3 defines the mapping of the physical channel onto TDMA frame number. Subclause 6.4 lists
the permitted channel combinations and subclause 6.5 defines the operation of channels and channel
combinations.
6.2 Mapping in frequency of logical channels onto physical channels
6.2.1 General
The parameters used in the function which maps TDMA frame number onto radio frequency channel are
defined in subclause 6.2.2. The definition of the actual mapping function, or as it is termed, hopping
sequence generation is given in subclause 6.2.3.
6.2.2 Parameters
The following parameters are required in the mapping from TDMA frame number to radio frequency
channel for a given assigned channel.
General parameters of the BTS, specific to one BTS, and broadcast in the BCCH and SCH:
i) CA: Cell allocation of radio frequency channels.
ii) FN: TDMA frame number, broadcast in the SCH, in form T1, T2, T3' (see subclause 3.3.2).
Specific parameters of the channel, defined in the channel assignment message:
i) MA: Mobile allocation of radio frequency channels, defines the set of radio frequency
channels to be used in the mobiles hopping sequence. The MA contains N radio frequency
channels, where 1 ≤ N ≤ 64.
ii) MAIO: Mobile allocation index offset.(0 to N-1, 6 bits).
iii) HSN: Hopping sequence (generator) number (0 to 63, 6 bits).
6.2.3 Hopping sequence generation
For a given set of parameters, the index to an absolute radio frequency channel number (ARFCN) within
the mobile allocation (MAI from 0 to N-1, where MAI=0 represents the lowest absolute radio frequency
channel number (ARFCN) in the mobile allocation, ARFCN is in the range 0 to 7023 and the frequency
value can be determined according to GSM 05.05 sec 2 with n= ARFCN), is obtained with the following
algorithm:
if HSN = 0 (cyclic hopping) then:
MAI, integer (0 . N-1) : MAI = (FN + MAIO) modulo N;
else:
M, integer (0 . 152) : M = T2 + RNTABLE((HSN xor T1R) + T3);
S, integer (0 . N-1) : M' = M modulo (2 ^ NBIN);
T' = T3 modulo (2 ^ NBIN);
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if M' < N then:
S = M';
else:
S = (M'+T') modulo N;
MAI, integer (0 . N-1) : MAI = (S + MAIO) modulo N;
NOTE: Due to the procedure used by the mobile for measurement reporting when DTX is
used, the use of cyclic hopping where (N)mod 13 = 0 should be avoided.
where:
T1R: time parameter T1, reduced modulo 64 (6 bits).
T3: time parameter, from 0 to 50 (6 bits).
T2: time parameter, from 0 to 25 (5 bits).
NBIN: number of bits required to represent N = INTEGER(log (N)+1).
^: raised to the power of.
xor: bit-wise exclusive or of 8 bit binary operands.
RNTABLE: Table of 114 integer numbers, defined below:
Address Contents
000.009: 48, 98, 63, 1, 36, 95, 78, 102, 94, 73,
010.019: 0, 64, 25, 81, 76, 59, 124, 23, 104, 100,
020.029: 101, 47, 118, 85, 18, 56, 96, 86, 54, 2,
030.039: 80, 34, 127, 13, 6, 89, 57, 103, 12, 74,
040.049: 55, 111, 75, 38, 109, 71, 112, 29, 11, 88,
050.059: 87, 19, 3, 68, 110, 26, 33, 31, 8, 45,
060.069: 82, 58, 40, 107, 32, 5, 106, 92, 62, 67,
070.079: 77, 108, 122, 37, 60, 66, 121, 42, 51, 126,
080.089: 117, 114, 4, 90, 43, 52, 53, 113, 120, 72,
090.099: 16, 49, 7, 79, 119, 61, 22, 84, 9, 97,
100.109: 91, 15, 21, 24, 46, 39, 93, 105, 65, 70,
110.113: 125, 99, 17, 123,
The hopping sequence generation algorithm is represented diagrammatically in figure 6.
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6.2.4 Specific cases
On the RFCH carrying a BCCH (C0), frequency hopping is not permitted on any timeslot supporting a
BCCH according to table 3 of clause 7. A non-hopping radio frequency channel sequence is characterized
by a mobile allocation consisting of only one radio frequency channel, i.e. with N=1, MAIO=0. In this
instance sequence generation is unaffected by the value of the value HSN.
6.2.5 Change in the frequency allocation of a base transceiver station
The consequence of adding or removing a number of radio frequency channels in a base transceiver
station is a modification of the cell allocation (CA) and the mobile allocation (MA). In order to achieve this
without disruption to mobile stations with currently assigned channels it is necessary to send a message to
all mobiles with assigned channels. The message, as defined in 04.08, will contain a new cell allocation (if
necessary), mobile allocation and a time (in the form of a TDMA frame number) at which the change is to
occur. A new cell allocation may not be necessary if channels are only being removed, and not added.
6.3 Mapping in time of logical channels onto physical channels
6.3.1 General
The mapping in time of logical channels is defined in the tables of clause 7, which also defines the
relationship of the air interface frames to the multiframe.
6.3.2 Key to the mapping table of clause 7
The following relates to the tables of clause 7. The columns headed:
i) "Channel designation" gives the precise acronym for the channel to which the mapping
applies.
ii) "Sub-channel number" identifies the particular sub-channel being defined where a basic
physical channel supports more than one channel of this type.
iii) "Direction" defines whether the mapping given applies identically to downlink and uplink
(D&U), or to down
...
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