ETSI ETS 300 575 ed.3 (1997-08)

SLOVENSKI STANDARD
SIST ETS 300 575 E3:2003
01-december-2003
'LJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHPID]D±.RGLUDQMHNDQDORY*60
UD]OLþLFD
Digital cellular telecommunications system (Phase 2) (GSM); Channel coding (GSM
05.03 version 4.4.1)
Ta slovenski standard je istoveten z: ETS 300 575 Edition 3
ICS:
33.070.50 Globalni sistem za mobilno Global System for Mobile
telekomunikacijo (GSM) Communication (GSM)
35.040 Nabori znakov in kodiranje Character sets and
informacij information coding
SIST ETS 300 575 E3:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 575 E3:2003

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SIST ETS 300 575 E3:2003
EUROPEAN ETS 300 575
TELECOMMUNICATION August 1997
STANDARD Third Edition
Source: ETSI SMG Reference: RE/SMG-020503PR3
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);
Channel coding
(GSM 05.03 version 4.4.1)
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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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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Contents
Foreword .5
1 Scope .7
1.2 Normative references.7
1.3 Definitions and abbreviations .8
2 General.8
2.1 General Organization.8
2.2 Naming Convention .10
3 Traffic Channels (TCH) .10
3.1 Speech channel at full rate (TCH/FS).10
3.1.1 Parity and tailing for a speech frame.11
3.1.2 Convolutional encoder.11
3.1.3 Interleaving.11
3.1.4 Mapping on a Burst .12
3.2 Speech channel at half rate (TCH/HS) .12
3.2.1 Parity and tailing for a speech frame.12
3.2.2 Convolutional encoder.13
3.2.3 Interleaving.13
3.2.4 Mapping on a burst.14
3.3 Data channel at full rate, 12.0 kbit/s radio interface rate (9.6 kbit/s services
(TCH/F9.6)).14
3.3.1 Interface with user unit .14
3.3.2 Block code.14
3.3.3 Convolutional encoder.14
3.3.4 Interleaving.15
3.3.5 Mapping on a Burst .15
3.4 Data channel at full rate, 6.0 kbit/s radio interface rate (4.8 kbit/s services (TCH/F4.8)) .15
3.4.1 Interface with user unit .15
3.4.2 Block code.15
3.4.3 Convolutional encoder.16
3.4.4 Interleaving.16
3.4.5 Mapping on a Burst .16
3.5 Data channel at half rate, 6.0 kbit/s radio interface rate (4.8 kbit/s services (TCH/H4.8)) 16
3.5.1 Interface with user unit .16
3.5.2 Block code.16
3.5.3 Convolutional encoder.16
3.5.4 Interleaving.16
3.5.5 Mapping on a Burst .16
3.6 Data channel at full rate, 3.6 kbit/s radio interface rate (2.4 kbit/s and less services
(TCH/F2.4)).16
3.6.1 Interface with user unit .16
3.6.2 Block code.17
3.6.3 Convolutional encoder.17
3.6.4 Interleaving.17
3.6.5 Mapping on a Burst .17
3.7 Data channel at half rate, 3.6 kbit/s radio interface rate (2.4 kbit/s and less services
(TCH/H2.4)) .17
3.7.1 Interface with user unit .17
3.7.2 Block code.17
3.7.3 Convolutional encoder.17
3.7.4 Interleaving.18
3.7.5 Mapping on a Burst .18

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4 Control Channels. 18
4.1 Slow associated control channel (SACCH). 18
4.1.1 Block constitution. 18
4.1.2 Block code . 18
4.1.3 Convolutional encoder . 18
4.1.4 Interleaving . 19
4.1.5 Mapping on a Burst. 19
4.2 Fast associated control channel at full rate (FACCH/F). 19
4.2.1 Block constitution. 19
4.2.2 Block code . 19
4.2.3 Convolutional encoder . 19
4.2.4 Interleaving . 19
4.2.5 Mapping on a Burst. 19
4.3 Fast associated control channel at half rate (FACCH/H) . 20
4.3.1 Block constitution. 20
4.3.2 Block code . 20
4.3.3 Convolutional encoder . 20
4.3.4 Interleaving . 20
4.3.5 Mapping on a Burst. 20
4.4 Broadcast, Paging, Access grant and Cell broadcast channels (BCCH, PCH, AGCH,
CBCH). 21
4.5 Stand-alone dedicated control channel (SDCCH). 21
4.6 Random access channel (RACH) . 21
4.7 Synchronization channel (SCH) . 22
4.8 Handover Access Burst. 22
Annex A (informative): Summary of Channel Types . 28
Annex B (informative): Summary of Polynomials Used for Convolutional Codes . 29
History. 30

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Foreword
This European Telecommunications Standard (ETS) has been produced by the Special Mobile Group
(SMG) of the European Telecommunications Standards Institute (ETSI).
This ETS specifies the channel coding of used within the digital cellular telecommunications system
(Phase 2).
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/PNE Rules.
Transposition dates
Date of adoption: 25 July 1997
Date of latest announcement of this ETS (doa): 30 November 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 May 1998
Date of withdrawal of any conflicting National Standard (dow): 31 May 1998

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1 Scope
A reference configuration of the transmission chain is shown in GSM 05.01. According to this reference
configuration, this technical specification specifies the data blocks given to the encryption unit.
It includes the specification of encoding, reordering, interleaving and the stealing flag. It does not specify
the channel decoding method.
The definition is given for each kind of logical channel, starting from the data provided to the channel
encoder by the speech coder, the data terminal equipment, or the controller of the MS or BS. The
definitions of the logical channel types used in this technical specification are given in GSM 05.02, a
summary is in annex A.
1.2 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 100): "Digital cellular telecommunications system (Phase 2);
Abbreviations and acronyms".
[2] GSM 04.08 (ETS 300 557): "Digital cellular telecommunications system
(Phase 2); Mobile radio interface layer 3 specification".
[3] GSM 04.21 (ETS 300 562): "Digital cellular telecommunications system
(Phase 2); Rate adaption on the Mobile Station - Base Station System (MS -
BSS) interface ".
[4] GSM 05.01 (ETS 300 573): "Digital cellular telecommunications system
(Phase 2); Physical layer on the radio path General description".
[5] GSM 05.02 (ETS 300 574): "Digital cellular telecommunications system
(Phase 2); Multiplexing and multiple access on the radio path".
[6] GSM 05.05: (ETS 300 577): "Digital cellular telecommunications system
(Phase 2); Radio Transmission and Reception".
[7] GSM 06.10 (ETS 300 580-2): "Digital cellular telecommunications system
(Phase 2); Full rate speech transcoding".
[8] GSM 06.20 (ETS 300 581-2): "Digital cellular telecommunications system; Half
rate speech Part 2: Half rate speech transcoding".

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1.3 Definitions and abbreviations
Abbreviations used in this ETS are listed in GSM 01.04.
2 General
2.1 General Organization
Each channel has its own coding and interleaving scheme. However, the channel coding and interleaving
is organized in such a way as to allow, as much as possible, a unified decoder structure.
Each channel uses the following sequence and order of operations:
- The information bits are coded with a systematic block code,uilding words of information + parity
bits.
- These information + parity bits are encoded with a convolutional code, building the coded bits.
- Reordering and interleaving the coded bits, and adding a stealing flag, gives the interleaved bits.
All these operations are made block by block, the size of which depends on the channel. However, most
of the channels use a block of 456 coded bits which is interleaved and mapped onto bursts in a very
similar way for all of them. Figure 1 gives a diagram showing the general structure of the channel coding.
This block of 456 coded bits is the basic structure of the channel coding scheme. In the case of full rate
speech TCH, this block carries the information of one speech frame. In case of control channels, it carries
one message.
In the case of half rate speech TCH, the information of one speech frame is carried in a block of
228 coded bits.
In the case of FACCH, a coded message block of 456 bits is divided into eight sub-blocks. The first four
sub-blocks are sent by stealing the even numbered bits of four timeslots in consecutive frames used for
the TCH. The other four sub-blocks are sent by stealing the odd numbered bits of the relevant timeslot in
four consecutive used frames delayed 2 or 4 frames relative to the first frame. Along with each block of
456 coded bits there is, in addition, a stealing flag (8 bits), indicating whether the block belongs to the TCH
or to the FACCH. In the case of SACCH, BCCH or CCCH, this stealing flag is dummy.
Some cases do not fit in the general organization, and use short blocks of coded bits which are sent
completely in one timeslot. They are the random access messages of the RACH on uplink and the
synchronization information broadcast of the SCH on downlink.

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TCH/FS
TCH/HS SACCH, FACCH,
(full rate
(half rate BCCH, CBCH, PCH RACH,
speech TCH)
speech TCH) AGCH, SDCCH data TCHs SCH
speech fram e speech fram e data fram e
m essage m essage
112 bits 260 bits N0 bits
184 bits P0 bits
3.2 3.1 3.n.1
4.1.1 4.6, 4.7
interface
1
cyclic code cyclic code cyclic code
Fire code
+tail
+ tail + tail + tail
+tail
in: N0 bits
in: 112 bits in: 260 bits in: P0 bits
in: 184 bits
out: N1 bits
out: 121 bits out: P1 bits
out: 267 bits
out: 228 bits
3.n.2
3.2.1 3.1.1 4.6, 4.7
4.1.2
interface
2
convolutional convolutional
convolutional convolutional convolutional
code
code
code code code
k=7, 2 classes k=5, 2 classes
k=5, rate 1/2 k=5, rate r k=5, rate 1/2
in: 121 bits
in: 267 bits
in: 228 bits in: N1 bits in: P1 bits
out: 228 bits out: 456 bits
out: 456 bits out: 456 bits out: 2*P1 bits
3.2.2
3.1.2
4.1.3 3.n.3 4.6, 4.7
interface
3
TCH/F2.4 others
reordering and partitioning
reordering and partitioning
+stealing flag +stealing flag
in: 456 bits
in: 228 bits
diagonal interleaving
out: 4 blocks out: 8 blocks
+ stealing flags
3.1.3, 4.1.4, 4.3.4
3.2.3
in: 456 bits
out: 4 blocks
TCH/FS, FACCH others
diagonally interleaved
TCH/F2.4
to depth 19, starting
on consecutive bursts
block diagonal block diagonal
block rectangular
3.n.4
interleaving interleaving
interleaving
in: 4 blocks in: 8 blocks
in: 8 blocks
out: pairs of out: pairs of
out: pairs of
blocks blocks
blocks
3.2.3 3.1.3, 4.3.4
4.1.4
interface
4
encryption unit
Figure 1: Channel Coding and Interleaving Organization
In each box, the last line indicates the chapter defining the function. In the case of RACH, P0=8 and
P1=18; in the case of SCH, P0=25 and P1=39. In the case of data TCHs, N0, N1 and n depend on
the type of data TCH.
Interfaces:
1) information bits (d);
2) information + parity + tail bits (u);
3) coded bits (c);
4) interleaved bits (e).

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2.2 Naming Convention
For ease of understanding a naming convention for bits is given for use throughout the technical
specification:
- General naming
"k" and "j" for numbering of bits in data blocks and bursts;
"K " gives the amount of bits in one block, where "x" refers to the data type;
x
"n" is used for numbering of delivered data blocks where;
"N" marks a certain data block;
"B" is used for numbering of bursts or blocks where;
"B " marks the first burst or block carrying bits from the data block with n = 0 (first data block in the
0
transmission).
- Data delivered to the encoding unit (interface 1 in figure 1):
d(k) for k = 0,1,.,K - 1
d
- Data after the first encoding step (block code, cyclic code; interface 2 in figure 1):
u(k) for k = 0,1,.,K - 1
u
- Data after the second encoding step (convolutional code ; interface 3 in figure 1):
c(n,k) or c(k) for k = 0,1,.,K - 1
c
n = 0,1,.,N,N + 1,.
- Interleaved data:
i(B,k) for k = 0,1,.,K - 1
i
B = B , B +1,.
0 0
- Bits in one burst (interface 4 in figure 1):
e(B,k) for k = 0,1,.,114,115
B = B , B + 1,.
0 0
3 Traffic Channels (TCH)
Two kinds of traffic channel are considered: speech and data. Both of them use the same general
structure (see figure1), and in both cases, a piece of information can be stolen by the FACCH.
3.1 Speech channel at full rate (TCH/FS)
The speech coder delivers to the channel encoder a sequence of blocks of data. In case of a full rate
speech TCH, one block of data corresponds to one speech frame. Each block contains 260 information
bits, including 182 bits of class 1 (protected bits), and 78 bits of class 2 (no protection), (see table 2).
The bits delivered by the speech coder are received in the order indicated in GSM 06.10 and have to be
rearranged according to table 2 before channel coding as defined in 3.1.1 to 3.1.4. The rearranged bits
are labelled {d(0),d(1),.,d(259)}, defined in the order of decreasing importance.

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3.1.1 Parity and tailing for a speech frame
a) Parity bits:
The first 50 bits of class 1 are protected by three parity bits used for error detection. These parity
bits are added to the 50 bits, according to a degenerate (shortened) cyclic code (53,50,2), using the
generator polynomial:
3
g(D) = D + D + 1
The encoding of the cyclic code is performed in a systematic form, which means that, in GF(2), the
polynomial:
52 51 3 2
d(0)D + d(1)D +. + d(49)D + p(0)D + p(1)D + p(2)
where p(0), p(1), p(2) are the parity bits, when divided by g(D), yields a remainder equal to:
2
1 + D + D
b) Tailing bits and reordering:
The information and parity bits of class 1 are reordered, defining 189 information + parity + tail bits
of class 1, {u(0),u(1),.,u(188)} defined by:
u(k) = d(2k) and u(184-k) = d(2k+1) for k = 0,1,.,90
u(91+k) = p(k) for k = 0,1,2
u(k) = 0 for k = 185,186,187,188 (tail bits)
3.1.2 Convolutional encoder
The class 1 bits are encoded with the 1/2 rate convolutional code defined by the polynomials:
3 4
G0 = 1 + D + D
3 4
G1 = 1 + D + D + D
The coded bits {c(0), c(1),., c(455)} are then defined by:
- class 1 : c(2k) = u(k) + u(k-3) + u(k-4)
c(2k+1) = u(k) + u(k-1) + u(k-3) + u(k-4) for k = 0,1,.,188
u(k) = 0 for k < 0
- class 2 : c(378+k) = d(182+k) for k = 0,1,.,77
3.1.3 Interleaving
The coded bits are reordered and interleaved according to the following rule:
i(B,j) = c(n,k), for k = 0,1,.,455
n = 0,1,.,N,N+1,.
B = B + 4n + (k mod 8)
0
j = 2((49k) mod 57) + ((k mod 8) div 4)
See table 1. The result of the interleaving is a distribution of the reordered 456 bits of a given data block,
n = N, over 8 blocks using the even numbered bits of the first 4 blocks (B = B + 4N + 0, 1, 2, 3) and odd
0
numbered bits of the last 4 blocks (B = B + 4N + 4, 5, 6, 7). The reordered bits of the following data
0
block, n = N + 1, use the even numbered bits of the blocks B = B + 4N + 4, 5, 6, 7 (B = B + 4(N+1) + 0,
0 0
1, 2, 3) and the odd numbered bits of the blocks B = B + 4(N+1) + 4, 5, 6, 7. Continuing with the next
0
data blocks shows that one block always carries 57 bits of data from one data block (n = N) and 57 bits of
data from the next block (n = N+1), where the bits from the data block with the higher number always are
the even numbered data bits, and those of the data block with the lower number are the odd numbered
bits.

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th
The block of coded data is interleaved "block diagonal", where a new data block starts every 4 block and
is distributed over 8 blocks.
3.1.4 Mapping on a Burst
The mapping is given by the rule:
e(B,j) = i(B,j) and e(B,59+j) = i(B,57+j) for j = 0,1,.,56
and
e(B,57) = hl(B) and e(B,58) = hu(B)
The two bits, labelled hl(B) and hu(B) on burst number B are flags used for indication of control channel
signalling. For each TCH/FS block not stolen for signalling purposes:
hu(B )= 0 for the first 4 bursts (indicating status of even numbered bits)
hl(B) = 0 for the last 4 bursts (indicating status of odd numbered bits)
For the use of hl(B) and hu(B) when a speech frame is stolen for signalling purposes see subclause 4.2.5.
3.2 Speech channel at half rate (TCH/HS)
The speech coder delivers to the channel encoder a sequence of blocks of data. In case of a half rate
speech TCH, one block of data corresponds to one speech frame. Each block contains 112 bits, including
95 bits of class 1 (protected bits), and 17 bits of class 2 (no protection), see tables 3a and 3b.
The bits delivered by the speech coder are received in the order indicated in GSM 06.20 and have to be
arranged according to either table 3a or table 3b before channel encoding as defined in subclauses 3.2.1
to 3.2.4. The rearranged bits are labelled {d(0),d(1),.,d(111)}. Table 3a has to be taken if parameter
Mode = 0 (which means that the speech encoder is in unvoiced mode), while table 3b has to be taken if
parameter Mod e = 1, 2 or 3 (which means that the speech encoder is in voiced mode).
3.2.1 Parity and tailing for a speech frame
a) Parity bits:
The most significant 22 class 1 bits d(73),d(74),.,d(94) are protected by three parity bits used for
error detection. These bits are added to the 22 bits, according to a cyclic code using the generator
polynomial:
3
g(D) = D + D + 1
The encoding of the cyclic code is performed in a systematic form, which means that, in GF(2), the
polynomial:
24 23 3 2
d(73)D + d(74)D + . + d(94)D + p(0)D + p(1)D + p(2)
where p(0), p(1), p(2) are the parity bits, when divided by g(D), yields a remainder equal to:
2
1 + D + D .
b) Tail bits and reordering:
The information and parity bits of class 1 are reordered, defining 104 information + parity + tail bits
of class 1, {u(0),u(1),.,u(103)} defined by:
u(k) = d(k) for k = 0,1,.,94
u(k) = p(k-95) for k = 95,96,97
u(k) = 0 for k = 98,99,.,103 (tail bits)

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3.2.2 Convolutional encoder
The class 1 bits are encoded with the punctured convolutional code defined by the mother polynomials:
2 3 5 6
G4 = 1 + D + D + D + D
4 6
G5 = 1 + D + D + D
2 3 4 6
G6 = 1 + D + D + D + D + D
and the puncturing matrices:
(1,0,1) for {u(0),u(1),.,u(94)} (class 1 information bits);
and {u(98),u(99),.,u(103)} (tail bits).
(1,1,1) for {u(95),u(96),u(97)} (parity bits)
In the puncturing matrices, a 1 indicates no puncture and a 0 indicates a puncture.
The coded bits {c(0),c(1),.,c(227)} are then defined by:
class 1 information bits:
c(2k) = u(k)+u(k-2)+u(k-3)+u(k-5)+u(k-6)
c(2k+1) = u(k)+u(k-1)+u(k-2)+u(k-3)+u(k-4)+u(k-6) for k = 0,1,.,94;u(k) = 0 for k<0
parity bits:
c(3k-95) = u(k)+u(k-2)+u(k-3)+u(k-5)+u(k-6)
c(3k-94) = u(k)+u(k-1)+u(k-4)+u(k-6)
c(3k-93) = u(k)+u(k-1)+u(k-2)+u(k-3)+u(k-4)+u(k-6) for k = 95,96,97
tail bits:
c(2k+3) = u(k)+u(k-2)+u(k-3)+u(k-5)+u(k-6)
c(2k+4) = u(k)+u(k-1)+u(k-2)+u(k-3)+u(k-4)+u(k-6) for k = 98,99,.,103
class 2 information bits:
c(k+211) = d(k+95) for k = 0,1,.,16
3.2.3 Interleaving
The coded bits are reordered and interleaved according to the following rule:
i(B,j) = c(n,k) for k = 0,1,.,227
n = 0,1,.,N,N+1,.
B = B0 + 2n + b
The values of b and j in dependence of k are given by table 4.
The result of the interleaving is a distribution of the reordered 228 bits of a given data block, n = N, over
4 blocks using the even numbered bits of the first 2 blocks (B = B0+2N+0,1) and the odd numbered bits of
the last 2 blocks (B = B0+2N+2,3). The reordered bits of the following data block, n = N + 1, use the even
numbered bits of the blocks B = B0 + 2N + 2,3 (B = B0+2(N+1)+0,1) and the odd numbered bits of the
blocks B = B0 + 2(N+1)+2,3. Continuing with the next data blocks shows that one block always carries
57 bits of data from one data block (n = N) and 57 bits from the next block (n = N+1), where the bits from
the data block with the higher number always are the even numbered data bits, and those of the data
block with the lower number are the odd numbered bits. The block of coded data is interleaved "block
nd
diagonal", where a new data block starts every 2 block and is distributed over 4 blocks.

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3.2.4 Mapping on a burst
The mapping is given by the rule:
e(B,j) = i(B,j) and e(B,59+j) = i(B,57+j) for j = 0,1,.,56
and
e(B,57) = hl(B) and e(B,58) = hu(B)
The two bits, labelled hl(B) and hu(B) on burst number B are flags used for indication of control channel
signalling. For each TCH/HS block not stolen for signalling purposes:
hu(B) = 0 for the first 2 bursts (indicating status of the even numbered bits)
hl(B) = 0 for the last 2 bursts (indicating status of the odd numbered bits)
For the use of hl(B
...