Digital audio - Digital input-output interfacing - Transmission of digital audio over asynchronous transfer mode (ATM) networks (IEC 62365:2009)

This International Standard specifies a means to carry multiple channels of audio in linear PCM or IEC 60958-4 format over an ATM layer service conforming to ITU-T Recommendation I.150. It includes a means to convey, between parties, information concerning the digital audio signal when setting up audio calls across the ATM network. It does not specify the physical interface to the network.

Digitalton - Digitale Ein-/Ausgangsschnittstellen - Übertragung von Digitalton über ATM-Netzwerke (IEC 62365:2009)

Audionumérique - Interface numérique d'entrée-sortie - Transmission de l'audionumérique sur les réseaux à mode de transfert asynchrone (ATM) (CEI 62365:2009)

La CEI 62365:2009 spécifie un moyen de transporter plusieurs canaux audio dans un format MIC ou CEI 60958-4 sur un service de couche ATM conforme à la Recommandation UIT-T I.150. Elle inclut un moyen d'acheminer, entre les participants, des informations concernant le signal audionumérique lors de l'établissement d'appels audio à travers le réseau ATM. La présente version bilingue (2012-08) correspond à la version anglaise monolingue publiée en 2009. Cette seconde édition de la CEI 62365 annule et remplace la première édition parue en 2004. Les principales modifications par rapport à l'édition précédente (2004) sont: la suppression des deuxième, troisième et quatrième formats requis en 4.3. et le reformatage de 4.3, la suppression du Tableau 2 et la renumérotation des tableaux ultérieurs.

Digitalni avdio - Digitalni vhodno/izhodni vmesnik - Prenos digitalnih avdio signalov prek omrežij z asinhronim prenosnim načinom (IEC 62365:2009)

General Information

Status
Published
Publication Date
20-Sep-2009
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
03-Aug-2009
Due Date
08-Oct-2009
Completion Date
21-Sep-2009

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SLOVENSKI STANDARD
SIST EN 62365:2009
01-oktober-2009
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SIST EN 62365:2006
'LJLWDOQLDYGLR'LJLWDOQLYKRGQRL]KRGQLYPHVQLN3UHQRVGLJLWDOQLKDYGLR
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Digital audio - Digital input-output interfacing - Transmission of digital audio over

asynchronous transfer mode (ATM) networks (IEC 62365:2009)

Digitalton - Digitale Ein-/Ausgangsschnittstellen - Übertragung von Digitalton über ATM-

Netzwerke (IEC 62365:2009)
Audionumérique - Interface numérique d'entrée-sortie - Transmission de
l'audionumérique sur les réseaux à mode de transfert asynchrone (ATM) (CEI
62365:2009)
Ta slovenski standard je istoveten z: EN 62365:2009
ICS:
33.160.30 Avdio sistemi Audio systems
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
SIST EN 62365:2009 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 62365:2009
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SIST EN 62365:2009
EUROPEAN STANDARD
EN 62365
NORME EUROPÉENNE
July 2009
EUROPÄISCHE NORM
ICS 35.200; 33.160 Supersedes EN 62365:2005
English version
Digital audio -
Digital input-output interfacing -
Transmission of digital audio
over asynchronous transfer mode (ATM) networks
(IEC 62365:2009)
Audionumérique - Digitalton -
Interface numérique d'entrée-sortie - Digitale Ein-/Ausgangsschnittstellen -
Transmission de l'audionumérique Übertragung von Digitalton
sur les réseaux à mode über ATM-Netzwerke
de transfert asynchrone (ATM) (IEC 62365:2009)
(CEI 62365:2009)

This European Standard was approved by CENELEC on 2009-06-01. CENELEC members are bound to comply

with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard

the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on

application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CENELEC member into its own language and notified

to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the

Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,

Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: Avenue Marnix 17, B - 1000 Brussels

© 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 62365:2009 E
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SIST EN 62365:2009
EN 62365:2009 – 2 –
Foreword

The text of document 100/1517/FDIS, future edition 2 of IEC 62365, prepared by technical area 4, Digital

systems interfaces and protocols, of IEC TC 100, Audio, video and multimedia systems and equipment,

was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 62365 on

2009-06-01.
This European Standard supersedes EN 62365:2005.
The main changes with respect to EN 62365:2005 are listed below:
– second, third and fourth required formats in 4.3 removed;
– 4.3 reformatted, eliminating Table 2, and subsequent tables renumbered.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2010-03-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2012-06-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice

The text of the International Standard IEC 62365:2009 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following note has to be added for the standard indicated:

IEC 60027-2 NOTE Harmonized as EN 60027-2:2007 (not modified).
__________
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SIST EN 62365:2009
– 3 – EN 62365:2009
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the referenced

document (including any amendments) applies.

NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD

applies.
Publication Year Title EN/HD Year
1) 2)
IEC 60958-1 - Digital audio interface - EN 60958-1 2008
Part 1: General
1) 2)
IEC 60958-4 - Digital audio interface - EN 60958-4 2003
Part 4: Professional applications (TA4)
ITU-T - B-ISDN asynchronous transfer mode - -
Recommendation functional characteristics
I.150
ITU-T - B-ISDN ATM Adaptation Layer specification: - -
Recommendation Type 5 AAL
I.363.5
ITU-T - Digital Subscriber Signalling System No. 2 - - -
Recommendation User-Network Interface (UNI) layer 3
Q.2931 specification for basic call/connection control
Undated reference.
Valid edition at date of issue.
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SIST EN 62365:2009
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SIST EN 62365:2009
IEC 62365
Edition 2.0 2009-05
INTERNATIONAL
STANDARD
Digital audio – Digital input-output interfacing – Transmission of digital audio
over asynchronous transfer mode (ATM) networks
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
ICS 35.200, 33.160 ISBN 2-8318-1040-8
® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 7 ----------------------
SIST EN 62365:2009
– 2 – 62365 © IEC:2009(E)
CONTENTS

FOREWORD...........................................................................................................................4

INTRODUCTION.....................................................................................................................6

1 Scope...............................................................................................................................8

2 Normative references .......................................................................................................8

3 Terms and definitions .......................................................................................................8

4 Format of audio data in ATM cells ..................................................................................10

4.1 Format of audio samples .......................................................................................10

4.1.1 Subframes.................................................................................................10

4.1.2 Audio sample word ....................................................................................10

4.1.3 Ancillary data ............................................................................................10

4.1.4 Protocol overhead .....................................................................................10

4.2 Packing of sample data into cells ..........................................................................12

4.2.1 Packing schemes ......................................................................................12

4.2.2 Temporal grouping ....................................................................................12

4.2.3 Multi-channel.............................................................................................12

4.2.4 Grouping by channel..................................................................................13

4.3 Formats.................................................................................................................13

4.4 ATM adaptation layer ............................................................................................13

4.5 ATM-user-to-ATM-user indication ..........................................................................13

5 Switched virtual circuits ..................................................................................................14

5.1 Addresses .............................................................................................................14

5.2 Audio call connection: SETUP and ADD PARTY messages ...................................14

5.2.1 Restrictions on connection requests ..........................................................14

5.2.2 Information elements in the SETUP and ADD PARTY messages ...............14

5.2.3 Destination response to SETUP and ADD PARTY messages.....................15

5.3 Call disconnection .................................................................................................16

6 Coding of audio formats .................................................................................................16

6.1 Qualifying information............................................................................................16

6.2 Subframe format....................................................................................................17

6.3 Packing of subframes into cells .............................................................................17

6.4 Sampling frequency...............................................................................................18

7 Permanent virtual circuits ...............................................................................................18

8 Management interface ....................................................................................................19

8.1 Call connection: SETUP messages .......................................................................19

8.1.1 Restrictions on connection requests ..........................................................19

8.1.2 Information elements in the SETUP message ............................................19

8.1.3 Destination response to SETUP message..................................................20

8.2 Message encapsulation .........................................................................................20

8.3 Message format and action to be taken by recipient ..............................................20

8.4 Message types ......................................................................................................21

8.4.1 Messages sent from the controlling entity ..................................................21

8.4.2 Messages sent to the controlling entity ......................................................23

8.4.3 Vendor-specific messages.........................................................................25

Annex A (informative) Data protection..................................................................................26

Annex B (informative) Application identifier values...............................................................28

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SIST EN 62365:2009
62365 © IEC:2009(E) – 3 –

Bibliography..........................................................................................................................29

Table 1 – Fields contained in a subframe..............................................................................10

Table 2 – Default port number and packing for certain VCIs..................................................19

Table 3 – Status enquiry message ........................................................................................21

Table 4 – Audio connection request message .......................................................................22

Table 5 – Audio disconnection request message...................................................................22

Table 6 – Input port status message .....................................................................................23

Table 7 – Output port status message...................................................................................24

Table 8 – Other status messages..........................................................................................25

Table 9 – Vendor-specific messages.....................................................................................25

Table A.1 – Sequence number protection field values ...........................................................26

Table B.1 – Application identifier (octets 9 to 12) values in the BHLI IE ................................28

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SIST EN 62365:2009
– 4 – 62365 © IEC:2009(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
DIGITAL AUDIO –
DIGITAL INPUT-OUTPUT INTERFACING –
TRANSMISSION OF DIGITAL AUDIO OVER
ASYNCHRONOUS TRANSFER MODE (ATM) NETWORKS
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence

between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

the latter.

5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any

equipment declared to be in conformity with an IEC Publication.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 62365 has been prepared by technical area 4: Digital systems

interfaces and protocols, of IEC technical committee 100: Audio, video and multimedia

systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100/1517/FDIS 100/1550/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

---------------------- Page: 10 ----------------------
SIST EN 62365:2009
62365 © IEC:2009(E) – 5 –
The main changes with respect to the previous edition (2004) are listed below.
– Second, third, and fourth required formats in 4.3 removed.
– 4.3 reformatted, eliminating Table 2, and subsequent Tables renumbered.

The committee has decided that the contents of this publication will remain unchanged until

the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in

the data related to the specific publication. At this date, the publication will be

• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
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SIST EN 62365:2009
– 6 – 62365 © IEC:2009(E)
INTRODUCTION

This International Standard describes means for the transmission of professional audio across

digital networks, including metropolitan- and wide-area networks, to provide the best

performance with regard to latency, jitter, and other relevant factors.

Current-generation wide-area communications are based on two very similar systems,

synchronous optical network (SONET) and synchronous digital hierarchy (SDH), SONET being

used in the United States and SDH in Europe. On top of them are run integrated services digital

network (ISDN), asynchronous transfer mode (ATM), and Internet protocol (IP).

ISDN provides telephone call connections of a fixed capacity that carry one 8-bit value per

125 μs; when a call is set up, its route through the system is chosen, and the switches that

route the data are configured accordingly. Each link, between switches or between switch and

end equipment, is formatted into frames that take 125 μs to transmit, and each data byte is

identified by its position in the frame.

ATM, also called broadband ISDN, provides a service similar to ISDN, but with the capacity of

each call being specified by the caller. Links are formatted into cells, which consist of a

header and 48 data bytes; the header is typically 5 bytes long, and most of it is taken up with

the virtual channel identifier (VCI) that shows to which call the cell belongs. Call set-up,

routeing, and switching are done in the same way as in ISDN, but with calls not being

restricted to 1 byte every 125 μs.

IP provides a very different service, not designed for continuous media such as audio and

video. There is no call set-up, and each packet contains enough information within itself to

allow it to be routed to its destination. This means that the header is much larger than in the

case of ATM, typically 74 bytes, and packets will also typically be much larger, if only

because otherwise the overheads would be excessive. Each packet is liable to be routed

separately, so two packets that are part of the same flow may well take different routes. This

can mean that the one that was sent first does not arrive first.

For many professional audio applications, a round-trip time from the microphone through the

mixing desk and back to the headphones of no more than 3 ms is required. Allowing 0,5 ms

each for conversion from analog to digital and back again, it follows that the network

connections to and from the mixing desk must have a latency of less than 1 ms each. For

distances of more than about 200 km, the transmission delay alone will exceed 1 ms, but

within a metropolitan area the transmission delay should be no more than 0,25 ms (equivalent

to about 50 km), leaving 0,75 ms for packetization, queuing within switches, and
resynchronization within the receiving equipment.

Packetization delays are proportional to the size of the transmission unit (frame, cell, or

packet), and resynchronization delays depend on how evenly spaced the transmission units

are when they arrive at their destination. Both classes of delay are thus small for ISDN and

large for IP. Using the format specified in this standard to carry dual-channel IEC 60958-4

audio with a 48 kHz sampling frequency over ATM results in an inter-cell time of 125 μs, at

which ATM will have similar delays to ISDN. A higher sampling frequency or a larger number

of channels would reduce the inter-cell time and hence also the delays.

The queuing time within each ISDN switch is likely to be around one frame time or 125 μs.

The ATM documents limit the queuing time in an ATM switch to approximately the inter-cell

time for the call, which, as with the other delays, translates into performance similar to that of

ISDN for dual-channel 48 kHz IEC 60958-4 audio and better for higher sampling frequencies

or larger numbers of channels.

The queuing time within an IP router for normal, best effort, Internet traffic is unbounded, and

if the router is congested, packets may simply be thrown away. Resource reservation protocol

(RSVP) (see Annex A) allows capacity to be reserved for a particular traffic flow, but it does

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SIST EN 62365:2009
62365 © IEC:2009(E) – 7 –

not guarantee that the packets will actually be routed over the links on which the capacity has

been reserved; if the flow is re-routed, it will only get a best effort service until a reservation

has been made on the new route, and it may not even be possible to make a reservation on

the new route at all.

ATM has therefore been chosen as providing a more convenient service than ISDN and

significantly better performance than IP, even when RSVP is used.

This standard does not specify a physical interface to the network because one of the

features of ATM is its ability to make a seamless connection between interfaces operating at a

wide variety of data rates and with different ways of encoding the ATM cells. Commonly used

interfaces provide 25,6 Mbit/s over category 3 structured wiring and 155,52 Mbit/s over

category-5 structured wiring or fibre-optic cable.

The physical layer section description and unique ATM abbreviations can be found in ATM

forum approved specifications. See the Bibliography.
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SIST EN 62365:2009
– 8 – 62365 © IEC:2009(E)
DIGITAL AUDIO –
DIGITAL INPUT-OUTPUT INTERFACING –
TRANSMISSION OF DIGITAL AUDIO OVER
ASYNCHRONOUS TRANSFER MODE (ATM) NETWORKS
1 Scope

This International Standard specifies a means to carry multiple channels of audio in linear

PCM or IEC 60958-4 format over an ATM layer service conforming to ITU-T Recommendation

I.150. It includes a means to convey, between parties, information concerning the digital audio

signal when setting up audio calls across the ATM network.
It does not specify the physical interface to the network.
2 Normative references

The following referenced documents are indispensable for the application of this document.

For dated references, only the edition cited applies. For undated references, the latest edition

of the referenced document (including any amendments) applies.
IEC 60958-1, Digital audio interface – Part 1: General
IEC 60958-4, Digital audio interface – Part 4: Professional applications (TA4)

ITU-T Recommendation I.150: B-ISDN asynchronous transfer mode functional characteristics

ITU-T Recommendation I.363.5, B-ISDN ATM Adaptation Layer specification: Type 5 AAL

ITU-T Recommendation Q.2931: Digital Subscriber Signalling System No. 2 – User-Network

Interface (UNI) layer 3 specification for basic call/connection control
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
asynchronous transfer mode
ATM
networking technology in which data are carried in 48-o cells

NOTE Octet (unit symbol, o) is defined as an 8-bit data element by IEC 60027-2, which is synonymous with byte

(unit symbol, B) whenever the term, byte, is restricted to 8-bit elements.
3.2
ATM adaptation layer
AAL

protocol layer that allows different services, such as packet transfer, to be provided on an

ATM network
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SIST EN 62365:2009
62365 © IEC:2009(E) – 9 –
3.3
ATM signaling

protocol that conveys connection management and other messages between an ATM network

and equipment attached to it
3.4
audio channel
path that carries one monophonic digital audio signal
3.5
audio port
physical or virtual connector that carries a fixed number of audio channels
3.6
information element
component of an ATM signalling message
3.7
MADI
serial multi-channel audio digital interface
3.8
organizationally unique identifier
OUI

3-o code issued by a designated agency to form globally consistent bit strings as described in

OUI and company_id assignments
3.9
user-to-user indication

single bit in the ATM cell header that can be used by the ATM adaptation layer as a marker

for certain cells
3.10
virtual channel

communications channel that provides for the sequential unidirectional transport of ATM cells

on a link between two pieces of equipment
3.11
virtual channel identifier
VCI

numerical tag occupying a 16-bit field in the ATM cell header that identifies the virtual channel

over which the cell is to travel
3.12
virtual circuit
route through a network formed by concatenating virtual channels
3.13
virtual path
group of up to 65 536 virtual channels
3.14
virtual path identifier
VPI

numerical tag occupying an 8-bit field in the ATM cell header that identifies the virtual path

which contains the virtual channel over which the cell is to travel
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SIST EN 62365:2009
– 10 – 62365 © IEC:2009(E)
4 Format of audio data in ATM cells
4.1 Format of audio samples
4.1.1 Subframes

4.1.1.1 Each audio sample shall be encoded in a subframe that consists of a whole number

of octets. The subframe shall be stored in the cell in consecutive octets, with the first bit of the

subframe in the most significant bit of the first octet.

4.1.1.2 A subframe shall consist of the fields listed in Table 1, in the order in which they

appear.
Table 1 – Fields contained in a subframe
Field Specified in
Audio sample word 4.1.2
Ancillary data 4.1.3
Protocol overhead 4.1.4
4.1.2 Audio sample word

4.1.2.1 The audio sample shall be represented in linear 2’s complement form, with the most

significant bit first. If the source provides fewer bits than the size of this field, the unused least

significant bits shall be set to zero.

NOTE This specification is the same as in IEC 60958-4, except that the bit order is reversed.

4.1.2.2 The number of bits in the audio sample word shall be chosen in such a way that the

total number of bits in the subframe is 8, 16, 24, 32, or 48.
4.1.3 Ancillary data

4.1.3.1 This field shall either contain no bits or consist of four bits designated B, C, U, V, in

that order.

4.1.3.2 The C, U, and V bits shall be the channel status, user data, and validity bits specified

in IEC 60958-1.

4.1.3.3 The B bit shall be a 1 for the first subframe of the block specified in IEC 60958-1,

and a 0 for all other subframes.

NOTE The B bit affects the interpretation of the C bit, and possibly also of the U bit, but has no relation to the

grouping of samples specified in 4.2.

Where more than one audio channel is carried, the B bit shall be set at the start of the block

in every channel, not just in the first channel. The block starts may be unaligned.

4.1.4 Protocol overhead

This field shall either contain no bits or consist of a sequencing bit followed by three bits that

provide data protection.
4.1.4.1 Sequencing word

The sequencing word consists of the sequencing bits of all the subframes in a cell, in the

order in which the subframes appear in the cell.
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SIST EN 62365:2009
62365 © IEC:2009(E) – 11 –
4.1.4.1.1 Sequence number

The first four bits of the sequencing word shall contain a sequence number in the form of a

binary integer with the least significant bit first.

Except in the first cell transmitted on a virtual circuit, the value of this integer shall be 1 more

(modulo 16) than in the previous cell on the same virtual circuit.

The value of this integer in the first cell transmitted on each virtual circuit shall be chosen

such that in the first cell of each block, as specified in 4.5, the least significant three bits shall

be zero.

The value of the most significant bit in the first cell transmitted on each virtual circuit shall not

be defined in this standard.
4.1.4.1.2 Sequence number protection
The fifth to seventh bi
...

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