SIST ETS 300 283 E1:2003

• Abstract:

  Definition of harmonized loudness rating/echo values for the call path within a PBN, when accessing the PSTN (ISDN) via a digital interface, with a fully digital call path within the PSTN (or ISDN)

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.040.35 - Telephone networks
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI ETS 300 283 ed.1 (1994-04) - Business TeleCommunications (BTC); Planning of loudness rating and echo values for private networks digitally connected to the public network

SIST ETS 300 283 E1:2003 is the Slovenian version of ETS 300 283 Edition 1 from ETSI. It specifies planning values for loudness rating and echo in private branch networks (PBN) with digital access to the ISDN/PSTN. The document is meant for administrations and public or private network operators who design speech call paths between the Network Connection Point (NCP) and the public network.

What does SIST ETS 300 283 E1:2003 specify?

SIST ETS 300 283 E1:2003 applies to PBNs with digital access to the Integrated Services Digital Network (ISDN)/Public Switched Telephone Network (PSTN) and a fully 4-wire call path between the NCP and an International Switching Centre (ISC). It focuses on 3,1 kHz voice telephony call paths and gives planning targets for echo, stability and loudness so that speech quality remains acceptable at the network boundary.

The standard excludes diverted or extended calls inside the PBN after first answer when user-controlled features change the call path. It also excludes paths that contain mobile systems or cordless telephones, and it does not provide a compliance test specification. Where a compliance statement is made, the document expects supporting calculations and transmission performance data for the equipment involved.

Annex	What it covers
Annex A	Bibliography

The main body is organized into scope, normative references, definitions and abbreviations, reference configurations, echo control, stability and loudness ratings.

What are the key requirements of SIST ETS 300 283 E1:2003?

SIST ETS 300 283 E1:2003 sets design targets at the NCP rather than detailed test procedures. In practice, that means a network provider uses the document to plan transmission performance and decide when extra echo control is needed.

Echo control and transmission time

Clause 4.1 requires the private network to keep the mean one-way transmission time between the user apparatus and the NCP low enough for each possible call path without additional echo control in the PBN. The document allows higher values when national administrations set them, and it notes that acceptable additional echo control may be achieved by echo cancellation or by keeping the path wholly 4-wire to the acoustic interfaces.

For the reader, this means delay budgeting matters: the network designer must check the mean delay values of the relevant equipment and path segments, not only the cable route. If the delay target is exceeded, echo control has to be added.

Echo loss at the NCP

Clause 4.2 sets long-term and short-term echo loss objectives for the private network as seen at the NCP. The value is averaged across all possible call paths, so the operator must assess the network as a whole, not just one favored route. The text also says that if the delay limit is exceeded, or if echo loss falls too far below the target and cannot be increased, an echo control device should be used.

Stability

Clause 5 requires the stability loss seen from the NCP of each echo path to stay above the stated minimum across 200 Hz to 3 600 Hz. In practice, this is the anti-oscillation check: it helps prevent feedback problems in real speech circuits and is especially relevant where termination conditions vary.

Loudness ratings

Clause 6 gives long-term target values and short-term nominal ranges for Send Loudness Rating (SLR) and Receive Loudness Rating (RLR) at the NCP. The practical meaning is that the PBN should be planned so that speech is neither too quiet nor too loud, and so that the loudness design also supports echo performance. The clause also notes that lower loudness values may be allowed for existing telephones, but they should be avoided where possible because they increase echo risk.

What terms does SIST ETS 300 283 E1:2003 define?

• Network Connection Point (NCP) - the interconnection point between a PBN and an ISDN; it is the reference point for the planning limits.
• Private Branch Network (PBN) - a private telecommunication network together with the terminal equipment used for speech service.
• Overall Loudness Rating (OLR) - the total mouth-to-ear loudness loss over a connection; its additivity is important when checking sections of a path.
• Send Loudness Rating (SLR) - the loudness loss from the speaker’s mouth to the network interface.
• Receive Loudness Rating (RLR) - the loudness loss from the network interface to the listener’s ear.
• Talker’s Echo Loudness Rating (TELR) - the loudness loss from the speaker’s mouth back to the ear through the delayed echo path.
• Echo loss - a weighted loss measure used to judge echo performance in the network path.

Who uses SIST ETS 300 283 E1:2003?

Administrations, public network operators and private network operators use SIST ETS 300 283 E1:2003 when planning speech transmission between a PBN and the public network. It is also useful for network engineers, technical planners and quality managers who need to set loudness and echo targets, compare equipment performance, or prepare a compliance statement backed by calculations. Buyers and system specifiers use it to check whether a private network design is aimed at digital access to ISDN/PSTN voice traffic.

Which standards are used with SIST ETS 300 283 E1:2003?

• ETS 300 085 - provides handset terminal attachment requirements and is cited for the SLR and RLR values used in the echo-loss discussion.
• CCITT Recommendation G.122 - defines the basis for echo balance return loss and echo loss calculations.
• CCITT Recommendation G.131 - provides the stability and echo guidance used for the TELR-related assumptions.

What does the SIST ETS 300 283 E1:2003 document contain?

SIST ETS 300 283 E1:2003 contains definitions, abbreviations and reference configurations, plus planning rules for echo control, stability and loudness ratings. Figure 1 gives example reference configurations between terminals, analogue and digital paths, switches and the NCP, which helps the reader see where the limits apply. Clause 4 gives the transmission-time and echo-loss planning approach, clause 5 gives the stability criterion, and clause 6 gives the long-term and short-term loudness targets. Annex A lists supporting bibliography for further background on transmission and loudness rating methods.

SLOVENSKI STANDARD
01-december-2003
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RGPHYDY]DVHEQLKRPUHåMLKGLJLWDOQRYH]DQLKQDMDYQRRPUHåMH
Business TeleCommunications (BTC); Planning of loudness rating and echo values for
private networks digitally connected to the public network
Ta slovenski standard je istoveten z: ETS 300 283 Edition 1
ICS:
33.040.35 Telefonska omrežja Telephone networks
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 283
TELECOMMUNICATION April 1994
STANDARD
Source: ETSI TC-BTC Reference: DE/BTC-02003
ICS: 33.020.040.40
Loudness, echo, PTN, digital, interworking
Key words:
Business TeleCommunications (BTC);
Planning of loudness rating and echo values for private networks
digitally connected to the public network
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - [e-mail]
X.400: Internet:
Tel.: [phone] - Fax: [phone]
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 1994. All rights reserved.
New presentation - see History box

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ETS 300 283: April 1994
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 300 283: April 1994
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions, abbreviations and reference configurations .7
3.1 Definitions .7
3.2 Abbreviations .9
3.3 Reference configurations.10
4 Echo control .10
4.1 Transmission time.10
4.2 Echo loss of the private network at the NCP .11
5 Stability.11
6 Loudness ratings.11
Annex A (informative): Bibliography.12
History.13

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ETS 300 283: April 1994
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ETS 300 283: April 1994
Foreword
This European Telecommunication Standard (ETS) has been produced by the Business
TeleCommunications (BTC) Technical Committee of the European Telecommunications Standards
Institute (ETSI).
This ETS is a framework document which is intended for use by administrations, public and private
network operators. It deals with the transmission planning of Private Branch Networks (PBNs) with digital
access to the Integrated Services Digital Network (ISDN)/Public Switched Telephone Network (PSTN)
which send or receive speech telephone calls. It recognizes the overall responsibility of administrations for
ensuring that the quality of national communications is consistent with international quality objectives.
Public networks within Europe contain a mixture of analogue and digital equipment and there are
significant differences in the design of the analogue networks in different countries (e.g. different loudness
levels). In addition, although the public networks will eventually be very similar when they are fully digital,
the conversion from analogue to digital will be carried out in different ways and at different times in
different countries. During this conversion process, it may be possible to increase the impairment
allowances given to private networks and the greatest possible flexibility in this respect is desirable.
This ETS relates only to calls which pass through a public switched network to an International Switching
Centre (ISC). In the case of other calls (e.g. national calls) it may be possible for the impairment
allowances for private networks to be increased.
The approach followed is to specify the performance of a private network at the point or points where it is
connected to a public network. This approach may also be used for private networks that include
international leased circuits, provided that the performance at the connection point is maintained.
However, the approach to more complex topologies using international leased circuits is for further study.

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ETS 300 283: April 1994
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ETS 300 283: April 1994
1 Scope
This ETS is related to Private Branch Networks (PBNs) with a digital access to the Integrated Services
Digital Network (ISDN)/Public Switched Telephone Network (PSTN) with a fully 4-wire call path between
the Network Connection Point (NCP) and an International Switching Centre (ISC). It applies to call paths
carrying 3,1 kHz voice telephony between the NCP and the terminal in the PBN that sets up or answers
the call. If a call, before or after it is first answered, is diverted or extended within the PBN, by means of a
user-controlled feature, the extended call path is outside the scope of this ETS.
This ETS does not contain a compliance test specification. A compliance test at each NCP for each
possible call path within the network would require a prohibitive amount of testing for all networks except
the smallest. Furthermore, private networks are subject to frequent changes. Where a compliance
statement is provided, it shall be supported by computations and transmission performance data for the
apparatus involved (e.g. showing compliance with relevant ETSs).
The limits quoted in this ETS should ensure satisfactory echo and loudness performance.
This ETS does not apply to configurations where a part of the transmission path between the terminal and
the public network contains a segment that incorporates mobile systems or cordless telephones.
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] ETS 300 085 (1990): "Integrated Services Digital Network (ISDN); 3,1 kHz
telephony teleservice; Attachment requirements for handset terminals
(Candidate NET 33)".
[2] CCITT Recommendation G.122 (1988): "Influence of national systems on
stability, talker echo, and listener echo in international connections".
[3] CCITT Recommendation G.131 (1988): "Stability and echo".
3 Definitions, abbreviations and reference configurations
3.1 Definitions
For the purposes of this ETS, the following definitions apply:
Channel, transmission channel: a means of unidirectional transmission of signals between two points.
Circuit, telecommunication circuit: a combination of two transmission channels permitting bidirectional
transmission of signals between two points, to support a single communication.
NOTE 1: In a telecommunication network, the use of the term "circuit" is generally limited to a
telecommunication circuit directly connecting two switching devices or exchanges,
together with associated terminating equipment.
Connection (in telecommunications): a chain of circuits interconnected by switching points, between
two different points in the network.
NOTE 2: A connection is the result of a switching operation.
NOTE 3: A connection which allows an end-to-end communication, e.g. conversation, may be
called a "complete connection".
NOTE 4: A connection makes a communication possible but is not a communication.

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