SIST ETS 300 640 E1:2003

• Abstract:

  To endorse the global standardization (dated) in ITU-T and ISO to give guidance to telephone terminal manufacturers.

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.050.10 - Telephone equipment
• 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 300 640 ed.1 (1996-08) - Human Factors (HF); Assignment of alphabetic letters to digits on standard telephone keypad arrays

Overview

SIST ETS 300 640 E1:2003 is a Slovenian national standard that aligns with the European Telecommunications Standard ETS 300 640. It provides comprehensive guidance on the assignment of alphabetic letters to digits on standard telephone keypad arrays. This standard supports global harmonization by endorsing recommendations from prominent international bodies such as ITU-T and ISO, specifically ITU-T Recommendation E.161 and ISO/IEC 9995-8. Its primary goal is to assist telephone terminal manufacturers in ensuring consistency, usability, and compatibility across both public and private telecommunications networks.

Key Topics

• Letter-to-Digit Assignment
  The standard defines the specific allocation of Latin alphabetic characters (A-Z) to the numeric keys (2-9) on a standard 4x3 telephone keypad array. This harmonized assignment is designed for both hardware keypads (physical buttons) and software keypads (virtual or soft keys).

• Human Factors and Usability
  Emphasis is placed on user-friendly design, including recommendations on legibility, key size, and spacing. The intention is to ensure that adding letters does not compromise the usability or clarity of the keypad.

• Scope and Application
  The standard applies to all telecommunications terminals except those specifically designed for text telephony or those using non-Latin alphabets and diacritical marks.

• Global Standardization
  By conforming to both ITU-T and ISO guidelines, the standard promotes international uniformity in the design and function of telephone keypads, reducing confusion and ensuring interoperability.

Applications

• Telecommunications Equipment Manufacturing
  Manufacturers of fixed and mobile telephones, as well as other terminal devices with dialing functions, use this standard to ensure the consistent layout of keys and correct letter-to-digit assignment.

• Public and Private Networks
  The standard is applicable to devices deployed in both public telecommunications networks (e.g., payphones, PBXs) and private installations (e.g., business telephony systems).

• Software-Based Keypads
  Developers of telephony software and digital communication tools can implement the standard assignment for on-screen or virtual keypads, improving user familiarity and accessibility.

• Enhanced Service Provision
  The common assignment allows service providers to implement features that rely on alphanumeric input (such as phonewords, customer service codes, and directory assistance) without ambiguity or error in user input.

Related Standards

• ITU-T Recommendation E.161
  Global reference for the arrangement of figures, letters, and symbols on telephone keypads.

• ISO/IEC 9995-8
  Covers allocation of alphabetic letters to the keys of numeric keypads for information technology devices.

• ETS 300 511 (GSM 02.30)
  Specifies the man-machine interface (MMI) for GSM mobile stations-including keypad arrangements.

• ETR 116
  Provides human factors guidelines for ISDN terminal equipment, particularly in the areas of character displays and key design.

• ETSI DTR/HF-02009
  Addresses the needs of elderly and disabled users in keypad design.

Practical Value

By implementing SIST ETS 300 640 E1:2003, manufacturers and service providers can:

• Ensure interoperability and user familiarity across devices and services.
• Reduce errors and confusion when using alphanumeric input features, such as SMS or automated service numbers.
• Support the consistent global development and deployment of telephony devices.
• Improve the accessibility and ergonomic quality of telephone keypads for all users.

This standard is essential for those seeking compliance with international norms in telephone equipment design, and for organizations aiming to deliver reliable, user-friendly communication products.

SLOVENSKI STANDARD
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Human Factors (HF); Assignment of alphabetic letters to digits on standard telephone
keypad arrays
Ta slovenski standard je istoveten z: ETS 300 640 Edition 1
ICS:
33.050.10 Telefonska oprema Telephone equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 640
TELECOMMUNICATION August 1996
STANDARD
Source: ETSI TC-HF Reference: DE/HF-01031
ICS: 33.020
Key words: Character, keypad, MMI, terminal
Human Factors (HF);
Assignment of alphabetic letters to digits on standard
telephone keypad arrays
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: [e-mail]
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 1996. All rights reserved.

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ETS 300 640: August 1996
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.

Page 3
ETS 300 640: August 1996
Contents
Foreword .5
Introduction.5
1 Scope .7
2 Normative references.7
3 Definitions, symbols and abbreviations.7
3.1 Definitions .7
3.2 Symbols .7
3.3 Abbreviations .8
4 Assignment of alphabetic letters to digits.8
Annex A (informative): Characteristics of the standard telephone keypad array .9
A.1 Legibility of characters .9
A.2 Size of keys.9
History.10

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ETS 300 640: August 1996
Blank page
Page 5
ETS 300 640: August 1996
Foreword
This European Telecommunication Standard (ETS) has been produced by the Human Factors (HF)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
Transposition dates
Date of adoption of this ETS: 7 June 1996
Date of latest announcement of this ETS (doa): 30 November 1996
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 May 1997
Date of withdrawal of any conflicting National Standard (dow): 31 May 1997
Introduction
This ETS was prepared by TC-HF in response to a request from the 20th ETSI Technical Assembly.
ITU-T and ISO/IEC have adopted an assignment of letters to digits that corresponds to that shown in
figure 1 in clause 4 (See ITU-T Recommendation E.161 [5] and ISO/IEC 9995-8 [4]). In the interests of
maximising global standardisation, ETSI will also adopt this same assignment. This further convergence
of standards should encourage manufacturers to use the standard immediately in the manufacture of
telecommunication terminals using the standard telephone keypad array.
Many existing telephone and other terminals will have assignments of letters to digits that differ from that
specified in this standard. In particular, some assignments exist which conform with national standards to
facilitate text telephony. Before introducing telecommunications services that assume the assignment
specified in the present standard, the consequences of errors arising from the use of non-compliant
terminals should be carefully considered.
For a limited user group, where it is known that all terminals using the service will have the ETSI
assignment of letters to digits, it will be possible to introduce services that use alphabetic input without
further delay.
The standard assignment of letters to digits can also serve as an aide-memoire for individ
...