Standardisation Requirements for
Access to
Digital TV and Interactive Services by
Disabled People
JUNE 2003
TV for All – Standardisation 2
Interim Report to CENELEC
on
TV for All
Prepared by
GERRY STALLARD
STALLARDS CONSULTANCY SERVICES LTD
9 Hookwater Road
Chandlers Ford
Hants
SO53 5PQ
UK
#44 (0)23 802 62291
Email gerry@stallards.f9.co.uk
From the “Mandate to the European Standards Bodies for Standardisation in
the field of information and communications technologies (ICT) for disabled
and elderly people. M/273.”
“The provision of technology-based solutions for integrating disabled and
elderly people and helping them to lead full and independent lives requires
two complementary approaches; the "design for all" approach and the
“assistive technology approach.”
TV for All – Standardisation 3
Contents
Introduction 5
1. Executive Summary 8
2. Progress to date 13
2.1 The Road Map 13
3. Main forms of assistive services on analogue and digital
platforms (terrestrial, cable and satellite) 13
3.1 Assistance on Analogue Platforms 13
3.1.1 Analogue Subtitling 14
3.1.2 Analogue Audio Description 14
3.1.3 Analogue Teletext Screen Reader 14
3.1.4 Analogue Signing 14
3.1.5 Current Availability on Analogue Platforms 14
3.2 Assistance on Digital Platforms 15
3.2.1 Digital Subtitling 15
3.2.2 Digital Audio Description 15
3.2.3 Digital Signing 15
3.2.4 Interactivity 15
4. Transmission and Decoding of Assistive Services 15
4.1 Analogue Subtitling 15
4.2 Digital Subtitling 16
4.3 Audio Description 17
4.3.1 Analogue Audio Description 17
4.3.2 Digital Audio Description 17
4.4 Signing 18
4.4.1. Analogue Signing 18
4.4.2 Digital Signing 19
4.5 Interactivity 20
5. Receiver Terminals, Peripherals and Interactive
Equipment 20
5.1 Receivers and Peripheral Equipment 21
5.1.1 Minimum Performance Standards ` 22
5.1.2 Control functions 22
5.1.3 Connections 22
TV for All – Standardisation 4
5.1.4 External Facilities 22
5.1.5 Upgrades and Future Proofing 23
5.1.6 Interconnections between TV’s, VCR’s,
and PVR’s etc. 23
5.1.7 Decoding abilities 23
5.1.8 Capacity 24
5.1.9 Base line receivers 24
5.1.10 Profiling 24
5.2 Interactive television access 25
5.3 Remote Controls 25
5.3.1 Shape and Size 25
5.3.2 Buttons and Controls 25
5.3.3 Interoperation 27
6. Electronic Programme Guides (EPG’s) and Navigational
Menus 27
7. Production of Assistive Services 28
7.1 Subtitling 29
7.2 Audio Description 29
7.3 Signing 30
8. On-Screen Displays 30
9. Interoperability 31
10. Recording Equipment 31
11. Retention of Recordings 32
12. Promotion of Assistive Services 32
13. Future Developments 33
14. Recommendations 35
15. Recommendations relevant to CENELEC 36
16. Conclusion 37
Glossary of Terms 39
Documentation 41
Organisations providing input to TV for All 43
TV for All – Standardisation 5
Introduction
The EU has set the achievement of gaining “widespread access by all citizens
to new services and applications of the Information Society as one of its major
goals for the coming decade.” There can be no doubt that Digital Television
can play a fundamental role here. Yet to achieve “widespread access by all”
its usability from the outset will need to be based on good design principles.
Failure to do so will result in disabled people, some 20% of European Society,
being excluded from the essential ingredients of information, entertainment,
culture, public discussion and debate.
Today, there are more than 70 million people aged 60 and above in the EU,
representing just under one in five of the population. According to Eurostat1,
over the next fifteen years, the population aged 65 and over will increase by
22%. During this period the number of people aged 80 and over will rise by
almost 50%. Many of these citizens will experience dexterity, cognitive,
hearing and sight problems in later life.
By example, a report by Professor Adrian Davis, from the Institute of Hearing
Research (IHR), indicates that an estimated 81,536,000 adults will have a
hearing loss in Europe as a whole by 2005. By 2015 the figure will be
90,588,0002. This means that more than one in seven adults in Europe will
have hearing problems. Some 7.4 million people who are already suffering
incorrectable sight loss further is set to increase the number of European
citizens experiencing some form of sensory impairment.
If these people are to be attracted to Digital Television then the importance of
assistive services cannot be underestimated. As well as deaf and hard of
hearing people gaining from subtitling there are those learning a second
language or watching a programme in a second language in which they are
not fluent. People with learning disabilities and children starting to read3 also
benefit. Hearing people can find subtitles convenient in their daily lives, for
example, when there is high background noise in their domestic environment.
It follows that by increasing the amount of subtitling on television broadcasters
are providing an improved service for the vast majority of their viewers.
Audio description too can provide a vital service for blind and partially sighted
people. A notable comment by a viewer during the in the AUDETEL trial 4 is
indicative of how people’s lives may be transformed. “Normally after the first
ten minutes of a film I give up. Without the description I wouldn’t have been
able to watch it”.
The availability of sign language can also play an important role, especially on
children’s television for deaf children who are too young to read the subtitles.
1 “The social situation in the European Union 2001 (Eurostat)”.
2 The 81.536 million figure is for people aged 18 and over with bilateral hearing impairment at 25 dB Hearing Level
and above both in EU member states and other European countries (as defined by UN/WHO).
3 See Deborah Lineberger, University of Kansas (2001) “Learning to Read from Television: The Effects of Using
Captions and Narration”, in: Journal of Educational Psychology 2001, Vol.93. No. 2, pg 288-298 and Andrea Shettle,
Gallaudet University (August 1996), “Closed Captions: An Untapped Resource in Combating Illiteracy” taken from
www.robson.org/gary/captioning/shettle.html
4 The AUDETEL project Audience Reaction Final Report 1995 Chapter 5.4.4.2 page 55
TV for All – Standardisation 6
With an increasingly ageing population it is an unfortunate fact that many
people will face problems of dexterity and lose their cognitive powers. Elderly
people, however, must be part of the Information Society; it is therefore
imperative that Digital TV equipment and the basic broadcast services are
easy to use and access.
Europe, in recent years, has seen some encouraging signs towards the
inclusion of disabled people within society. Not least of these has been the
eEurope 2005 Action Plan 5 aiming to accelerate the Information Society and
two important EC Directives: the Framework Directive 2002/21/EC6 and the
Universal Service Directive 2002/22/EC7. Arising from these directives already
a number of initiatives are already in place. In particular one of these was the
Workshop "TV Broadcasting for All" organised by CEN, CENELEC and ETSI
in Seville on 13-14 June 2002. A conclusion of this Workshop was to set up a
Virtual Working Group to look at particular standardisation requirements in
order to further access to Digital TV and interactive services by disabled
people. This interim report under voucher CENELEC/ENTR/e-Europe/2002-
0497 describes to the work of the virtual group to date and outlines the path
towards standardising and identifying users’ requirements.
Indications are that the path towards standardisation may not be easy
because from the initial exchange of thoughts it became clear that the
individual bodies: broadcasters, consumers and manufacturers held differing
views on what may be practicable. Nonetheless at a follow up meeting in
September 2002 at CENELEC headquarters in Brussels it was considered
that by addressing many issues early in the design stage, using Design for
All8 principles, rather than later when production had commenced, then little or
no extra cost might be incurred. It was also recognised that the introduction of
Digital TV offers manufacturers and broadcasters an opportunity to introduce
new products and services and for the consumer to consider how to make
best use of them.
Apart from value to society by addressing such humanitarian issues there are
clear economic benefits to attracting the many millions with disabilities to the
use of Digital TV and Interactivity. Few would disagree with this premise, yet
evidence already exists to show that the process must begin now before the
opportunity is lost. This evidence comes from the UK where over 40% of
households now have access to digital TV9. The same source revealed that
the path to this new technology is not easy for all. A recent report by the UK’s
Independent Television Commission and the Consumers Association, “Easy
TV Report”10, found that when comparing analogue TV to Digital TV some
people perceived it as difficult to use as a Personal Computer. The message
is clear; in the words of the report “the potential benefits that Digital TV can
bring to those sections of society who currently lack access are unlikely to be
realised if Digital TV equipment and services are not easy to use, and
perceived as such. Furthermore, low ease of use – or even perceptions of
5 eEurope Action Plan
6 The Framework Directive 2002/21/EC
7 The Universal Service Directive 2002/22/EC
8 Design for All ICTSB 15.05.2000
9 Independent Television Commission News Release 19/03 published 19/03/2003
10 Independent Television Commission and Consumers Association “Easy TV 2002 Research Report”, 7th January
2003, page 2
TV for All – Standardisation 7
low ease of use, might constitute a significant barrier to the take-up of Digital
TV by some members of the public.” There is no doubt then that as stated in
CEN/CENELEC Guide 6 Guidelines for Standards11 “that standardisation
greatly influences the design of products and services that are of interest to
the consumer and therefore can play an important role in this field”. The
debate now is where standardisation should be applied and to what degree.
To that end the intent of this interim report is to stimulate discussion especially by
broadcasters and manufacturers as to what may be practicable.
11 CEN/CENELEC Guide 6 Guidelines for standards developers to address the needs of older persons and persons
with disabilities Edition 1/January 2002 Section 4.2 page 3
TV for All – Standardisation 8
1. Executive summary
TV for All Group. The TV for All group comprises representatives from a
variety of organisations which have an interest in furthering access to Digital
TV by disabled people. By forming such a group the expectation is that
manufacturers, broadcasters and representatives of disabled audiences can
become involved in a unique exchange of views in identifying what standards
are needed to enable easy access to DTV to the benefit of all. To date input
from delegates to the conference has been limited but it is hoped that this
report will encourage broadcasters and manufacturers in particular to come
forward with comment. This first report therefore details the initial work of the
group towards that end, its progress to date and attempts to identify the main
areas where barriers to access might occur. It is already becoming clear that
while much can be achieved through standardisation the introduction of codes
of best practice and general agreement between providers, producers and
consumers will also bring improvements. Additionally, if many of the elements
noted in this report can be considered within the design stage of DTV
equipment and provision of its services then there is little doubt that society as
a whole will benefit. Overall recommendations towards standardisation and
guidelines are given in Section 15 and those specific to CENELEC in Section
16. A full list of recommendations will be considered and detailed in the final
report.
TV for All Roadmap. In January 2003 a road map was constructed and
placed on the CENELEC website (www.cenelec.org). The intent of this was to
invite comment on all these areas which might become key to standardisation.
Assistive Services. It is generally acknowledged that digital television is able
to improve upon the main forms of assistive services for disabled people:
subtitling, signing and audio description. The shape of that assistance,
however, embraces more than just the provision of services. Learning from
the analogue experience the whole mechanism of Digital TV must become
involved; that is: the transport of services, decoding at the terminal, use of the
terminal itself and the display.
Analogue Assistive Services. While digital television remains in its embryo
stages many people still rely upon analogue services as the main form of
television, even though its limited bandwidth causes some restrictions. Some
of the assistive services mentioned above are available on analogue channels
although in some countries not to the extent that many would wish, even
though the mechanisms for providing them are well established.
Transmission of Assistive Services on Analogue and DTV. A prime
example of such a mechanism is the ITU-R (CCIR) Teletext System B format
which can carry “closed subtitling”. Although generally regarded as a rugged
system, special care is needed to avoid intersymbol interference which can
disrupt subtitling captions. It is recommended that a code of practice is
adopted for aerial installation procedures. Audio description on a separate
sound channel is also possible and now available in some countries. Signing
on analogue however is limited to just a few specialist programmes. Now, with
the development and introduction of DTV, the two former services are more
TV for All – Standardisation 9
easily carried. By example a means of carrying a subtitling service has
evolved through the ETS 300 743 using MPEG2 as described in the DTG 'D
Book'12. The ability of DTV to carry more sound channels eases the path for
audio description especially on satellite channels due the increased
bandwidth. For Digital Terrestrial Television (DTT) services a special form of
audio description carriage has already been developed and tested. Digital
transmission also introduces the possibility of a closed signing service through
the use of Avatars being conveyed at a very low bit rate. Finally there is the
prospect that digital interactivity can become an essential service to house
bound disabled people.
Guidelines for Content Best Practice. Guidelines for the construction of
assistive services already exist in the analogue form and can easily translate
into DTV. The UK’s ITC guidelines for subtitling, signing and audio description
are suggested as a minimum form of best practice together with the views of
such organisations as the FDPDA, RNIB, RNID, Hearing Concern and the
Subtitulado E para personas sordas y personas con discapacidad auditiva
soon to be published.
Central Register of Programmes with Assistive Services. A reduction in
the cost of assistive service production may be achieved through exchanging
programme material that has already been subtitled or audio described in the
main European languages. It is suggested that the European Broadcasting
Union (EBU) or similar organisation acts as a central base for compiling a file
register for use across Europe.
Equipment - ease of use. There can be little progress towards access
without easy use of the equipment to receive these services. The EU report
“Barriers to widespread access to new services and applications….”13 states
that “digital television may ultimately rival the PC/Internet paradigm for access
to Information Society services once digital TV is widely implemented in the
EU”.
If the use of DTV to the community really is to be realised then is imperative
that all receiver functions and facilities together with their remote controls
must be designed with ease of access in mind. By example all control
functions such as switches, knobs, and dials should be clearly labelled. Their
order of importance and their location should be also logical. They should be
user friendly and easy to operate. It is suggested that manufacturers and
service providers included inputs from disabled viewers in the design phases
of new products and services. Standards are needed for common labels and
symbols on receivers and terminals
Receiver Connections. Because the receiver or decoder is no longer
considered as a stand-alone device its connection to peripheral equipment
needs to be simple and include outputs to headphones and etc. Special
attention should be paid to minimising the number of sockets and cables.
Even when simplified these must be clearly marked and accessible. A
12 DTG “D” Book V 3.2 February 2001 section 5
13 EU report “Barriers to widespread access to new services and applications of the information society through open
platforms in digital television and third generation mobile communications. 2003 Section 2.1 page 7.
TV for All – Standardisation 10
suggestion is to collaborate with the UK Digital TV Action Group who are
drawing up guidelines in this area.
Future Proofing. In terms of the receiver market as a whole – it should not
follow the example of the computer industry where year on year older models
are replaced by bigger and better versions. All consumers, and especially
those with less disposable income, would welcome a decoder and receiver
that is “future proofed”. With DTV this may well be achieved through software
down loads or additional devices added to the main equipment using
Common Interface or similar sockets.
Remote Controls. Few if any receivers today operate without the use of a
remote control. Yet it is these devices that come in for most criticism. To be
wholly useful their buttons must conform to some very basic and obvious
considerations such as size, shape, labeling and clarity. The introduction of
tactile indicators should be considered. A fundamental need is that of a single
(programmable/customisable) button giving access to the most commonly
used functions. There can be no better example of this as a basic requisite
than a single subtitling button. The selection of subtitles should be retained
after channel changing. (A suggestion is that button settings of this type ought
to be able to be freely determined i.e. customised by individual users.)
Assistive services once selected should remain selected on channels changes
etc.
Minimum receiver requirements and conformance. The receivers
themselves should have the capability of receiving the main assistive services
and certainly have the option to continue displaying subtitles while other text
or graphics are on screen. It is suggested that a conformance centre for DTV
equipment is established whereby all assistive service decoding and
presentation displays are tested for a minimum compliance. Compliance with
this would allow equipment to display an accreditation at the point of sale,
thus ensuring that consumers are purchasing equipment appropriate to their
needs.
Interoperability. The contentious subject of interoperability was given
considerable treatment in the recent report to CENELEC “Standardisation in
digital interactive television” and its particular reference to MHP”14. It is of vital
importance that any such emerging technology should not move in a direction
that will alienate disabled people wishing to use DTV. As for the purchase of
the decoders, this special but sizeable group of European society should not
need to purchase several set top boxes in order to access services on
different platforms. The representative organisations within the group have
therefore endorsed the need for Open Standards.
Interactive television access
Interactivity via DTV will be important to housebound as such disabled people
should not be disenfranchised from access to these services.
14 Standardisation in digital interactive television Strategy and recommendations for a standardisation policy
supporting the effective implementation of the Framework Directive 2002/21/EC and the establishment of required
interoperability levels in digital interactive television Final version April 2003 Page 5.
TV for All – Standardisation 11
The display of a standard TV screen however is inferior to that of an SVGA
monitor as used with Personal Computers. The resulting “on screen”
presentation therefore can have severe limitations particularly for blind and
partially sighted people. It is recommended that European guidelines are
drawn up to ensure all official websites can be viewed on a television screen.
On-Screen Information. There can be no doubt that for blind and partially
sighted people full access to DTV is dependent on on-screen information. It
follows then that flexible, adaptable interfaces must be available to suit
individual needs. For example all text must be clear and adapt to such simple
factors as size of text and use of colours all placed within a defined “safe”
area. It has been suggested that if digital TV information is to be able to
transfer to other convergent media and screen sizes, then these factors
should be considered during production.
Electronic Program Guides. (EPG’s) and menus are seen as the gateway
to digital services and they too must follow the principle of being logical and
intuitive. A common request is that EPG’s and similar progamme listings such
as “Now and Next” should indicate the presence of subtitling, signing and
audio description. These indications should be either in text form or by a
commonly agreed symbol.
Recording. Currently, due to limitations in the bandwidth used by VHS
VCRs, the recording of teletext subtitling is limited to S-VHS recorders or
through the use of specialist teletext decoding devices. Standard VHS
machines to some degree are able to record DTV but only the channel
selected by the set top box – they have no independent decoding ability.
Digital recorders may enter the market, although current indications that few if
any manufacturers are considering production. Of more importance is likely to
be the Personal Video Recorder (PVR) where use of meta data
accompanying the broadcasts may allow viewers to arrange their own
schedule and set preferences. As with other DTV equipment it is imperative
that the design of DTV recorders and Personal Video Recorders must
incorporate use of assistive services. The technical capabilities made
available by PVR's is certainly promising and it is suggested they should be
investigated for further potential in relation to adapting Digital TV for special
needs.
Promotion of Assistive Services. Evidence exists that while assistive
services may be made available, some sections of the community are either
unaware of them or do not know how to access them. Broadcasters,
representative agencies and National Regulatory Authorities can make
significant contributions here by promoting the availability of services
themselves or by giving encouragement to others. An ideal opportunity
presents itself at the commencement of programmes by displaying
standardised symbols for subtitling and audio description. Programme listings
in magazines and newspapers should be actively encouraged by NRA’s and
similar agencies to use symbols to indicate whether the services are available.
TV for All – Standardisation 12
Future Technology. Finally, with the rapid advancement of technology in
DTV there are encouraging signs that access to assistive services might be
made easier. WGBH-TV Boston has created a National Centre for Accessible
Media, called NCAM. One such NCAM project involves “talking EPG’s for
blind and partially sighted people”15. The progress towards a SAMBITS16
multi-modal receiver is also worth marking. This project aims to develop a
terminal built that will allow individuals with hearing impairment, speech
impairment and/or visual impairment to take full advantage of the broadcasts
on Internet as well as DTV. Input to the report has suggested that Europe
might do well to use the above NCAM example to establish a research centre
of this type based on European needs and digital infrastructure.
15 http://ncam.wgbh.org/convergence/barriers.html
16 http://www.irt.de/sambits/documents/ibc_SAMBITS_overview.pdf
TV for All – Standardisation 13
2. Progress to date
Before considering what form standardisation may take, it was imperative that
the views of the organisations representing disabled people across Europe
were sought. Equally, from the manufacturers standpoint, contributions were
requested of EICTA; and through the EBU the broadcasters were asked to
contribute. To aid this and stimulate an exchange of views between
stakeholders a Road Map was drawn up and in January 2003 placed on the
CENELEC website in an area designated for use by the TV For All group.
Initially access to the website was limited to the participants of the Seville
conference but was widened shortly after to include all interested parties. To
date input to the Working Group is slower than anticipated, although by April
2003 a limited number of contributions were being received. It is hoped that
contributions by manufacturers and broadcasters will be forthcoming and the
distribution of this interim report will lead to discussion at the proposed
meeting in Barcelona on 28 October. A full list of those consulted both in this
interim report and the final will be placed in the annex of the final report.
2.1. The Road Map
An abstract of the road map below includes the basic issues to be taken into
account when addressing user requirements through standardisation
procedures.
i) Identify the main forms of assistance to disabled people that may be
conveyed by broadcast means.
ii) Consider the various ways and means in gaining access to assistive
services.
iii) Consider navigational controls particularly relating to those people with
sensory impairments.
iv) Determine best practice in service presentation techniques for both audio
and visual means
v) Create awareness by National Regulatory Authorities
vi) Create awareness amongst those needing the services and propose
measures for promotion by broadcasters and service providers.
vii) Include proposals for future-proofing
In parallel with this initial work an extensive search was made for any existing
documentation that may relate to DTV accessibility. It became clear that
already a considerable amount of information and initiatives existed both
within Europe and the US. Where relevant these have been considered and
referred to in this report and are listed within the References section.
3. Main forms of assistive services on analogue and digital platforms
(terrestrial, cable and satellite)
3.1. Assistance on Analogue Platforms
Without doubt the mainstay of European broadcasting is still by analogue
means. (This is especially the case for those services using terrestrial and
cable distribution). Where analogue remains a major form of distribution
TV for All – Standardisation 14
consideration should still be given to the basic forms of assistance for sensory
impaired people namely: subtitling, signing and audio description. It is noted
however that these can be limited due mainly to the bandwidth occupied by
the video and audio components of the signal. It is also noted that the extent
of these services has substantial variations between member states.
Contributors to this report have indicated that as a base line all services
currently enjoyed on analogue services must as minimum be available on
DTV.
3.1.1. Analogue Subtitling
“Closed” captions have been derived as a special form of teletext carried in
the Vertical Blanking Interval (VBI), the so-called teletext lines. The style of
the font, its graphics and colours are limited. (Fuller details are given in the
ITU-R (CCIR) Teletext System B issued by the EBU). Improved versions of
teletext have been proposed and adopted in some countries, notably
Germany, but these have not been widespread nor translated into the carriage
of subtitling.
3.1.2. Analogue Audio Description
The bandwidth of analogue services is restricted in that little room can be
found for an additional sound channel. Both France and Germany have
developed a Two-Channel Sound format which utilise one half of the stereo
channels to provide AD. (See section 4.3.1) The UK’s AUDETEL17 trial in the
1990’s used the innovative approach of sending the voice channel within the
VBI. Additionally
3.1.3 Analogue Teletext Screen Reader
Blind and partially sighted people can benefit from a screen reader which can
produce an audio output of teletext pages. The device uses a text to speech
engine but cannot translate graphics such as those used on a weather map.
In the Netherlands a system known as audio subtitling has become a
mainstream service for all foreign language programmes on the three public
TV broadcasting channels. Whilst this is not the same as audio description, in
that subtitles are decoded using text to speech engine and converted into a
synthesised voice, many people value the service.
3.1.4 Analogue Signing
The ability to carry the image of a signing person within an analogue services
is limited unless spare capacity is found for an entirely separate broadcast
channel or a form of a “picture in picture”. Therefore most signing is limited to
“in vision” or open signing on certain programme services. Such services are
usually specifically intended for deaf people.
3.1.5 Current availability on Analogue Platforms
Despite the above limitations some provision of analogue assistive services is
evident across Europe and where available is much appreciated. By example,
at an EBU meeting held in Antalya during 200018 attended by representatives
17 The AUDETEL project Audience Reaction Final Report 1995
18 EBU Teletext Guide APRIL 2000
TV for All – Standardisation 15
from 21 nations, all with one exception stated that they provided at least one
of the three services: subtitling, signing or audio description. The extent of
these provisions however varied in the case of subtitling from a few hours a
week in some countries to other countries whose yearly quotas are set by
National Regulatory Authorities and amounted to over 80% of all programmes.
Some countries are now introducing legislation requiring the provision of such
services, especially on Public Service Broadcasts.
3.2 Assistance on Digital Platforms
Digital platforms, to include terrestrial, satellite, cable and to some extent DSL
make more efficient use of bandwidth. Coupled with the packetisation of data
within the Digital TV MPEG 2 bit streams this allows a variety of services
which are less restricted than hitherto on analogue channels.
3.2.1 Digital Subtitling
Captions may now be varied in terms of the size of font, style and colours.
High quality graphics or icons are available together with a form of
transparency to the background (veiling).
3.2.2 Digital Audio Description
Several separate audio channels are possible, one of which may be used for
a “closed” audio description service (although terrestrial bandwidth limitations
may require a different approach – see below).
3.2.3 Digital Signing
Indications are emerging that a form of “closed” signing may become
practicable either through the transmission of a human figure using low bit
rates or through use of an avatar.
3.2.4 Interactivity
The extent of its usefulness to disabled people may depend on the practicality
of the return channel and its availability. Cable services and proposed return
paths utilising RF offer a higher bit rate than a telephone line, although to date
the perceived wisdom is that the commercial benefits have yet to be realised.
Access to any future services that may develop will be important to sensory
impaired people and must be considered as part of the inclusive design
process.
4. Transmission and Decoding of Assistive Services
4.1 Analogue Subtitling
Transmission. The analogue distribution of subtitles has developed through
the now familiar ITU-R (CCIR) Teletext System B. File transfer between
broadcasters and subtitling companies is mainly by means of the EBU File
Transfer Format 3264 and it is recommended that this practice continue. In
general, carriage of subtitling is achieved by use of line 335 within the Vertical
TV for All – Standardisation 16
Blanking Interval (VBI) and accessed in most countries by a specially
reserved teletext page such as 888.
Page numbering. Other pages are widely used prompting a view that access
to subtitles should be standardised on a specific page number. There are
certain advantages in this where subtitling services cross national boundaries
such as satellite transmissions or in proximity to cross border terrestrial
transmissions. It is recommended that the EBU and service providers
consider this option where appropriate. However, where reception of services
is confined to national boundaries, the expense of modifying data bridges etc
may not have value. Consideration should also be given to the potential
confusion caused to viewers during a changeover period.
Reception problems. Few problems exist in the transmission of analogue
subtitles either by terrestrial, satellite or cable other than those of intersymbol
interference caused by multipath reception. That is to say where characters or
words within the captions are corrupted due to reflections or “ringing”. The
problems are mainly found in terrestrial signals where signals reflected from
trees, large buildings and hillsides are received in addition to the wanted
signals within the incident wave. Similarly cable systems can induce
reflections due to mis-terminations and inward leakage through ineffective
screening. Such corruption causes considerable distress to viewers who often
interpret the problem to be caused by the broadcasters. It is recommended
that aerial installations should follow national good practice as exemplified for
example in the Confederation of Aerial Installer’s Code of Practice for Aerial
Installation19 (to include CENELEC 50083 all parts). It is also recommended
that broadcasters and organisations representing deaf and hard of hearing
people jointly provide information on how to recognise these problems and
their resolution.
4.2 Digital Subtitling
DVB format. The distribution of subtitling by digital means has clear
advantages not least in its resilience to interference. Clearly the extent of its
use is currently limited by those countries adopting digital services. With
national regulation requiring the provision of subtitling on digital terrestrial
television (DTT) broadcasts, the UK has produced a draft format now known
as DVB Subtitling Systems ETS 300 743 V1.2.1 (2002-04)20. With its proven
track record and incorporation into DTT decoders and idTVs (integrated digital
TV’s) it is recommended that this be adopted as a standard.
Authoring. To date subtitling is still authored in analogue form and if required
could be mapped to DVB subtitles using the “VBI Subtitle Mapping to DVB
Subtitles V.1” as drafted by the UK Digital Television Group. Mapping
incoming analogue subtitles to the digital format as used by digital cable
companies is also required. Further versions of this report will contain
19 Confederation of Aerial Installer’s Code of Practice for the Installation of Aerials and Receiving Equipment in the
Domestic Environment 1998
20 Final draft ETSI EN 300 743 V1.2.1 (2002-06) European Standard (Telecommunications series) Digital Video
Broadcasting (DVB); Subtitling systems
TV for All – Standardisation 17
reference to methods used and whether there is a recognised approach that
can lead to standardisation.
4.3 Audio Description
Pre and Locally Mixed Formats. To achieve audio description the narrative
needs to be overlaid on the normal stereo programme sound. This can be
done in one of two ways:
i. Pre mixed. Prior to transmission the AD is pre mixed with the stereo
main programme sound. The resulting composite channel is then
transmitted as another full-bandwidth audio channel.
ii. Locally mixed. Audio description is broadcast as a mono audio
channel and added to the stereo programme sound in the receiver
(or head end). By adding fade and pan control information to the
mixing process the juncture between main sound and the
descriptive passage is made less abrupt and placed under the
control of the listener. The pre-mix technique is suitable where the
available bit rate permits the transmission of an additional stereo
sound channel.
4.3.1 Analogue Audio Description
AUDETEL Project. Probably the most noteworthy form of analogue TV audio
description trial within Europe was the abovementioned AUDETEL project
undertaken by the ITC supported by EC funding. The UK trials, 1994 -1995,
using the locally mixed format, were relatively successful but there remained
some concerns about the speech quality unless two or more VBI lines were
used. As the end of the project coincided with the planning for Digital
Television agreement reached between the RNIB and the broadcasters was
that any such service would be more suited to digital transmissions which
were being anticipated at the time. (Unfortunately the anticipated early
adoption did not prove possible after all.) It is noted that the report “Design for
All, Annexe B, Recommendations for Digital Broadcasting”21 refers to
AUDETEL becoming a European wide standard. It is suggested that in the
light of progress with digital audio description this should be deleted
Other Analogue AD Formats. Some EU broadcasters currently provide premixed
analogue Audio Description particularly in Germany and France
including ZDF, Bayerische Rundfunk and Arte. Viewers using cable or
terrestrial services may opt to select the AD dialogue with main sound or just
the main sound channel. To date analogue satellite viewers are
disadvantaged in that no such option is available, instead the two channels
are be separated and heard in mono. These services utilise one half of the
stereo channels to provide AD and use the pre-mixed technique described
above. In the US where the video and audio consume less of the given
bandwidth, use is made of the Subsidiary Audio Program (SAP).
4.3.2 Digital Audio Description
Use of MPEG 2. For satellite channels with less bandwidth constraints it is
relatively easy to carry an additional sound channel. Some stations in
21 Design for All ICTSB 15.05.2000 Annexe B page 20
TV for All – Standardisation 18
Germany and BSkyB in the UK are already supplying such a premixed
service. DTT services however have a more limited bandwidth and as such
the UK broadcasters adopted a different approach. This was to place the
audio description channel as packets within the standard MPEG 2 bit stream.
A full description is given in the DTG D-book v3.2 Chapter 4 (Audio System
Characteristics)22. The technique includes coded fade and pan control
information in the PES_private_data of the SI. The signalling rate is typically a
few bytes per second. The receivers then make use of the pan and fade data
to locally mix the mono audio description with the normal stereo programme
sound channel.
The above technique could in the future potentially be used for other
broadcast and non-broadcast services but is not intended to replace the use
of pre-mix audio description where platforms support the bandwidth needed.
Recently the ITC has asked the DVB Commercial Module to endorse the
above as an editorial activity to be added as an informative annex to the DVB
Implementation Guidelines (TR 101 154). It is recommenced that ETSI accept
this as an optional standard.
Audio Description Module. During the above development The Digital
Network in the UK in conjunction with the RNIB undertook work on a decoder
known as Audio Description Module (ADM). Based on many of the principles
of the former AUDETEL decoder this was designed to fit in a PCMCIA or a
Common Interface slot (CI) of Set Top Boxes (STB). While a limited number
of prototypes became available during 2002 the necessary funding to produce
a large-scale order has yet to become available.
Progress towards the integrated decoding transmission and decoding of AD
can be made if the next generation of silicon fulfils the necessary
requirements. Current indications are that MPEG 4 may be a suitable vehicle
for AD. Also the SAMBITS (IST-1999-1205) project using MPEG 2, 4 and 7
may provide an audio channel capable of conveying audio description. It is
recommended that CENELEC and ETSI closely monitor these developments
before giving consideration to any standardisation.
4.4 Signing
4.4.1 Analogue Signing
Across Europe open signing has been available for some time but, as with
open subtitling, conflicts can arise with viewing by the wider audience.
Specialist programmes aimed at sign language users are also available in
some countries but with the criticism that the programmes are broadcast in
unsocial times of the day. Clearly it is possible to provide a dedicated channel
for deaf people who need or use signing either in analogue or digital form, but
it would need considerable support. One such channel in France, TVST,
commenced in November 2002 carrying subtitled material but clearly it could
have open signing.
22DTG D-book v3.2 Chapter 4. (Audio System Characteristics). 1996-2002
TV for All – Standardisation 19
4.4.2 Digital Signing
Low bit rate channels The option of closed signing in a compressed digital
form has been considered in Germany and the UK. In order to convey closed
signing within a separate channel the level of definition required is dictated by
the resolution of the image; this should be sufficient enough to show all lip,
face and hand movements. Current indications are that a bit rate to convey
such images is around 300 kbit/s although some UK research (notable by the
BBC and ITV Laboratories) indicates that lower rates may be possible. To
date it is understood that there are no plans to introduce this form of service at
these bit rates.
Use of Avatars. Currently a number of research projects are investigating the
use of signing avatars for various applications and especially relevant here is
the possibility of closed signing in television programmes. Other applications
include: teaching reading to deaf children, developing sign dictionaries and
siting within information kiosks and shops such as post offices.
A notable avatar project was VisiCast (http://www.visicast.co.uk). In An EU
funded project (2000-2002) the long-term objective was to have automatic
translation of teletext subtitles into animated sign language. The project
demonstrated that virtual human characters could convey usable signing for
television, point of sale and Internet applications. In view of this, the VisiCast
project has implemented a simplified 'closed signing' system, where the image
of the sign language interpreter can be turned on and off by the viewer. The
advantage of the 'virtual human' signing approach is that only the positioning
information required to activate the avatar in the receiver (face, body, hands)
need to be transmitted, reducing the required bandwidth by up to a factor of
ten compared with a video approach ( about 30kbit/s). More significantly such
an approach promises to open up all programmes that have been subtitled.
into sign language gestures and movements. Techniques to translate in realtime,
however, from English into natural forms of signing ended in December
2002. VisiCast has since been replaced by eSIGN. This is still investigating
avatar technology, but the application is aimed at the Internet. The project is
within the eContent project, funded by the EU, with partners in Germany, the
Netherlands and the UK who will be providing eGovernment information in online
sign language using avatars.
It is understood that BBC Research and Development has developed its first
demonstrator for broadcast closed signing based on motion capture and is
planning to continue this work.
Developments in Germany. In parallel with the above initiatives the German
Workgroup "Subtitling and Sign-Language" (Arbeitsgruppe Untertitel und
Gebärdensprachdolmetschereinblendung") are to ask the Institut für
Rundfunktechnik (IRT) to conduct research into what elements of MHP are
needed to implement DVB carriage of a signing interpreter without the use of
an Avatar.
The following characteristics are to be investigated:
- The ability to alter the width and height of the inlay
- Select the inlay’s position on screen
TV for All – Standardisation 20
- Provide options to change the background from transparency through
to black and within an oval or rectangular window
- Obtain the data to form the interpreter either from a DVB bit stream or
the Internet
- Consider any bandwidth reduction by use of new technologies such as
DIVX-5 etc.
-
As with developments in the field of Audio Description it is recommended that
standardisation organisations closely monitor prospects of closed signing
mechanisms.
4.5 Interactivity
Generic APIs. Future access to interactivity through a common standard is no
less important to disabled people than to their fellow citizens. Indeed it may be
argued that ease of access is more important in that it can offer market
services that may otherwise be difficult to visit in person. Yet it is noted from
the report by Contest Consultancy to CENELEC on 12 March 2003
“Standardisation in digital interactive television”23 that to date there has been
no consensus across industry towards a generic API platform and several
forms of API exist in the European market. Interoperability between platforms
is clearly an issue here and many look to the EC and standardisation bodies
to provide a migratory path to a common standard.
MHP. Reference to interoperability in the context of the Frame Work
Directive24, the Design for All Final Report 15.05.0025 and statements in the
meeting held at CENELEC on 12 March 2003 indicate that MHP is still the
favoured execution engine. While this is understood by representative
organisations for disabled people the view is, especially in the more mature
UK Digital TV market, that earlier API’s such as MHEG5 should migrate to, or
co exist with MHP. This would ensure that disabled people are not denied
access to new services. It is noted that such processes involve the
CENELEC/EBU/ETSI Joint Technical Committee, DVB and ATSCC and they
hope to resolve these issues within a short time frame.
5. Receiver Terminals, Peripherals and Interactive Equipment
For the foreseeable future the television receiver with its display screen and
associated audio outputs will remain the prime device for access to digital
television, whether as a standalone device, such as an idTV, or by connection
to peripheral equipment such as decoders, set top boxes and Personal Video
Recorders (PVR’s). With very few exceptions today these are controlled by
external devices: remote controls, keyboards and the mouse.
Studies into access needs. In recent years there have been a considerable
number of studies into the means of use and access. It is the intention of this
23 Standardisation in digital interactive television Strategy and recommendations for a standardisation policy
supporting the effective implementation of the Framework Directive 2002/21/EC and the establishment of required
interoperability levels in digital interactive television Final version April 2003 Page 5
24 EC Framework Directive 2002/21/EC March 2002 Articles 17 and 18
25 Design for All ICTSB 15.05.2000 Annexe B Section B1page 20
TV for All – Standardisation 21
report to consider these and address the more practicable aspects for
standardisation. Due acknowledgement is given to the most notable of these
reports which are:
Information and Communications Technologies ICT Standards Board26
CPB/WGBH Access to Convergent Media Barriers to Convergent 27
ITC and Consumer Association’s Easy TV study28
ANEC Consumer Requirements in Standardisation relating to the Information
Society 29
These studies have in part or in entirety looked at the display terminals, the
displayed content, means of control and access and the interconnections.
This section will concentrate on receiver terminals and peripheral equipment,
their controls and connections.
5.1. Receivers and Peripheral Equipment
Basic Design Principles. The range of facilities now provided by receivers can
be considerable; the downside however is that in turn these can lead to a
proliferation of control switches and connections. For even the most
competent person their functionality can cause bewilderment. This
observation, endorsed by several reports, suggests that encouragement is
needed for digital television equipment manufacturers and service operators
to place an increasing level of importance in making the equipment and
services user friendly and easier to use. Considerable progress towards
realising this would be achieved if manufacturers and service providers
included inputs from disabled viewers in the design phases of new products
and services.
Benefits of Good Design Principles. The CEN/CENELEC Guide 6 “Guidelines
for standards developers to address the needs of older persons and persons
with disabilities” 30and Design for All - ICTSB Project Team 31 are very
relevant here. There is no doubt that the design factors which aid people with
sensory and cognitive impairments also improve usage by more able
consumers. While it might be argued that considerations may have cost
penalties these can be offset if addressed early in the design stage and
applied across the entire range rather than in a few specialised top of the
range devices. The spin off for the manufacturer is that the product appeals to
a wider consumer base. While this is an ideal concept, it can only succeed if a
product’s functions are easily understood and known by the consumer.
26 Communications Technologies ICT Standards Board 1999 Design for All Final Report
27 CPB/WGBH Access to Convergent Media Barriers to Convergent Media for Individuals Who are Blind or Have Low
Vision
28 Independent Television Commission (ITC), Consumers’ Association (CA) and Design Council (DC Easy TV 2002
Research Report April 2002 the Independent Television Commission (ITC), Consumers’ Association (CA) and Design
Council (DC
29 ANEC Consumer Requirements in Standardisation relating to the Information Society January 2003
(ANEC2003/ICT/008)
30 CEN/CENELEC Guide 6 “Guidelines for standards developers to address the needs of older persons and persons
with disabilities” Edition 1 January 200219. Report on Standardisation in Digital Interactive Television by Contest
Consultancy 4.1 v page 24
31 Design for All - ICTSB Project Team Final Background Report 15.05.00
TV for All – Standardisation 22
5.1.1 Minimum Performance Standards
Minimum Baseline Conformance. With the main forms of assistive services
being available on analogue services for many years it is not unreasonable for
consumers to expect them to be available on all DTV equipment. It is
therefore recommended that standardisation organisations consider the
establishment of a conformance centre which would undertake testing
decoders to ensure that they provide the necessary minimum functions
allowing accessibility. Receivers that pass the minimum base line functions
could carry a list of ”accessibility standards” which are readily identified at the
point of sale. In addition it is recommended that an easily recognisable symbol
is devised that could be used on a label or “swing ticket” to indicate that they
fulfill the minimum standards of easy access and use of control functions.
5.1.2 Control functions.
All control functions and facilities including switches, knobs, and dials should
be clearly labelled with serif typefaces, uniformly spaced and placed in a
logical fashion. The importance and location of controls should be identified by
their size (also texture or shape) the most important being larger. All control
buttons etc with accompanying labels should have a line to show association.
The line should be kept away from any lettering especially if it is raised to
avoid tactile confusion with the lettering.
Where the above are placed behind a panel this should be made obvious to
the user and marked with tactile surface indicators. It is recommended that, in
conjunction with representatives of sight impaired people, an industry
standard is devised in this area.
5.1.3 Connections
Sockets and Connectors. External connections to peripheral devices should
be easily accessible, defined by size and clearly marked. Again, if behind a
panel, this should be clearly marked with tactile indicators. To enable
connection to VCR’s, set top boxes, DVD's and PVR’s the very minimum of
two SCART connectors is now a basic requisite. An audio jack socket for
headphones and connection to audio loops for use with hearing aids is also
fundamental for deaf and hard of people and should be mandated. An RF
loop-through is desirable for connection to recording devices. The facility to
connect video cameras, hi fi and other AV devices is now commonplace and
should be provided again with clear markings. All services should be available
via external ports to facilitate devices such as voice synthesisers and Braille
printer using an industry standard e.g. XHTML.
Standardised cables and connectors should be used rather than proprietary
versions. All should be marked with common and easily understandable
symbols with clear information given in the accompanying manual. Any
symbols used must have been tested through consumer clinics.
5.1.4 External Facilities
The unit should indicate that a remote control button has been depressed; by
example for example by the illumination of an LED.
TV for All – Standardisation 23
Speech commands through a microphone are beginning to make an
appearance within PC systems and should be considered for use within
idTVs.
Audio information is especially helpful to blind and partially sighted and elderly
people with dexterity problems. The following facilities if built in to receivers
would be of considerable benefit:
- The option of auditory tone and visual clues to indicate incoming
information and processing. Each manufacturer could offer this facility
as part of the range.
- The ability to repeat any audio messages.
- An option for essential keys or buttons to “speak” when pressed should
be available.
5.1.5 Upgrades and Future Proofing
Confidence in digital services and especially the receivers as a long term
investment would be considerably enhanced if terminals could incorporate
backward compatibility and “future proofing” either by means of software down
loads or simple addition of hardware. While it is noted that idTV’s are required
to incorporate a Common Interface (CI) slot, consideration should also given
to including them within Set Top Boxes thus extending their useful life in the
event of new developments. This view is endorsed by the Report on
Standardisation in Digital Interactive Television by Contest Consultancy32
where it is stated standards have to be sufficiently future proof, i.e. it must be
reasonably certain that they do not have to be exchanged half-way through
the implementation process because they are technically or economically
overtaken.”
5.1.6 Interconnections between TV’s, VCR’s, and PVR’s etc.
All receiving terminals such as set top boxes will need to be linked to other
devices, for example the analogue TV, VCRs and soon PVR’s. The
interconnection of these devices is already too complex for many consumers and
especially those who are disabled. Consideration must be given to simplifying
these interconnections. The UK Digital Television Group has been working in this
area for some time and has produced Connectivity Guidelines for Installers and
Manufacturers. It is suggested that contact is made with the DTG to look at a joint
form of standardisation. The guidelines relate to best practice for connecting
digital converters and other devices to TVs and VCRs. For example there would
be a value in colour coding SCART cables. Some forms of SCART connectors
are prone to disconnection when moved thus causing a variety of problems. The
design of the connector and its socket should be improved to avoid this.
5.1.7 Decoding abilities
The most basic receiver must include ability to decode subtitling and audio
description services. This much is already recognised in the US where
currently the Federal Communications Commission (FCC)33 are looking at
ways to require all DTV’s to include a caption decoder. This may allow the
32 . Report on Standardisation in Digital Interactive Television by Contest Consultancy 4.1 v page 24
33 http://www.fcc.gov/Bureaus/Engineering_Technology/News_Releases/1999/nret9001.html
TV for All – Standardisation 24
viewer to control the caption display by selecting key features such as
different fonts, character sizes and colours.
Minimum decoding functions and Conformance to EC Standards. It is
understood that virtually all UK DTV receivers have the capability to decode
subtitling although some cheaper models are now coming to market which do
not have this facility. Within the wider Europe the same pattern may emerge.
To ensure full access for hearing impaired users there is a clear argument that
through standardisation all decoders sold in the EC must be able to decode
subtitling. The same applies to audio description, where the cost of
introducing the AD decoder in all receivers would be offset by economies in
large-scale production. The ability of DVB decoders to provide these facilities
must be clearly indicated at the point of sale. As above it is recommended,
perhaps in conjunction with the DVB board, that standardisation organisations
draw up and then promote an easily recognisable symbol that indicates
compliance with these minimum functions.
5.1.8 Capacity
It is noted that many set top boxes appearing on the market do not have the
processing capacity to carry captioning or subtitling services within the
graphics plane alongside EPG’s, interactive services and other on-screen
graphics. Such restrictions clearly disadvantage sensory impaired users. All
receiving equipment therefore should as an option be capable of displaying
captioning and subtitling services alongside other textual services. As
separate signing streams develop these too should include this requirement
for part of a manufacturer’s range. The ability to perform these functions
should be included in the recommended basic standards for a receiver
terminal.
5.1.9 Base-line Receivers
Agreement at a meeting held at CENELEC on 12 March 2003 was that
CENELEC/EBU/ETSI Joint Technical Committee and EICTA will work towards
a base line receiver. It is also noted that the UK Government’s Digital Action
Group are working on a baseline receiver. It is therefore imperative that any
ongoing work should be co-coordinated to ensure that the needs of disabled
people are included from the outset.
5.1.10 Profiling
The Design for All – Executive Summary Report34 refers to the possibility of
terminals storing different profiles for those family members who have
different needs. For example people who need background colours to give
good contrast or different volume control settings. The unit could also provide
automatic selection of subtitling or audio description. It is noted that within the
above Design for All, Standard CEN TC 224 WG 6 that profiling was to be
considered as Medium priority in Q3/2000 and this should be pursued.
34 Design for All ICTSB 15.05.2000 Annexe B page 20
TV for All – Standardisation 25
5.2 Interactive television access
Interactivity is considered by some as a major method of interaction between
the public and public offices, to include government. It is essential therefore
that disabled people should not be disenfranchised from access to these
services.
PC displays vs. TV screens. Take up to date has however been limited with
more reliance on the Personal Computer rather than through use of a
television and a set top box. In some part this may be due to the display of the
television screen when compared to that of an SVGA monitor where the TV’s
resolution relies on interlace and a more limited line structure. The resulting
“on screen” presentation can have severe limitations for particularly blind and
partially sighted people. It is recommended that standardisation organisations
draw up European guidelines similar in manner to the US for example: Web
Content Accessibility 35 The guidelines should include particular note that all
official websites must adhere to the minimum principle that the content may
be viewed on a television screen with its display limitations when compared to
the SVGA screen of a PC.
5.3 Remote Controls
Regarded as the essential tool for access to television it is probably the most
criticised by the viewing audience. While some manufacturers have made
great efforts in designing an attractive yet useable device there are still many
units which confuse by their appearance alone. It is appreciated that there is a
wish to “badge” a receiver’s remote control thus identifying the manufacturer’s
product. Nonetheless there is also a strong argument for some form of
uniformity especially in the layout of buttons, their size and labeling. A major
criticism is often voiced about the number of buttons on the face of the control
unit particularly amongst the lower priced TV receivers. A number of recent
reports has drawn attention to remote controls, details of the reports are found
in the Reference Section. The following is drawn from these reports with
additions.
5.3.1 Shape and size
The unit should be comfortable to hold and be useable by either hand. It
should not be miniaturised to the point of while looking attractive it becomes
unusable by less dexterous people. The construction of the body should be of
non-slippery surface.
5.3.2 Buttons and controls
Unit Design. Only the minimum number of functions should be on the “face” of
the unit. Secondary controls should be placed under a cover which should be
easy to open. While retaining the individuality of units it should be possible to
arrive at a common layout. For the most commonly used functions some
convention is beginning to appear. By example placing the “off” and mute
buttons at the top followed by the four coloured buttons. The buttons should
be arranged in the conventional fashion of red, green yellow and blue. The
35 Web Content Accessibility Guidelines 1.0 W3C Recommendation 5-May-1999 (http://www.w3.org/TR/WAIWEBCONTENT/).
TV for All – Standardisation 26
central area should have a larger circular select button surrounded by arrows
denoting up, down and sideways.
Buttons. Buttons should not be too small, wrongly shaped and narrowly
spaced. They should be operated independently avoiding “double key”
pressing.
They should be easily seen against the background, especially in terms of
colour and contrast. The symbols or labels should not rub off. There is a clear
opportunity here for a standard set of terms and symbols.
All buttons should incorporate a “positive” feel when sufficiently depressed.
Essential buttons should be of different size and shape thus providing and an
intuitive “feel”.
The main TV or set top box should indicate that a button has been depressed;
for example by the illumination of an LED.
Confusion with complex menu paths would be eased by the introduction of an
“Exit” or “Return to start” button. The terminology or symbol used however
needs to be standardised.
It might be particularly helpful for those with dexterity problems or sight
impairment if an “all in one” remote control became available that had similar
buttons and controls as the “Big Button” telephone. Further consideration to
this suggestion should be made in collaboration with organisations
representing blind and sight impaired people such as the European Blind
Union.
Direct Access. Commonly used services should be accessed by a single
button and one plea often repeated by hearing impaired people is the need for
a direct button to subtitles so that when subtitles are selected channels may
be changed and subtitles will always appear.
Tactile Indicators. Tactile indications should incorporate ES 201 384 (1998-
12) “Human Factors Telecommunication keypads and key boards-tactile
identifiers”. Convex and concave buttons may also help some users. Further
communication is recommended with the European Blind Union and similar
bodies to determine whether additional recommendations are needed for TV
remote controls.
Intra red transmission. Infirm people and those with dexterity problems would
welcome remote controls whose infrared transmission links work from any
angle.
Location indicator. A common difficulty experienced by many people not least
for blind and partially sighted users is locating the controller after use. Many
DECT telephone hand sets incorporate a button on the base station that
initiates an audible alarm on the handset. It is recommend that this practice be
extended to remote controls.
TV for All – Standardisation 27
5.3.3 Interoperation
All-in-One. With the proliferation of “black boxes” in the home, each with its
own remote control (TV receiver, VCR, DVD, Set top box, Hi Fi) serious
consideration must be given to remote controls that could interoperate with
other devices. The advantages are clear: for example a single control for
commonly used functions such as channel change and volume control. The
familiarity of one controller brings ease of use. Already some manufacturers
such as BSkyB in the UK provide a controller which operates the TV as well
as the set top box.
Remote control code conflicts. A further confusion caused by some controllers
is exacerbated where the codes conflict with other controllers. Standardisation or
at the least some form of registration would resolve this area of confusion.
6. Electronic Programme Guides (EPG's) and navigational menus.
Digital television is able to offer an array of services far beyond the limited
number of channels in the analogue era. While it is still possible to “zap”
through the channels to see what is available at that time the task of planning
beyond the next hour on some platforms is practically impossible. With the
proliferation of themed channels the advent of PVR’s and Video On Demand
the traditional one stop form of ”scheduled broadcasting” may find less favour
with viewers. Because of this programme guides in electronic form, either
through an EPG or a navigational mechanism have become a necessity.
Indeed without their use certain services may no longer be accessible.
Research by NOP/World in 200345 however shows that many people,
particularly the elderly, do not know how to access analogue subtitles on their
televisions. This problem will be exacerbated as consumers are faced with
increasingly complex Electronic Programme Guides and a range of interactive
services.
EPG Construction and Display. In general the EPG’s are likely to be provided
by the broadcasters themselves or in the case of Navigational Mechanisms
generated in the receiver derived from meta data provided by the
broadcasters. The form of presentation can be a simple “Now and Next”
format to a full progamme and service menu detailing information for that day
and beyond. It is essential therefore that certain safeguards are built into
these forms of guidance:
- All information that is visually displayed, such as EPG, interactive
menus for pay per view etc, should be available electronically at an
external connection point (standard or special port) to facilitate the use
of special assistive devices (e.g., voice synthesizers, Braille printers).
The information should be available in an industry standard format.
- Where there is access to additional services (e.g. automatic VCR or
PVR programming), then a standardised interconnections and data
protocol should be used between all the component parts that use
these services.
TV for All – Standardisation 28
- The presentation of text and graphics should follow the principles set
out in the On Screen Graphics Section 8.
- All information should be intuitive and logical. Menu structures should
be simple each following a similar pattern path. It is recommended that
a standard set of commands is derived for basic navigation tasks.
- Commands given by the remote control should follow an obvious
pattern using a minimum number of keys and keystrokes. (Compliant
with the ‘General Consumer Principles for Standardisation relating to
the Information Society’36
- In conjunction with the remote control there should be single button that
returns the viewer to the opening menu.
- Any index should be easy to use and any programme classification
system should be easy to understand and unambiguous.
- Essential services such as subtitling or audio description must not be
buried within menus making them difficult to access. Once the service
has been selected it should become available from “switch on” and
“channel change” unless turned off by a dedicated toggle on the remote
control.
- All programme information relating to services carrying subtitling, audio
description or signing must indicate this either in the text or a
commonly recognised symbol. It is recommended that standardisation
organisations devise a symbol for each of these three provisions. It is
noted that the Design for All Executive Summary 37 recommended
developing standard symbols for marking way-finding technology under
SO SC 35. ITU-T E.121. Reference may also be made to the following
ITU guidelines:
- Pictograms, symbols and icons to assist users of the telephone
service. ITU-T F.902 (02/95), Interactive services design guidelines.
ITU-T F.910 (02/95) – Procedures for designing, evaluating and
selecting symbols, pictograms and icons.
- The provision of additional information should be in a standard metatag
form that is compatible between Electronic Programme Guides and
other programme indexing recording or logging systems;
- Terminology must be limited to easily understandable terminology
rather than proprietary terms which may cause confusion.
- Seldom used commands or information should be hidden
- Viewers should be able to customise screen displays, for example to
make the text large or change the colours and contrast
- Interactive menus on the screen should use direct selection techniques
where practical.
7. Production of Assistive Services
The common forms of assistive services for sensory impaired people are
subtitling, audio description and signing with the former having been provided
in some countries for over 30 years either in open or closed form. To date few
36 As related in ANEC2003/ICT/008 January 2003 5.2 DIGITAL BROADCASTING AND RECEPTION page 18
37 Design for All Executive Summary 15 may 2000 GEN 18 page 14 (07/96
TV for All – Standardisation 29
codes of practice or guidelines exist although some are now beginning to
emerge; for example Subtitulado para personas sordas y personas con
discapacidad auditiva.38 Subtitulado a través del teletexto (PNE 153010)
soon to be published and http://www.joeclark.org/access/description/
During the Seville Workshop the EBU agreed to provide a resume of best
practice for subtitling. It has been agreed that these will be compiled in time
for the final report due in November. However in the meantime as a basis the
following guidelines are drawn from recommendations by the FDPEDA39 and
the ITC40 .which are of a form generally accepted as minimum production
standards.
7.1 Subtitling
Minimum Guidelines and Best Practice. Reduce viewer’s frustration by:
- Providing subtitles as near synchronous to speech as is practicable
- Allowing adequate reading time
- Reflecting the spoken word with the same meaning and complexity
without censoring.
- Constructing subtitles to contain all obvious speech and sound effects
- Taking care with shot changes
- Constructing subtitles which contain easily read sentences and
commonly used sentences in a tidy and sensible format
- Placing subtitles in time and place
- Giving particular regard to the intended audience e.g. to include
children.
- Giving good contrast between foreground and background colours
- Using Tiresias as the digital subtitle font or good equivalent.
- Using text height of 24lines high on the capital letter Y.
7.2 Audio description
Minimum Guidelines and Best Practice. These have been derived from
recommendations by the Royal National Institute of the Blind (RNIB) and from
the above ITC Guidelines as follows:
- the description should provide key information, e.g. who, where, when,
what
- the description should be in the present tense
- the description should not intrude into the dialogue
- the music and effects should be used to enhance the description, as well
as the original dialogue
- omit the use of unnecessary personal pronouns – e.g. “Now we see…”
38 Subtitulado para personas sordas y personas con discapacidad auditiva Subtitulado a través del teletexto (PNE
153010)
39 European Federation of Parents of Hearing Impaired Children (FEPEDA) Policy on Television Broadcasting for
Deaf and Hearing Impaired Children Draft 2 24/05/99
40 http://www.itc.org.uk/itc_publications/codes_guidance/index.asp
TV for All – Standardisation 30
- describers should not voice a personal opinion or interpret events. The
description is there to clarify what is going on
- do not state the obvious
- for clarification use pronouns and place names.
7.3 Signing
Minimum Guidelines and Best Practice. To date there would appear to be little
advisory information about the sign language interpretation for television.
However the following ITC guidelines were derived following extensive
discussions with the UK deaf organizations and experts in the field of signing.
- The interpreter should occupy at least one sixth of the screen.
- Appropriate clothing should be worn to ensure good contrast and that the
interpreter’s hands are visible.
- The interpreter should be of sufficient size and resolution to show all
movements of the full upper trunk together with arms, hands and fingers,
shoulder, neck and all relevant facial movements and expressions. The
important component of lip speaking must also be discernable.
- Gestures that convey meaning through sign language must be easily and
accurately recognised.
8. On Screen Displays
As indicated in Section 5.2 television screens do not have the resolution of a
PC monitor. As such severe limitations are placed on viewing textual
information particularly for blind and partially sighted. When designing on
screen text and graphics the following should be borne in mind.
- The optimum viewing distance from a TV screen is typically about 5 to
6H (where H = height of the screen) although most people sit further
away than this distance.
- All text should be within the defined 'safe area’ which is nominally 80%
of a 14:9 screen.
- All text to be sans serif typeface of the Tiresias form and at 24-point
minimum.
- Light text on a dark background is easier to read on a TV screen.
- Use simple screen layouts, or provide the user with the option to look at
one thing at a time.
- Whatever form of presentation engine and receiver is employed there
must be sufficient capacity to allow display subtitling coincident with
other textual information.
- Further information can be gained from the RNIB (www.rnib.org.uk)
TV for All – Standardisation 31
9. Interoperability
It is noted from the report to CENELEC, Standardisation in Digital Interactive
Television41, “that the lack of interoperability on the software level, and the
hampering development of open, horizontal markets for interactive content
and digital interactive receivers in Europe, are considered by many to be the
key issues”.
Recent pronouncements by the EC42 have referred to Article17 of the
Framework Directive. These have indicated that unless the objectives of the
Article are not reached through implementation at a Member State level by
July 2004 it can decide to make the relevant standards and specifications
compulsory. These comments have however attracted some criticism.
Multiple Boxes. For the disabled consumer and especially those with limited
disposable income there are particular implications here. Little is to be gained
if access to all platforms can only be gained through multiple set top boxes.
Yet as many of their design principles are being based on the MPEG2
architecture a relatively simple modification should allow, say, a terrestrial set
top box to decode both satellite and cable services as well. Many consumers
would find it hard to find any other widely used product to be so restrictive.
Further, where conditional access system (CA) is used, all equipment should
allow modifications to the proprietary CA, thus providing Open Standards.
Interoperability of digital TV equipment, whatever platform, should also extend
the provision of adequate capacity to allow carriage of both interactivity and
subtitling/signing and /audio description.
As a step towards these aims many argue that support should be given to the
Multimedia Home Platform (MHP) and its ability to work alongside such
existing engines such as MHEG5.
10. Recording Equipment
Analogue VCR’s. By far the most common medium for recording is still the
VCR in its VHS form. While for most viewers this format has proven to be
highly successful, due to the lower bandwidth used it cannot record the
analogue teletext form of subtitles. Versions of the S-VHS format are to some
degree able to do so but interchangeability of tapes between different makes
of recorders is not always successful. Some manufacturers produced
specially adapted VCRs that were able to record subtitles but these and the SVHS
versions have mainly been withdrawn from the market. VHS machines
used in the AV mode can however record digital subtitling because once
selected the subtitles they form part of the picture. A downside is that the
recording may only be made on the channel selected on the set top box or
41 Standardisation in Digital Interactive Television Final version April 2003 page 4
42 Mr Erkki Liikanen Member of the European Commission, "Convergence and the challenges to Europe's
broadcasting industry" IDATE Conference on Telecom - Internet - Media: Europe Moving On Montpelier, 22nd
November 200
TV for All – Standardisation 32
idTV. Specialist analogue subtitle recording devices are still available such as
Telemole.
Digital VCR’s and PV’s. There are faint signs the digital VCR’s with their built
in decoder may appear on the market. New to the market however are disk
recording devices with local storage known as Personal Video Recorders
(PVR’s). These allow TV programmes to be recorded according to viewers’
preferences by analysing content descriptions (‘metadata’) broadcast along
with TV programmes and comparing these to the preference profile of the
user. It is expected that PVR’s will revolutionize the way people watch
television. Trailer recording, group recording, remote programming and
segmentation offer broadcasters and content providers new ways to attract
and keep their viewers. Proprietary PVR’s, where the consumer device and
metadata service form a closed system, such as SkyPlus, have been
deployed for some time and require subscription.
Open Standards. For more general use however there are clear advantages
for a PVR system similar to the TV-Anytime43 open standards consortium.
Such a system may be considered for standardisation. Of overarching
importance however is that all PVR’s and Digital Video recorders must have
the ability to record and play back subtitles, audio description and signing.
They must also have the ability to record one service whilst another is viewed
on the main screen. It is also recommended that any recording device should
follow the principles outlined in Section 5.1.5 (Interconnections)
11. Retention of Recordings
Experience in parts of Europe has shown that it is possible for previously
recorded material with subtitles to be retained by the broadcaster or subtitling
company then passed to a third party for a later broadcast. The relatively
small fee charged thus obviates the cost of re subtitling the whole programme.
It is suggested that the EBU or body should hold a list of previously subtitled
material that would be available for exchange. Similar consideration should be
given to audio description.
12. Promotion of Assistive Services
Input from representative groups for sensory impaired people to the Working
Group indicates that there is widespread concern for the variable nature of
assistive services across Europe. While some countries are moving towards
high levels of service through quotas mandated by national regulation or
through voluntary schemes by the broadcasters themselves, others are
lacking in any meaningful provision. It is often quoted and argued by
representative bodies that it is a democratic right of all citizens to have access
to television services and especially those of Public Service Broadcasts. A
43 http://www.tv-anytime.org/
TV for All – Standardisation 33
stated aim of the European Year of People with Disabilities44 is “to reinforce
the co-operation between all parties concerned, namely government, the
social partners, NGOs, the social services, the private sector, communities,
voluntary sector groups, people with disabilities and their families”.
Awareness of Services. Mandatory or voluntary assistive services in
themselves are, however, not necessarily sufficient. Recent research45shows
that people over 65 are less likely to be aware of subtitling compared to
younger people. Furthermore, there are still signs that, despite closed
subtitling being available for some 25 years, some viewers do not know how
to access the service. It follows that promotion of assistive services and how
to use them is needed through the whole chain: broadcasters, manufacturers,
point of sale, social services, listings magazines newspapers – indeed any
body that has contact with disabled people. Such promotion can be through:
- details within EPG’s and programmes listings
- programme listing magazines and newspapers
- special promotional advertisements or trailers
- use of a recognised symbol at the commencement of each programme
- point of sale promotion and recognised symbols or tickets on each
device
- awareness by social workers and carers
- representative groups activities/publications, including websites
13. Future developments
SAMBITS. A number of innovative products that might aid assistive services
are coming forward. Not least of these is the SAMBITS (System for Advanced
Multimedia Broadcast and IT Services)46. Supported by leading European
research establishments, manufacturers and representative organisations the
intent is to “bring MPEG 4 and MPEG 7 technology to the broadcast industry
and the related internet services. The project will be able to provide
multimedia services to a terminal that can display any type of general interest
integrated broadcast/internet services with local and remote interactivity.”
A specific proposal within SAMBITS has been made by the RNID and RNIB to
create a SAMBITS terminal in the form of a set-top box that will allow disabled
people to receive digital television and Internet broadcasts. The terminal will
be specifically built to allow individuals with hearing impairment, speech
impairment and/or visual impairment to take full advantage of the broadcasts.
The terminal will require to decode:
a) All available media streams or a selection of available streams
according to the users own abilities and preferences;
44 European Year of People with Disabilities The objectives of the Year
http://www.eypd2003.org/eypd/about/theyear_en.jsp
45 NOP World 420703 January 2003
46 http://www.irt.de/sambits/documents/ibc_SAMBITS_overview.pdf
TV for All – Standardisation 34
b) Captioning and subtitling
c) Signing through either secondary video streams, compressed or
otherwise or by means of an avatar
d) Audio description
“Talking” EPG. WGBH-TV in Boston has created a National Center for
Accessibility to Convergent Media (NCAM). One NCAM project is developing
an Access to Convergent Media Project47 to specifically address the usability
of an electronic program guide (EPG) by individuals who are blind or partially
sighted people thus improving access. Use of the EPG in this way is likely to
enable blind users to successfully interact with other services delivered
through the set-top box such as e-commerce, web browsing, programme
enhancements, and other interactive features. It is understood that similar
work is underway in the UK by the ITC and BSkyB.
Personalisation Agents. The European Design for All e-Accessibility Network
(EDeAN) has drawn attention to the possibility of personalisation agents that
can make it possible for digital systems to automatically track and adapt to
individual user behaviour and preferences. The same type of technology
being used to block children from watching adult material could easily be
adjusted to allow for individualised settings and applications. For example:
adaptation to include descriptive captioning for blind and partially sighted
users, alternative font sizing and colour contrast or adaptable electronic
program guides EPG's. More investigation is needed in order to explore the
potential for the use of PVR's , adaptable programme guides and this type of
new technology with an eye toward adapting it for users with special needs.
Further details on this concept can be found at:
http://www.vtt.fi/tte/samba/projects/adaptive/usability.html
European Research Centre. It is suggested that a European Research
Centre, similar to NCAM, should be formed in order to further develop such
concepts that might not receive the attention of the more conventional
research agencies.
47 http://ncam.wgbh.org/convergence/epg.html
TV for All – Standardisation 35
14. Recommendations
While this report throughout refers to a number of tentative recommendations,
as set out below, it is considered that more consideration is needed before
making any definitive comment. The intent therefore is for the report to act as
a catalyst for stimulating debate both within the TV for All working group and
by other bodies. One such suggestion already made is that the needs for
disabled consumers should be built into television standards. The appropriate
bodies to oversee this would be the European standards bodies CENELEC,
CEN and ETSI. They in turn should establish a disabled users committee to
ensure that they take these issues on board when standards are drafted. This
would ensure the recommendations contained in CEN/CENELEC’s Guide 648-
are implemented by manufacturers are put into practice. This body should
also liaise with manufacturers to ensure that the needs of all consumers are
taken into consideration when products are designed. By no means
exhaustive the following may also be considered:
Adoption of the (Section) 4.1)
Good aerial practice (Section 4.1)
Use of DVB Subtitling ETS 300 743 V1.2.1 (Section 4.2)
Consideration given to Audio Description in the DVB Implementation
Guidelines (Section 4.3.2)
Develop a consensus towards interoperability (Section 4.5 and Section
9))
Development of a single “base line” receiver. (Section (4.5)
Creation of a conformance and certification testing (Section 5.1.1)
Agreement towards standards for receiver control functions, labeling of
switches, dials their sizes (Section 5.1.2), connectors (Section 5.1.3
and connectivity guideline for equipment (5.1.6
Standards towards means of upgrading receivers (5.1.5)
A minimum standard for receiver assistive service decoding ability
(Section 5.1.7).
On-screen displays standards or guidelines for: resolution of “onscreen”
interactive information (Section 5.2).
Standards or guidelines for text, graphics and safe areas (Section 8)
Minimum standards for remote controls: size, shape and usage (5.3),
tactile surfaces and audio alarm when misplaced (Section 5.3.2)
Consider interoperation of remote control units (Section 5.3.3)
Minimum standards and guidelines for EPGs (Section 6)
Subtitling, Audio Description and Signing best practice (Section 7)
Creation of a central register of previously recorded assisted
programmes (Section 11)
Promotion of assistive services by broadcasters, newspapers and by
NRA’s in general (section 12)
The needs for disabled people to be built into standardisation
procedures (section 13)
48 CEN/CENELEC’s Guide 6 “Guidelines for Standards Developers to address the needs of older persons and
persons with disabilities”
TV for All – Standardisation 36
15. Recommendations relevant to CENELEC
As a result from this report being circulated and the proposed meeting in
Barclona 28 October 2003 the final report will contain further comment and
make recommendations in appropriate areas. In the meantime however
in particular it is recommended that CENELEC consider standardisation in the
following areas:
1. Standardise the EBU File transfer format 3264
2. Proceed with standardising DVB Subtitling ETS 300 743 V1.2.1
3. In conjunction with other bodies develop a consensus towards
interoperability with MHP as the main API.
4. Derive minimum standards for receiver control functions, labeling of
switches, dials etc.
5. Develop minimum standards for interconnections and their connectors
to include colour coding.
6. Develop minimum standards for remote controls to include their size,
shape, and buttons for clarity of marking and usage. Also to develop a
set of recognizable symbols to denote functions.
7. Develop a minimum standard for the decoding of assistive services.
That is to say ensure that all DTV decoders sold in the EC have the
ability to decode the main forms of assistive services.
8. Together with EICTA and the EBU establish a conformance centre for
DTV terminals and displays.
9. Together with EICTA develop a standard for a single “base line”
receiver. (As this is being considered by the UK Government’s Digital
Strategy Group there would be a role for CENELEC ensuring that any
standard is applicable Europe wide).
10. Develop minimum standards for upgrading receivers in order to avoid
receiver “legacy” problems. This could be achieved in partnership with
manufacturers.
11. Consider if, in conjunction the EC, it is practicable to produce
standards for on-screen displays derived from the Internet especially
those sites provided by government organisations.
12. In conjunction with the EBU develop standards, or at least produce
guidelines, for a “safe area” to display essential text and graphics.
13. In conjunction with broadcasters explore the possibility of minimum
standards and guidelines for EPGs.
TV for All – Standardisation 37
16.. Conclusion
The unique opportunity offered by the formation of the TV for All Working
Group on standards has the potential to attract a significant proportion of
European disabled people to the use of digital television. If realised then the
resulting benefits will be felt not just by disabled people but also by the wider
population of consumers as a whole.
It has been voiced that many elements towards making an attractively
designed product are relatively simple - costing little more than attention to
such details as clear and understandable labelling. The use of plain language
terminology and the provision of a well designed remote control units with
direct access to essential services would surely have a high value to the user
yet incur only limited cost to manufacturers. Other elements such as the
addition of tactile surfaces, clear on-screen text and intuitive menus are also
unlikely to carry a high cost penalty. It follows that by opening a dialogue with
representatives of disabled people and taking their opinion could lead to many
more small but significant improvements.
To achieve any form of progress in taking these suggestions forward however
will need the co-operation of a number of bodies. Clearly as CENELEC and
ETSI initiated this process they will have a lead role to be play here.
Manufacturers will need to be convinced there is value in making equipment
which really is TV for all people while broadcasters must be confident that
there is a market for assistive services. This process can commence by
CENELEC widely distributing the report, especially the Executive Summary
and Recommendations, to broadcasters (EBU members and non-members),
the Joint Technical Committee, NRA’s and national manufacturing
associations. Once the report is digested open meetings and workshop should
be arranged by CENELEC to seek a constructive dialogue between parties
and determine what is practicable. By taking these initial steps as outlined in
the foregoing paragraphs progress may well be possible before the Barcelona
meeting.
In a similar vein CENELEC are recommended to revisit their Design for All -
Final Background Report, Chapter 7 Digital Broadcasting and the Design for
All - Executive Summary Report, Recommendations for Digital Broadcasting.
These reports contain the wealth of information but they were published in
2000 and since then in the light of Digital Television being introduced in
Europe much has been learnt by manufacturers and broadcasters. It follows
that the Work Items, their Deliverables and Areas of Responsibility may have
changed, as may have the Timetables and Priorities. These should be
reconsidered alongside the recommendations for CENELEC as given in
section 15. Following a revision of the reports they should be published and
given the widest circulation amongst appropriate organisations.
Opportunities should also be taken within the European Year of People with
Disabilities to promote the need for standards. In part this can be achieved by
CENELEC publishing the report on the designated website
http://www.eypd2003.org. It is also hoped that publicity will be gained by
TV for All – Standardisation 38
referring to the Interim Report at the Congress on Media & Disability taking
place in Athens on June 13-14.
It is hoped therefore that this report will stimulate further discussion on how
TV for All can be achieved. At the proposed meeting in Barcelona on 28
October progress so far can be discussed and presented in the final report
due in November 2003. The result of all the above, if successful, could lead to
enhancing Digital Television’s role as the pre-eminent driver in ensuring that
all citizens have a share in the Information Society.
TV for All – Standardisation 39
Glossary of Terms
Accessible Content is accessible when it may be used by someone with a
disability.
API Application Program Interface used in interactivity within a receiver
terminal where software interfaces between the receiver’s own resources and
the form of broadcast applications it receives.
Assistive services and technology. Software or hardware that has been
specifically designed to assist people with disabilities in carrying out daily
activities.
ATSCC Advanced TV Systems Committee originally formed in the US to
investigate the many proponent advanced TV formats that were emerging in
the US during the late 1990’s
Audio Description (AD) An ancillary component associated with a TV
service, which delivers a verbal description of the visual scene as an aid to
understanding and enjoyment particularly, but not exclusively, for viewers who
have visual impairments. The description content is voice only, in mono, and
is typically confined to gaps in the normal programme narrative.
Avatar An image of a human derived by means of a Virtual Reality
application.
CENELEC European Committee for Elctrotechnical Standardisation
CEN European Committee for Standardisation
DTG Digital Television Group comprising broadcasters, manufacturers,
regulators and interested parties
DTT Digital Terrestrial Television
DVB The Digital Video Broadcasting Project industry-led consortium of over
300 broadcasters, manufacturers, network operators, software developers,
regulatory bodies and others in over 35 countries committed to designing
global standards for the global delivery of digital television and data services.
EBU European Broadcasting Union
EICTA European Information Communication and Consumer Electronics
Technology Industry Association
EPG Electronic Programme Guide
ETSI European Telecommunications Standardisation Institute
FCC Federal Communications Commision
MHEG5 Multimedia and Hypermedia Expert Group. A standard for interactive
applications it defines a set of objects that can be arranged into applications.
An MHEG application would typically be used in applications such as digital
TV. The variant MHEG-5 defines the specific classes of object available to the
application creator.
MHP Multimedia Home Platform (MHP) defines a generic interface between
interactive digital applications and the terminals on which those applications
execute. It decouples different provider's applications from the specific
hardware and software details of different MHP terminal implementations.
Agreed by ETSI it has two versions: 1.0.2 for enhanced and interactivity and
version 1.1 supporting Internet access. A further version 1.0.6 is in progress.
MPEG 2/4 and variants Motion Picure Expert Group – the tool box from
which a variety digital trasmission format are based
Navigation Mechanisms and menus The means by which a user can
navigate a page or site.
TV for All – Standardisation 40
NRA’s National Regulatory Authorities
Open Standards An agreed non-proprietary specification free of intellectual
property rights (IPR) and discrimination thus allowing interoperability. The
MHP specification is such an example of an open standard API.
OSG On Screen Graphics
PVR Personal Video Recorder. Recording devices utilising disk storage as
opposed to video tape in a VCR. TVAnytime and Sky Plus are examples of
this.
Screen reader Software program that reads the contents of the screen
aloud to a user. Screen readers are used primarily by individuals who are
blind. Screen readers can usually only read text that is printed, not painted, to
the screen.
TV for All – Standardisation 41
Documentation
eEurope 2005 Action Plan The Framework Directive 2002/21/EC
The Universal Service Directive 2002/22/EC
Independent Television Commission News Release 19/03
Independent Television Commission and Consumers Association “Easy TV
2002 Research Report”, 7th January 2003
CEN/CENELEC Guide 6 Guidelines for standards developers to address the
needs of older persons and persons with disabilities Edition 1 / January 2002
DTG “D” Book V 3.2 February 2001 EU report “Barriers to widespread access
to new services and applications of the information society through open
platforms in digital television and third generation mobile communications.
2003
Standardisation in digital interactive television Strategy and recommendations
for a standardisation policy supporting the effective implementation of the
Framework Directive 2002/21/EC and the establishment of required
interoperability levels in digital interactive television Final version April 2003
http://www.irt.de/sambits/documents/ibc_SAMBITS_overview.pdf
Design for All ICTSB 15.05.2000
EC Framework Directive 2002/21/EC March 2002
Communications Technologies ICT Standards Board 1999 Design for All Final
Report 2000,http://ncam.wgbh.org/convergence/barriers.html
ITC and Consumers Association Easy TV Research Report January 2003
ANEC Consumer Requirements in Standardisation relating to the Information
Society January 2003 (ANEC2003/ICT/008)
CEN/CENELEC Guide 6 “Guidelines for standards developers to address the
needs of older persons and persons with disabilities” Edition 1 January
200219.
Report on Standardisation in Digital Interactive Television by Contest
Consultancy 4.1 v
Web Content Accessibility Guidelines 1.0 W3C Recommendation 5- May-
1999 (http://www.w3.org/TR/WAI-WEBCONTENT/).
Pictograms, symbols and icons to assist users of the telephone service. ITU-T
F.902 (02/95),
TV for All – Standardisation 42
Interactive services design guidelines. ITU-T F.910 (02/95)
http://www.tiresias.org/guidelines/television.htm
Consumer Requirements in Standardisation relating to the Information Society
January 2003 NEC2003/ICT/008 http://www.cenorm.be/isss/
http://www.ict.etsi.fr/DATSCG/DATSCG_home.htm
Subtitulado para personas sordas y personas con discapacidad auditiva.
Subtitulado a través del teletextoCONTIENE LAS ÚLTIMAS
APORTACIONES AL 5 DE FEBRERO DE 2003 (PNE 153010)
ETSI Enhanced Teletext specification ETS 300 706
VBI Subtitle Mapping to DVB Subtitles Version 1 (Subtitles group of the U.K.
Digital TV Group).
EBU 3264 Subtitle File Format
RNIB Briefing paper “How standards can improve Access of Blind and
Partially sighted people to Digital Television: the role of European
Standardisation and the EU institutions” 27 March 2003
Deaf Broadcasting Council (DBC) “E
Essential elements in ensuring that deaf people in Europe enjoy full access to
the Information Society”
March 2003
Draft FEPEDA Policy on Television Broadcasting for deaf and hearing
Impaired children 24/5/99
Workgroup "Subtitling and Sign-Language" (Arbeitsgruppe Untertitel und
Gebärdensprachdolmetschereinblendung")
MyTV http://www.extra.research.philips.com/euprojects/mytv/
ES 201 381 V1.1.1 (1998-12) Human Factors (HF); Telecommunications
keypads and keyboards; Tactile identifiers
Submission to the EC on Subtitling and sign language – Television Without
Frontiers directive RNID 29 July 2002
TV Broadcasting for All List of Domains. RNID April 2003
TV for All – Standardisation 43
Organisations providing input to TV for All
Asociación Española de Normalización y Certificación (AENOR) European
ANEC European Association for the Co-ordination Representation in
Standards
DBC Deaf Broadcasting Council
European Disability Forum, EDF
European Federation of Hard of Hearing (EFHOH) EFHOH
European Federation of Parents of Hearing Impaired Children (FEPEDA) FEPEDA
Hearing Concern
European Design for All e-Accessibility Network (EdeAN)
RNID
Royal National Institute of the Blind, UK RNIB