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Inclusive Design of Wireless Systems

John Gill

 


Summary

The aim is to promote a culture of inclusion, that will emphasise awareness of the inclusion philosophy throughout the telecommunications industries.  This will involve extending the database for designers on consumers and their requirements, so that many more disabled and elderly people can be catered for in mainstream design.  Also establishing a forum where inclusion and accessibility issues can be freely and frankly explored with representatives of the telecommunications industries.  It will also be necessary to facilitate consumer awareness of the possibilities and potential of ICT developments, in order to encourage informed choice and demand.  The end result should be that disabled and elderly people are enabled to participate in the benefits of 3rd generation mobile communication systems from the outset, as discriminating consumers but not discriminated against.

 

Impairments
A significant proportion of the population has impairments which reduce their ability to effectively use standard consumer products, such as the telephone. The impairment groups described here have been defined in terms of their functional ability, or lack of it, and how this relates to the use of telephones.

It is not uncommon for an individual to have more than one impairment; this is particularly common among older people.  The proportion of the population with impairments increases with age. The number of people over retirement age in Europe is likely to increase by over 1% per year for the next two decades, and as a result the number of impaired people will also increase.

Table:  Estimated population of European Union (population 385 million) aged 65 and over

Year

Estimate

1990

82 million

2000

90 million

2010

105 million

2020

120 million

2030

138 million

Much of the data on the numbers of people with impairments is derived from clinically based studies, which tend to use diagnostic measures rather than functional ones. These tend to produce figures showing the numbers in the population with hearing loss exceeding particular values, or the extent of specific conditions, such as multiple sclerosis. While such results are important for clinical management and resource allocation, they do not provide reliable information on the need for aids to mobility, hearing or vision. It is possible, with extreme care, to make some extrapolations from one data set to another, but usually only on the basis of some direct practical experience.

The user groups described here have been defined in terms of their functional ability, with specific emphasis on use of telephones, so that the needs of each might correlate with a particular set of equipment parameters. At the same time, it has been necessary to avoid straying too far from the more conventional descriptors, so that valid extrapolation of data can still be attempted. For example, 'Hearing impairment (moderate)' applies to a user group which employs hearing aids occasionally but does not need them when telephoning, while 'Deaf' corresponds to a user group which cannot use voice telephony and must resort to text or other visual modes. In attempting to estimate numbers in each user group, no account has been taken of multiple impairments.

In the elderly population in particular, there may be a tendency towards hearing, vision and mobility impairments arising in parallel. Therefore, while the numbers are 'best estimates' for single groups of users, they should not be aggregated. The group sizes have been estimated conservatively and very much larger numbers would be obtained if lower levels of impairment were included. For example, over half of the population needs some form of optical correction, and about one sixth has a clinically significant level of hearing loss. The lower levels of impairment will not normally lead to difficulties in using telephone terminals but can cause problems in adverse circumstances.

 

Estimated Numbers in the European Union (population 385 million)

Hearing impairment (moderate)

16 million    

Hearing impairment (severe)

4 million

Deafness

2 million

Visual impairment (moderate)

3 million

Visual impairment (severe)

2 million

Blindness

1 million

Deaf-blindness

0.2 million

Speech impairment (moderate)

3 million

Speech impairment (severe)

2 million

Limited dexterity

7 million

Limited use of hands/arms

5 million

Weak grip

7 million

Hand tremor

7 million

Cognitive impairment

9 million

Restricted mobility (lower limb)

22 million

The problems of ageing are often underestimated.  For instance, in a person aged 60 with 'normal' eyesight, about one third as much light reaches the retina as when they were 20. Therefore older people often have problems operating controls when there is low illumination.  Older people adapt at a slower rate to changes in the ambient illumination, which can give problems when the illumination on a control panel is greatly different to what is being viewed or controlled.  The term 'accommodation' is used to indicate the ability of the eye to change its focus, and thus get a clear image on the retina. The gradual decline in accommodation is inevitable with age.

Total colour blindness is uncommon (less than 0.0025% of the population).  However over 10% of males, but less than 0.5% of females, have problems in distinguishing red/green. Loss of sensitivity to blue/yellow is usually a consequence of eye disease.  Even though these problems with differentiating colours affects a significant portion of the general population, designers frequently fail to take this into account when designing new terminals.

 

Telecommunication Systems
Technological developments have helped people with disabilities, but they have also resulted in extra problems. For instance the increasing use of terminals with visual displays, such as cash dispensers and mobile phones, mean that access to services may be restricted for those who cannot read the visual display.

The general approach has been to encourage designers to incorporate features in the standard product which will help people with disabilities. If this is insufficient, then to incorporate a standard method of connecting the user's own device which has an appropriate user interface. But if neither of these approaches provides a satisfactory solution, then special equipment will be needed.

WAP (wireless application protocol) can be used for financial transactions such as reloading an electronic purse. Extra functionality to suit disabled users could be built into the terminals, but this in itself is unlikely to provide full access to services. Therefore it will be necessary to modify the server or proxy server. The WAP User Agent Profile Specification covers aspects of the technical interface and the User Preference Profile concerns content selection (eg the user is interested in receiving sports scores); neither of these profiles covers the needs of people with disabilities.

This could be done in the form of a user profile which is stored on the smart card in the user's phone. There is a European standard, but this will need to be extended to allow for the facilities needed by mobile phone users who have disabilities. This standard already incorporates facilities for specifying preferred text size, screen colour and speech output of the contents of the visual display.

It is already being suggested that WAP-enabled GSM systems, upgraded by GPRS (General Packet Radio Service, see box for details), will provide most of the intended function of third generation networks at a fraction of the infrastructure cost. This raises the possibility that some network operators will pause at that point in order to re-coup some of their high outlay - before incurring very heavy additional costs. Consumer acceptance of WAP systems, and their accessibility to disabled and elderly people, therefore need to be examined very carefully as the consequences for future services could be critical.
UMTS (Universal Mobile Telecommunications System) is the third generation, after GSM and the analogue first generation, of mobile telecommunications systems. It will have seamless operation between terrestrial and satellite links, and will provide high speed access to the Internet with data rates of up to 2 Mbit/s for a stationary terminal, less when on the move. It will include packet data transmission with the potential to adjust bandwidth on demand for asymmetric traffic. In the UK and Germany the network licences have been sold by governments for vast sums (the first five UK licences sold for over £22 billion), which will have to be recouped from the consumers. This, in addition to the start-up costs for a new infra-structure, may make the licence holders anxious to recover their outlay as quickly as possible by concentrating upon the most profitable sectors. They may be reluctant to extend the service beyond these sectors and to provide tariff packages that would be attractive to disabled people and other disadvantaged consumers. It will be most unfortunate if this does happen, because third generation services such as UMTS have so much to offer them.
The high bandwidth and the text facility available with UMTS mean that text messaging could be as cheap and straightforward as voice calling, because the bandwidth would be paid for 'on demand' and not during waiting periods. It seems highly probable that this technology will transform the way that deaf people use text telephony and will put it on a par with voice telephony - indeed it may be that text users come to enjoy an advantage over voice traffic. There is a problem with this, although not one that the mobile networks can solve. The text protocols on these digital mobile networks will not be compatible with those used for analogue text telephony on the fixed networks, and although the fixed network operators can solve this problem up to a point it would not be a long term solution. Once UMTS is able to offer wide geographical coverage at affordable tariffs, textphone consumers will want to migrate to the new and better services. Their existing terminals will be obsolete and they will have to purchase new ones. This is the point where some managed conversion from the old technology to the new would seem to be only fair and equitable.
Special services which UMTS might offer include:

Realisation of these possibilities depends upon the third generation services developing quickly to the point where they reach, and are used by, the great majority of the general public.

Bluetooth
There are an increasing number of self-service terminals such as cash dispensers (ATMs) and ticket selling machines for public transport.  These terminals give a number of problems for disabled users which could be alleviated using Bluetooth:
(a)        A wheelchair user may not be able to reach the buttons on the terminal.  A hand-held terminal (such as a PDA or a mobile phone) could be connected to the terminal via Bluetooth.
(b)        A blind person may have difficulty in locating the terminal; a Bluetooth signal to the terminal could trigger an audible location signal from the terminal.
(c)        A blind person might want speech output of the information on the terminal's screen; this could be transmitted via Bluetooth to a mobile phone handset.

The user interfaces on many domestic devices (from washing machines to mobile phones) are difficult to use by people with visual, hearing, physical or cognitive impairments.  So the ability to have an alternative user interface, connected via Bluetooth, could make all the difference to their ability to use the equipment. 

Visually impaired people often have difficulty in determining whether it is safe to cross the road at traffic lights or the destination of a bus.  If the traffic lights and buses had Bluetooth transmitters, the blind person could receive an audible message in a hand-held device such as a mobile phone handset.  Such a system could be extended to giving road names at road junctions.  It could also be used in indoor environments such as shopping centres or railway stations.

Hearing aid users have particular problems in noisy environments, and a radio-based system would permit the connection of public address systems to their hearing aids; this would be useful in public places such as railway stations, theatres and at sports events. 

Visually impaired people often have difficulties in following the plot on television or in the cinema.  One solution is to insert an audio description in the gaps in the dialogue.  However such a commentary can be annoying to other people, so it is desirable that only the visually impaired person hears the audio description.  One possibility would be to use Bluetooth to transmit to a headset worn by the visually impaired person.

Typefaces

Inclusive design is not just about high technology solutions, it includes more obvious matters such as the choice of typeface.  Too often designers of telecommunication terminals use Arial or Helvetica fonts for the numbers on keys, when it would be much better to use a font with ‘open’ numerals.

Arial 3 6 8 9

 

With email addresses and passwords it is essential that font clearly differentiates the number 1, capital I and lower case l.

 

Inclusive Design
The 'inclusive design' message has had limited practical impact upon the area of information and communication systems and services. This is despite considerable effort being expended by various groups around Europe.

Inclusive design is not just adding an extra feature to a product to meet the perceived needs of a disabled user. It is a process, like quality, which has to be considered at every stage in developing a new product or service. This requires companies to promote a culture of inclusion within their organisation. It also requires detailed technical guidelines on the design features required by the various groups of disabled users.

In the case of cash dispensers, the companies manufacturing the equipment see their customers as the banks purchasing their equipment. Even though they may have incorporated inclusive design features in their range of terminals, it is to no avail if the bank is not interested in offering it to their customers. Within the bank it may be a technical department which is responsible for selecting equipment for the bank, but it will be the local branches who have direct contact with disabled customers and who may provide a modicum of training in the use of the cash dispenser. Unfortunately local branch staff are unlikely to be aware of the technological possibilities for improving the accessibility of the equipment.

At the policy level it may be sufficient to specify that the equipment and services must be accessible to as many people as is reasonably possible. However this leaves open many questions including what does ‘accessible' mean? Also what is 'reasonable'? Also it does not cover the often crucial question as to who pays for any additional costs such as training.

The development of guidelines for inclusive design of systems and services in the area of information and communication technologies is seriously hampered by the sparcity of sound scientific data about the needs of people with disabilities. What data exists is all too often based on inadequate sample sizes or inappropriate methodology. This is an area which is perceived to be low on academic content.  Industry wants guidelines to be pan-disability, but this will require greater collaboration between all the relevant organisations representing the different disability groups.

With new equipment and services which are only in the early stages of specification, such as third generation mobile communications, it is difficult to be precise. However if the influencing is left to the stage when it is clear what features will be incorporated, it is often too late to get anything significant changed.

Information for product designers may be detailed design guidelines (eg the maximum height and angle of a display so that it can be read by a wheelchair user). However this approach is only possible for established technology for which detailed design guidelines exist. In other cases it will be necessary to provide generic guidelines backed up by recommendations on how to test prototypes with a cross-section of potential users. For telecommunication designers the problems are shortage of time and lack of an established system for evaluating with disabled users. This is an area where user organisations could take a more active role in providing speedy evaluation of prototype systems and services.

Standardisation

Standards are crucial in the telecommunications industry where there is a rigorous, but if sometimes slow, process for developing standards. In the television industry, the process is somewhat different in that the technical standards are frequently determined by bodies made up of only industry representatives and there is no policy for involving consumers. The situation is different again in computer software where the commercially dominant players set the de facto standards with apparently no consultative process. This means that convergence is going to involve a clash of cultures as well as the more obvious problems of integrating three different groups of technology.

Standardisation is slow, time consuming, lacks academic content and sometimes has limited direct commercial benefit. Academics shun the area since it does not produce research publications. Industry is hesitant about inclusive design standards work since they can see no short-term commercial benefit.

Industry and many government departments feel it is the role of the organisations of disabled people to assist with the implementation and awareness phases. However the disability organisations have often taken the view that they should be paid to do this work.

Since governments now see the primary purpose of standards as facilitating trade, the role of the consumer has become somewhat uncomfortable. Therefore legislation or mandatory regulation would appear to be the only practical way of requiring commercial organisations to adopt inclusive design principles. However the current trend is towards minimising regulatory control, and European legislation does not appear likely in the near future.

Standardisation has four phases:
1.         Deciding what needs to be standardised and finding experts to participate in the work.
2.         Writing the precise standard; this requires detailed technical knowledge as well as good understanding of the implications of various impairments.
3.         Implementing the standard (ie encouraging the key players to take it up).
4.         Publicity so that disabled people are aware (eg the significance of the tactile danger warning on packaging containing dangerous substances).

Lack of appropriate standards at the right time can be a major problem.  For instance, there is an urgent need to standardise protocols for the short-range radio connection of assistive technology devices to mainstream terminals; if there is no standard in the near future, disabled people will not benefit from developments such as Bluetooth.

The Future

Although there are exciting possibilities for harnessing new ICT to make life easier for people with disabilities, there is still likely to be an increasing gap between the disabled and able bodied communities.  The main cause is that commercial organisations do not perceive short-term profits from addressing the needs of disabled customers, and there is inadequate regulatory and legislative provision in Europe to protect their needs.

The European regulatory system which separates networks and terminals works against people with disabilities who need end-to-end communication.  It also leaves unresolved the problem of who pays for special terminals.  In most European countries, disabled people feel that they should not bear the cost of such provision.

Accessibility of third generation mobile systems appears to be a lost cause, but it is hoped that the European Union can put measures in place in time to rectify this situation for fourth generation systems.

One step in the right direction is the recent establishment of a forum where the telecommunications industry can discuss inclusion and accessibility issues with disability organisations. 

 

Further Information
Gill J M (ed)   Guidelines for the Design of Screen and Web Phones to be Accessible by Visually Disabled Persons.  ISBN 1 86048 018 7, December 1998, 28 pp.  Also at http://www.tiresias.org/reports/webphone.htm

Gill J M  Approaches for Influencing the Design of New Telecommunication Systems and Services.  International Conference on Smart Homes and Telematics, Eindhoven, February 1999.  Also at http://www.tiresias.org/reports/approach.htm

Gill J M & Shipley A D C   Telephones: What Features do Disabled People Need?   PhoneAbility, ISBN 1 86048 020 9, August 1999, 28 pp.  Also at http://www.tiresias.org/phoneability/telephones

Gill J M  New European Standards on the Man-Machine Interface for Card Systems.  Royal National Institute for the Blind, August 1999.  Also at http://www.tiresias.org/reports/en1332.htm

Gill J M   Telecommunications - Guidelines for Accessibility.  COST 219bis, ISBN 1 86048 022 5, October 1999, 24 pp.  Also at http://www.tiresias.org/telecoms

Gill J M  The Challenge of Convergence for Inclusive Design.  February 2000.  Also at http://www.tiresias.org/reports/ccid.htm

Gill J M   Mobile Telephony: Will Future Developments be Accessible to Visually Impaired Users?   Rehabilitation International Conference on Mobile Telephony, Potsdam, Germany, June 2000.  Also at http://www.tiresias.org/reports/potsdam.htm

Gill J M   Design Features of Terminals to Improve Accessibility by Visually Impaired Persons.  In Stuen C et al Vision Rehabilitation: Assessment, Intervention and Outcomes, Swets & Zeitlinger, ISBN 90 265 1631 2, August 2000.  Also at http://www.tiresias.org/reports/terminal.htm

Gill J M  Which Button?  Designing User Interfaces for People with Visual Impairments.  ISBN 1 86048 023 3, September 2000, 28 pp.  Also at http://www.tiresias.org/controls

Gill J M  Tiresias: A Family of Typefaces Designed for Legibility on Screens, Signs and Labels.  RNIB, September 2000.  Also at http://www.tiresias.org/fonts

Gill J M  Bluetooth: Can It Help Disabled People?  Incisor, October 2000.  Also at http://www.tiresias.org/reports/bluetooth.htm and http://www.click.co.uk/inc_oct2000.pdf

Gill J M   Keeping Step?  Scientific and Technological Research for Visually Impaired People.  RNIB, ISBN 1 86048 025X, February 2001.  Also at http://www.tiresias.org/keeping_step

James G A & Gill J M  Recent Developments in the Production and Design of Tactual Maps and Diagrams in the United Kingdom.  International Conference for the Education of Blind Youth, Madrid, 1972.

Shipley A D C & Gill J M  Call Barred?  Inclusive Design of Wireless Systems.  PhoneAbility, ISBN 1 86048 024 1, December 2000.  Also at http://www.tiresias.org/phoneability/wireless.htm

 

 



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