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Telecommunications

The conventional fixed-line telephone (ie plain old telephone system) has provided enormous benefits for many people with disabilities and older people. However the evolution from being solely an audio system to one which also carries data has introduced new possibilities as well as new problems.

Additional services, such as caller line identification and email, may require the use of a screen to display text and possibly graphics. These screen phones pose obvious problems for people with a visual or cognitive impairment, but there are methods for alleviating these problems.

Video phones have been slow to make significant market penetration. This is attributable to the low bandwidth available to most domestic consumers. For deaf users, a video phone could transmit sign language with a modest picture quality, but greater bandwidth is needed for lip reading.

Mobile communications are spreading, not only in quantity but also in diversity. More and more applications that either extend the traditional pattern of fixed communications or are entirely novel are appearing on the mobile market, with increasingly shorter times between launching events. This speed of development poses new problems on how to incorporate inclusive design in the development process.

The significant difference offered by the new systems is one of speed (see Table 1). For voice communication this difference is not significant, but for transferring large quantities of data, such as in video telephony or access to the web, the telecommunication companies are convinced that it is commercially viable.

Table 1 Maximum data speed of mobile systems

Generation

Type

Maximum speed kbps

1

Analogue

 

2

GSM

9.6

2.5

GPRS

100

2.5

EDGE

384

3

UMTS

2000

The analogue systems are being largely superseded by digital systems except in remote areas where there are large distances between base stations.

The GSM (Global System for Mobile communications) digital system overcame many of the problems of poor signal reception in the analogue systems and increased available network capacity, but caused significant problems for many users of hearing aids.

With GSM systems the short message service (SMS) has proved very popular particularly among teenagers since it is inexpensive. The user interface is usually just the basic numeric keypad on the mobile phone, which requires multiple key presses with time sensitive input. This causes a significant problem for anyone with poor manual dexterity or a hand tremor.

WAP (Wireless Application Protocol) provides slow access to special websites. The service has not proved popular because of the slowness, the limitations of the small display on the mobile phone handset and the very limited number of services available. However the more advanced I-Mode system in Japan has proved a commercial success.

Extra functionality could be built into a WAP phone to suit disabled individuals, 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 (EN 1332-4), 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.

GPRS (General Packet Radio Service) is a high-speed packet data technology, which, together with WAP, offers a means of upgrading GSM services towards the third generation systems. Use of GPRS will permit data transmission speeds over GSM networks of up to 100 kbps. Unlike GSM, GPRS systems are always connected so there is no delay caused by having to log on to the system.

UMTS (Universal Mobile Telecommunications System) is the third generation, after GSM and the analogue first generation, of mobile telecommunications systems. It should have seamless operation between terrestrial and satellite links, and will provide high-speed access to the Internet with data rates of up to 2 Mbps 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 infrastructure, will make the licence holders anxious to recover their outlay as quickly as possible by concentrating upon the most profitable sectors. They may be very reluctant to extend the service beyond these sectors and to provide tariff packages that would be attractive to disabled people and other disadvantaged consumers.

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.

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 is one example of a short-range wireless technology that can link appliances and devices together, so that control and communication can be managed remotely. It offers a number of very interesting and important applications for people with disabilities. Small devices that have tiny knobs - mobile phones, hearing aids, pocket calculators etc. - could be controlled from a separate keypad, appropriate to the user's needs, connected via a Bluetooth link. This is of great significance because the mobile phone itself could replace the remote control for televisions and video recorders. It can provide an interactive channel (for services such as tele-shopping) while connecting to the television via Bluetooth.

There has been much discussion about developing special mobiles with better accessibility, but all efforts to develop dedicated mobile phones for disabled people have been rejected, by disabled people themselves because they do not wish to be stigmatised as 'abnormal', and by the manufacturers because they regard this market as too small to be viable. The mobile phone business is characterised by high sales volumes and low prices with short product life spans. Dedicated products aimed at specific parts of the community tend to be made in low volumes, at high prices, and with long periods between design updates. This does not make them attractive for manufacturer or consumer.


Relevant standards

Further information

 

 

Last updated: 02.10.2008   © Copyright reserved