Over the next few years there is likely to be a dramatic increase in services for the general public which are based on knowing your location. Satellite navigation in cars is already widely used. A mobile phone handset is another device on which it will be possible to request the location of the nearest bank and be provided with instructions on how to reach it.
What are location-based services?
Location-based services are information and entertainment services accessible with mobile devices through the mobile network and utilising the ability to make use of the geographical position of the mobile device.
The possible scenarios for providing people with specific information at a location, or about their location, could allow a blind person to carry a device which received audible information about where they were, what their surroundings were like and what was available. This person could set their device to only provide information on such things as the route they could take to reach a destination. The complexity of information could vary depending upon the place. A railway station would provide information on ticket machines, platforms and other facilities. A road junction may only provide information on options for crossing the road and which directions a person could take.
It would be possible to place information ‘tags’ on devices at every important place. These could allow all people to carry a device to pick up the information.
Another advantage for a blind person who did not know their way around, would be an alert that told them that they were travelling in the wrong direction. If they had set their device to help them get to a certain place, the system could interact with them to guide them accurately to their destination.
There are many questions that arise about how to make these scenarios workable. For example, how would the information be kept up to date, especially for problems such as road works or detours on pavements? However, the possibilities to help people with disabilities and provide innovative services mean that location based systems should be developed.
Emergency services often need to know the precise location of an incident. A blind user may not be able to describe their position, so the ability to transmit information specifying their location could be invaluable. Ideally, the alarm system that operates in and around their home should also work when they are away from home without the user having to do anything.
There have been a number of trials of stand-alone electronic beacons; commonly these use infra-red or radio to give prerecorded audio messages for the blind pedestrian. However, the difference between these and the new systems under development is that the new systems will be part of an integrated network. They will use short-range radio technology such as RFID, Bluetooth, WiFi and WiMax.
These short range systems will be used in conjunction with long range systems, such as mobile phones, where the network knows the approximate position of the user. For more accurate positional information, the systems may be supplemented by satellite positioning systems (such as the American GPS, the Russian GLONASS or in the future, the European Galileo system). These systems predominantly rely on line-of-sight to a number of satellites and so have low levels of coverage indoors, and relatively poor position accuracy when used in urban canyons. However, the latest high sensitivity receivers, and a technique known as ‘Assisted GPS’ will improve indoor coverage and the accuracy and availability in urban canyons.
Information about one's position is of limited use unless it can be related to the real environment. So these systems are usually linked to a database which may include information normally found on a map plus other related information (e.g. the scheduled times of buses from a particular bus stop or the time until the next bus arrives). In addition the database could include accessibility information.
For location based systems to be of practical benefit to blind people, they must be:
- Easy to use
- Provide output in an appropriate form (e.g. speech)
- Contain up-to-date information
- Not invade privacy
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