A new breakthrough could allow scientists to overcome the problems with GPS, according to scientists.
In recent years, positioning technology has become so reliable that it has reshaped the world, allowing people to easily locate themselves using just a small device such as a phone. But that technology continues to face problems, particularly in built-up, busy areas or when indoors.
A new system avoids those problematic satellite signals and instead allows people to locate themselves using phone signals, according to those who have discovered it.
It does so using what they call a “hybrid optical-wireless system”. That works by connecting a variety of base stations together in busy areas, and using them to locate a device.
The system can currently find people to within 10 centimetres, the researchers report in a new paper in Nature. With further improvements, that could be reduced to just a centimetre.
The current problems with satellite positioning is largely that they need an unobstructed view of the sky to work. That is a result of the technology that powers them: they must connect to a number of satellites, and then use them to calculate their location because their positions are always known.
Without a view of the sky, however, such systems do not work properly. That can pose problems for people looking to navigate while indoors or while around high buildings – and it is exactly in such urban areas that accurate positioning is most used.
What’s more, satellite positioning systems are vulnerable to a whole host of other weaknesses. The radio signals can easily be jammed or forged, either to make it difficult to get a position or even make people think they are somewhere else entirely.
The researchers aimed to overcome those problems by building a system that does not rely on a view of the sky and can still allow for precise positioning of a device on the Earth.
It consists of a set of radio transmitters, which are all looped together using fast ethernet cables. It uses similar techniques to those that power mobile communication networks, but uses them for reliable and precise tracking.
Phones are already able to use those mobile networks to get their rough position. But on their own they cannot be accurate because they are not synchronised in the same way as satellites, and even the briefest difference in time can cause major errors, because the signals travel so fast.
The use of fast ethernet cables overcomes that problem, the scientists write, by allowing the various baser stations to be attached to each other.
The system is one of a range of new technologies being developed that could allow for pinpoint accuracy in even built-up areas, alongside other systems such as new materials that can be coated on walls and allow devices to better locate themselves.
“These developments will all lead to improved location information that is expected to have exciting applications in a future network known as the Tactile Internet, which will provide information through touch, as well as visual and auditory signals,” write independent experts Hui Chen and Henk Wymeersch in an article that accompanies the researchers Nature paper.
“Accurate positional information could lead to ‘smart cities’, in which homes automatically turn on heating as their occupants get closer, and drones that deliver packages to recipients on the move.”
The work is described in a paper, ‘A hybrid optical–wireless network for decimetre-level terrestrial positioning’, published in Nature today.