Researchers from Delft University of Technology, Vrije Universiteit Amsterdam and VSL have created an alternative positioning system that is more reliable and accurate than GPS, especially in urban environments. The working prototype used to demonstrate this new mobile network infrastructure had an accuracy of 10 centimeters.
The implementation of various location-based applications such as driverless vehicles, quantum communication and next generation mobile communication systems depends on this new technology.
Global navigation systems such as EU Galileo and US GPS are an essential part of the underlying infrastructure. However, these satellite-dependent systems have their drawbacks and weaknesses. On Earth, radio signals are weak and if they are reflected or blocked by structures, precise positioning is no longer possible.
According to Christiaan Tiberius, research coordinator and professor at Delft University of Technology, “this can make GPS unreliable, for example, in urban environments, which is a problem if we want to use driverless vehicles. In addition, GPS is used by both the public and our government for various location-based services and navigation tools. Also, we didn't have a backup system yet.”
The goal of the SuperGPS project was to create an alternative positioning system that could be more reliable and accurate than GPS, using the mobile telecommunications network instead of satellites.
According to Jeroen Koelemeij of Vrije Universiteit Amsterdam, “We realized that with a few cutting-edge developments, the communication network can be turned into a highly accurate alternative positioning system independent of GPS.” “We have succeeded in creating a system that can connect in the same way as existing mobile and Wi-Fi networks and deliver precise positioning and time distribution in the same way as GPS.”
Navigation System with Atomic Clocks
One of these developments involves connecting the mobile network to a very precise atomic clock so that it can broadcast precisely timed positioning messages, just as GPS satellites do with the aid of atomic clocks they carry.
The existing fiber-optic network is used to establish these connections. According to Erik Dierikx of VSL, “We were already looking for methods to transmit the national time generated by our atomic clocks to outside users via the telecommunications network.”
“With the help of these methods, we can transform the network into a widely distributed atomic clock with a wide variety of new uses, including extremely precise positioning over mobile networks. Theoretically, anyone can wirelessly access the national time produced in VSL with the hybrid optical-wireless technology we have proven before. In essence, it creates an incredibly accurate radio clock in billionths of a second.”
This technology also uses radio waves with much wider bandwidth than is typically used. “Buildings can deceive navigation devices by reflecting radio signals. The wide bandwidth of our system helps separate these confusing signal reflections and supports higher positioning accuracy,” says Gerard Janssen of Delft University of Technology.
“Also, radio spectrum is expensive due to lack of bandwidth. We circumvent this by distributing several closely linked, narrow-bandwidth radio signals over a sizable virtual bandwidth. The advantage is that only a small fraction of the virtual bandwidth is actually used and the signals can be quite similar to cell phone signals.”
📩 16/11/2022 19:24