Assisted GPS navigation systems

Motorists in Malaysia are starting to rely on GPS navigation systems. But these systems occasionally fail in underground car parks or inside tunnels. Here how Assisted GPS comes to the rescue. Traditional GPS relies on line-of-sight with orbiting satellites. But in a city this may not always be possible. So when you try to wedge between two skyscrapers, or drive inside tunnels on the expressway, you’ll notice that the satellite signal weakens, and your GPS unit is unresponsive or dies completely.

New GPS devices and cell phones support a feature called Assisted GPS [ to minimize disruption in navigation services. A-l complements traditional GPS and relies heavily on the grid of cell communication towers to compute your exact location. So when the satellite is momentarily out of reach, A-GPS takes over.

In this article we’ll explain how a cell phone uses the A-GPS feature. Some phones use three different systems to determine its location: GPS, A-GPS, and Wi-Fl hotspots. Theoretically, a device could use any of these navigation systems independently, without relying on the other two. Of course, you get accurate and faster results when using complementing navigation systems such as GPS with A-GPS.

The Assistance Server is the key component in an A-GPS system. The server [ is set up by the carrier) communicates with the cellular network. It receives your location from the cellular network and relays it to your phone. The cellular towers and base stations also have GPS receivers and communicate with the satellites. So the assistance server also relays this information to the GPS receiver in your phone. Your phone communicates with the Assistance server via its GPRS connection.

One who uses A-GPS enjoys the following benefits. When he switches on the phone, it takes a shorter time to first fix with the satellite. That means it gets the orbit and clock data from the satellites quicker. Secondly, less processing is required from the OPS receiver, thus saving battery life. Of course, the biggest advantage is location information indoors.

If you want to try out one of this GPS, here’s where you can get it.

Source:Brian Pereira