Assisted GPS

In my previous article, I gave a basic look into the global positioning system, or GPS. In this article, I will describe what Assisted GPS is and how it is used in modern day technology. We have taken a once government limited technology and turned it into something that is more beneficial to the common consumer. Whether it be for fun or utility, GPS has proven to be a great technology and the advent of Assisted GPS is fast becoming a more powerful (and entertaining) alternative.

Assisted GPS (A-GPS), as defined by Wikipedia, is a system that "...enhances startup performance of a GPS satellite-based positioning system." This system provides for a much more accurate location lock and it has been proven key in emergency situations in which the standard GPS signal is inaccurate due to a multitude of factors. These factors can include severe weather conditions and the surrounding environment in which the GPS unit is being operated. For example, if the device is used around many tall buildings or indoors, the signal is generally degraded and may be completely unusable. This poses a problem to emergency operators who need to be relayed the device's location in the event of an emergency. If the only way to relay a position to an operator is through the standard GPS coordinates, a person may be rendered completely helpless. This is where A-GPS shines.

A-GPS is a bunch of technologies all rolled into one that has the ability to gather more accurate position information from surrounding cell towers and Wi-Fi networks. Cell towers are vastly more powerful than standalone devices and they carry the ability to compare fragmented location signals from those standalone devices with the ones that they receive from the GPS satellites. In addition to cell towers, devices which are Wi-Fi enabled may turn to Wi-Fi networks to provide an additional means of device location. In these cases, the device will "sniff" available Wi-Fi networks and compare various factors such as signal strength to a database to allow an additional means of location. Right now, I am using Apple's iPhone which performs both of these feats. It uses the standard GPS signals, combined with cell tower and Wi-Fi tracking to give a quick, accurate description of the device's location.

In areas where standard GPS simply will not cut it, other technologies are stepping up to fill the void. It is important to note that not all devices come with these additional capabilities, but as time comes to pass these technologies are likely to find themselves implanted in more and more devices. Speed and accuracy are the two main goals of any GPS system and we have combined various technologies to improve each of these.