GPS
In an "open sky" environment, GPS can be a highly accurate location technology providing location accuracy of between 10-15m. However, when used indoors or in dense urban areas, problems with availability and accuracy quickly become apparent. Additionally, GPS startup times (or time-to-fix) can take minutes, even in optimum environments.
As location based services move to the mainstream, consumers are demanding location information that is accurate (in all environments) and fast. These expectations can not met by GPS or A-GPS.
XPS 2.0 and GPS
In order for GPS to provide a location reading, at least four satelites must be acquired by the GPS device. With XPS, a fix on just two GPS satellites can improve overall accuracy of a location reading.
- GPS increases the accuracy of location estimates by allowing Wi-Fi Positioning to detect whether a user is stationary.
- In deep urban settings, WPS leverages faint GPS signals to consistently acquire location.