Location-based services aren't just GPS-based anymore. Take Skyhook Wireless, which has launched version 2.0 of its XPS Hybrid Positioning. The system is "hybrid" in that it uses signals from Wi-Fi access points, GPS satellites, and cell towers to collectively find the quickest, most precise, and most consistent overall location data to send to users' handsets.Unlike assisted-GPS, or A-GPS, which simply adds cell tower triangulation data to GPS data to provide location information, the XPS positioning system uses complex algorithms to determine the strongest signal from cell tower data, GPS signals, or Wi-Fi access point data.

Skyhook hopes to make the XPS platform available to device and chip manufacturers for an "at-the-source" attempt at vast location-aware deployment. The currently deployed first-gen Skyhook system is already in use in millions of devices worldwide.

In downtown urban environments and indoors, GPS loses its quality and consistency, while cell tower triangulation is far less accurate when compared to GPS. Wi-Fi positioning is the only suitable solution in this situation because of the high saturation of access points and the likeliness that you'll find a signal.

On the other hand, in wide-open rural environments, cell tower and W-Fi-based positioning can become unreliable and inaccurate, while GPS is the suitable location technology. Having a combination of all three systems, and being able to determine and utilize the strongest and most accurate positioning, is the key to the XPS system and widespread location-based-services as a whole.

Responsiveness is critical is consumer applications, and mobile positioning is no different. If a consumer is using a location-based service, that location data has to be available to the application instantly. Consumers won't wait 20 to 60 seconds to get a good fix on their location. Skyhook claims its XPS system can deliver a full GPS/Wi-Fi/cellular hybrid location in just 4 seconds from a complete cold start, compared with 30 to 60 seconds with just A-GPS.

The addition of cell tower positioning increases availability so that users always get a location calculation regardless of environment. Additionally, XPS claims to deliver five to 10 times better power conservation than A-GPS alone because of the unequaled acquisition time and accuracy in XPS.

The XPS system is the closest thing available to a complete, all-in-one mobile-positioning solution. If the company succeeds in getting its system into the hands of device manufacturers, chipmakers, and carriers, the future of location-based-services and mobile applications will be very bright.