Hybrid Positioning System (XPS)
What is it?
XPS is a hybrid positioning engine that integrates the Wi-Fi Positioning System from Skyhook Wireless with other complementary location systems. The XPS engine provides a single location source to applications and services, while at the same time leveraging the strengths of each underlying system.
How does XPS work?
XPS is configured to integrate/synthesize the location output of the Wi-Fi Positioning System (WPS) and other positioning systems. It uses several different techniques to determine which source system is most reliable at any given moment. In some cases, XPS estimates the error of each of its source systems and favors the one with the highest degree of confidence at that particular moment. In other cases, the usage scenario or the confidence history of each source are leveraged. In every case, XPS uses this data to decide which source to favor or how to combine the various inputs into a superior overall calculation.
WPS can be combined with one or more complementary technologies, depending on the capabilities of the device and the needs of the applications.
WPS + GPS
These two systems are complementary, because they balance each otherís strengths and weaknesses. GPS works extremely well in open, sparsely populated areas where Wi-Fi coverage is thin or non-existent. Conversely, WPS performs best in congested population centers and indoors, two difficult environments for GPS due to line-of-sight and multi-path signal issues. Devices that have both GPS and Wi-Fi hardware can deliver the best overall combined performance by deploying XPS from Skyhook Wireless.
WPS + IP Location
IP address databases have been used for many years as a crude representation of location. IP addressing can only locate a user within an Internet service providerís service area, but its performance can be greatly improved by combining it with WPS. IP location techniques generally entail random sampling of a small set of IP addresses in order to validate location estimates. Because XPS can collect both an IP location and an accurate WPS location, it can not only improve the IP location scheme but also validate it in real time. The benefits include wider coverage for stationary Web applications and a zero-client deployment.
WPS + Cell Tower ID
Cell tower positioning has existed in several forms for more than a decade. Querying the network for the location of the tower providing wireless connectivity to a device at that moment provides the approximate location of the device. While not sufficient for most location-based services, this knowledge can be used to improve time-to-first-fix and expand overall coverage. XPS can combine cell ID and WPS to increase the location coverage for a wireless network without adding or modifying any hardware on the devices or the network.
WPS + WiMax
WiMax and Wi-Fi have many similarities, particularly in the area of base station identification. XPS can combine these two technologies, providing both the precision of WPS and the wider coverage area of WiMax.