Skyhook Wireless launches Wi-Fi-based positioning system: The company has a new name, but CEO Ted Morgan said in an interview last week that Skyhook's intent in the same: using the location of Wi-Fi access points to pinpoint urban and suburban locations just as a GPS (global positioning satellite) receiver would. (You may remember Skyhook as Quarterscope back when they won a cellular industry award in spring 2004.)

Skyhook has assembled a database of information about 1.5 million access points across 25 major cities in the U.S. by driving every street in every city. Their software records multiple data points per sample for directionality. Fire up their software on a laptop, and it compares the Wi-Fi information it sees with what's in the Skyhook database, popping out a latitude and longitude within 20 to 40 meters.

The APs they rely on aren't per se public: they're the Wi-Fi gateways operated in homes and businesses that spew their unique identifiers and signal characteristics far beyond a home or an office building. Skyhook tethers itself to the high number of fixed-location gateways to deliver urban GPS-like reliability with lesser certainty as one reaches into less-dense suburbs.

Morgan said that in most cities, there are "8 to 15 APs at any given point to use." The baseline scan they performed is dynamically updated based on client software, too. If a number of APs can be detected at a certain location, new APs or ones that don't conform to the data can be added and updated. This happens constantly. "The user environment itself is maintaining and updating" the location database, Morgan said. This means that shifts over time won't affect overall accuracy and new information will supplement existing baselines. The company also has contracts with delivery firms they haven't revealed to perform ongoing scans.

Skyhook's first announced partner is CyberAngel Security Solutions, which operates a laptop recovery system. The CyberAngel software already uses Internet protocol address tracing and other tools once a laptop is powered up. Add in GPS-like location awareness, and CyberAngel may be able to call the police with a street address to find a missing device.

Morgan stressed that Skyhook sees itself, as it has throughout its two-year development process, as a complement to GPS, providing the same kind of information in areas where GPS works less reliably or where the cost of a GPS receiver is prohibitive for the purpose.

The company has a trial in Boston of a fleet of 50 vehicles in which both GPS and Skyhook software is in use to better provide continuous location and direction information. It's also easy to see this as an add-on to car navigation systems in which Wi-Fi can be used to transfer new information to cars along with its use as a sensor, or a car could even be equipped with a 3G cell uplink that's part of the overall system.

The Skyhook software requires Internet access to reach the backend database, but Skyhook will also have versions that compress a kind of signature of its AP information into about 7 megabytes for more lightweight devices. 7 MB used to seem enormous, but cell phones are shipping with gigabyte hard drives and Webcams, so it's not as big a bar to entry as it used to be.

Morgan also sees a use for his system with voice over IP systems that now face E911 requirements. He says that Skyhook offers the only reasonable way for a mobile soft or hard VoIP phone to provide continuous location information.

Morgan hopes that location-awareness becomes a routine tool that gets integrated into software and Internet applications. Because so much of the Internet has become increasingly focused on local content and targeted advertising, it's of better utility to a user and better value for an advertiser to know exactly where someone is--but, of course, only if they want to reveal that.