TruePosition (News - Alert) Inc., a provider of wireless location solutions and a subsidiary of Liberty Media Corporation, has released results from indoor tests of its hybrid wireless location technology combining the Uplink Time Difference of Arrival (U-TDOA) and Assisted Global Positioning System (A-GPS) methods.

Officials with TruePosition said that of the four technologies tested, U-TDOA was the only one to have a 100 percent yield in both urban and suburban performance testing, with every test call generating corresponding location information.

“Tests conducted in San Francisco and in Wilmington, Del. and elsewhere clearly show that providing accurate location information to first responders when the call originates from a wireless phone indoors is an achievable goal,” said Steve Stuut, CEO, TruePosition, in a statement.

Stuut said that the combination of U-TDOA and A-GPS location technologies is an excellent solution for locating indoor 911 calls, or other situations where yield and accuracy are critical.

“U-TDOA and A-GPS technologies are both widely deployed in the U.S. today, and when combined, provide a solution that is not only technically superior, but also commercially viable and imminently available,” he said.

Stuut said that U-TDOA, currently deployed on AT&T’s (News - Alert) and T-Mobile’s networks, is already protecting the millions of AT&T and T-Mobile customers who dial 911 from their wireless phones, making it easier and faster for first responders to find them indoors; and can easily be paired with existing A-GPS capabilities in a hybrid solution

Earlier in April 2012, TruePosition and industry analyst firm Ovum (News - Alert) had announced a new white paper that details the importance of locating indoor 9-1-1 phone calls, which are made from cell phones.