Hybrid Positioning Technology with Broadcast TV Signal and GPS

I listened Todd Young talk at last summer’s Where 2.0 conference. Todd is the Director of Product and Business Development at Rosum Corporation, a company that has developed a way to use unmodified broadcast TV signals for positioning in these places where GPS often fails (my previous post on this). These signals penetrate buildings and are already available worldwide. In fact, they have an hybrid solution that uses TV signals and GPS. Their RTMM device uses multilateration of TV signals and a centralized server when GPS fails to get a fix.

The main advantages of positioning with TV signals is that if works indoors and the infrastructure is already in place. The (major) drawbacks it that it relies on a centralized location server. It means:

• the need of coverage by another wireless technology
• there is the cost (price) of data transfer to calculate a position
• privacy issue in having a centralized server calculating a position
• manage a database of a gazillion antennas (well probably a bit less in the US). In the US, the FCC probably has an open database, it might not be the case in Europe/Asia.
• it relies on broadcast television, while the US and european markets are moving to wired television.

no 3D positioning, the elevation can very hardly be calculated

Currently, their first generation device is “unusable”. It is too big to be integrated into mobile devices like mobile phones. Todd mentioned that we have to wait for their engineers to get into the 4th generation in order that have that happening.

Todd mentioned that Rosum’s customers ask for security and live saving applications (clearing thinking E911 and police/firefighter location here) and even tracking high risk parolees. It does not come into a surprised that Rosum is partially founded by the CIA Not really surprising the CIA-backed venture firm In-Q-Tel

Rosum’s system would come really interesting for a broader market if it did not have to rely on a centralized location server. They have a mention on the technological feasibility on their web site
Note that location could be determined autonomously without a centralized location server at the RTMM under the following situations:

• TV signals were all synchronized to a common clock
• Timing information for the TV clocks could be provided over-the-air as a part of the TV signal.