02.10.2009 08:05 AM
DTV Signals Eyed for Boosting GPS Capability
A company that makes global positioning systems says the DTV signals could fill in for gaps in satellite coverage. Rosum, of Mountain View, Calif., said digital TV transmission could help GPS work in urban areas and even indoors, where satellite signals can’t reach, Ars Technica reports.
The key to the usefulness of DTV signals is that they are transmitted from fixed positions, contain a time stamp, and function at high power. Rosum find the compatibility particularly interesting for femtocells, a type of base station in cell phone networks similar to TV broadcast translators. Femtocells rely on GPS systems that in some cases require substantial antennae to work properly.
TV signals travel at lower frequencies than cell networks, so cross-interference wouldn’t be an issue. The infrastructure is also already in place, and more easily accessed than satellites circling the globe at 12,000 miles above sea level.