The phase-out of analog TV broadcasting freed up frequency bands that can be used for wireless communications. Leti's new modem—presented at CES 2016—makes efficient use of this capacity to transmit data over long distances, both indoors and out. In open spaces, transmission distances can reach several kilometers.
"The main technical hurdle was to combine good spectral efficiency with low interference with adjacent bands. Generally, these two characteristics are mutually-exclusive," said a Leti researcher. Leti overcame this challenge, producing a demonstrator leveraging a new modulation technology whose performance exceeds what had previously been achieved using other technologies—effectively doubling the communication distances. The technology was selected for IEEE standard 1900.7, approved at the end of last year.
The TV White Space Modem could help close the digital divide by providing broadband internet access in poorly-served rural areas. It could also be useful in building communications networks for university campuses and similar sites, for instance, or in certain countries where DSL access is unavailable.