Memory Lane: A broadband alternative heats up
In September of 1948, the average high temperature in Washington, D.C., was 79.8 degrees Fahrenheit, off just a tick from the historical average of 80.7. So it’s ironic that September would go down in history as the month of the Big Freeze – at least in the television business.
The freeze referred to an FCC decision to halt spectrum allocations for television broadcasting. At the time, 108 stations were on the air, and demand was mounting for permission to beam moving pictures and sound over frequencies within the 50 to 294 MHz range, a prized swath notable for its ability to convey signals over wide ranges and to penetrate walls.
The FCC faced industry pressure to open up assignments on request rather than to create a structured approach that would unify channels across the country. It was inflection point whose resolution would determine how a powerful medium would grow up, and the FCC realized the gravity of the moment. In September, the commission ordered a freeze on allocations for the next six months as it sorted through conflicting ideas for stewarding the nation’s television system.
Nicknamed the Freeze of 1948, the moratorium would extend for nearly four years as the commission wrestled with a changing technology environment – color TV among the new influences – and as the Korean War diverted the government’s attention. In April 1952, the FCC finally released its Sixth Report and Order, spelling out a national scheme for allocating frequencies for television broadcasting and painstakingly explaining its reasoning.
“It has been urged in this proceeding that as a matter of policy we should abandon the concept of a nationwide table of channel assignments and permit applicants from any community to apply for the use of any channels provided certain general engineering criteria were met,” the Report and Order said. “Upon careful consideration of the record in this proceeding we are convinced that the public interest requires our adherence to the concept of a table of channel assignments as the most effective method for assuring a fair distribution of television service throughout this country.”
Thus was established the still-prevailing system for TV broadcasting in the U.S. Hallmarks included frequency blocks of 6 MHz for television signals, geographic exclusivity of assigned frequencies, provisions for guarding against interference and the reservation of certain frequencies for educational television.
This cornerstone system, with adjustments over time for more frequencies and digital transmission technologies, has informed the broader telecommunications environment in ways the FCC could not have envisioned. The foundation for the cable industry’s breakthrough high-speed Internet specification, DOCSIS, has leaned mightily on the FCC’s channel allocation scheme for broadcast television by stuffing Internet packets into the same 6 MHz vessels that originally were sanctioned for over-the-air television. Only now, with the latest DOCSIS 3.1 iteration, does the specification abandon the notion of organizing bandwidth in 6 MHz chunks, instead inviting cable providers to assign whatever swaths of spectrum they choose for Internet traffic.
But the broadband Internet firmament will continue to borrow from the television past. In particular, an emerging approach for delivering high-speed Internet services wirelessly, known colloquially as TV White Space, mines familiar terrain. TV White Space implementations fetch unused slivers of spectrum originally assigned for TV broadcasts and run IP traffic across them, taking advantage of the same range and propagation qualities that have long benefitted broadcasters – hence the nickname “Super Wi-Fi.” The big difference is that the FCC treats TV White Spaces as unlicensed spectrum, meaning anyone can rig up a broadband IP network over these unused frequencies so long as they keep their signals from interfering with broadcasters’ assigned channels. (Database tables maintained by Google and others keep watch on which frequencies are available where.)
The FCC’s forthcoming auction of prized television spectrum complicates the picture for TV White Space a bit, giving would-be investors the shakes. But implementations are rising in the U.S. and elsewhere, with some backed by tech titans like Microsoft and Google.
In the fall of 1948, when the FCC took a breather to think carefully about how to orchestrate the development of TV broadcasting, the commission couldn’t have dreamed it would be influencing the development of broadband Internet access. But the decisions it made have done just that. Sixty-some years later, a scheme for over-the-air television might just change the landscape for high-speed Internet delivery, potentially helping to close broadband availability gaps for unserved communities. Score one for the freeze.