The FCC is placing bets for some TV broadcasters. After all the wireless carriers ante in on the reverse-spectrum auction table, will the hoped-for win-win cover all (or 80% of) channel relocation costs? Is a bet like this legal in Las Vegas? Will channel forty something in South Podunk bring a buck? Please Stand By. 

The auction doesn’t open for another nine months. The only sure bet is that a monumental crescendo of hype has no end in clear sight. In the words of most TV news promos, this is breaking news and a developing story. The difference from most breaking news is that the conclusion is years away.

Some but not all FCC licensed TV stations operating on 600 MHz band channels will become unvoluntary players. A few other stations might be affected with channel sharing or perhaps moving to a new channel to accommodate new assignments.

Who knows? Nobody. The only action TV stations and broadcast engineers can take right now is to follow the action and develop a what-if Plan B. The unanswerable question until the reverse auction is complete is which stations will be affected and which won’t?

Auction update

On 6 August 2015, the FCC adopted a Report and Order that updates Part 15 to address the demand and encourage innovation in unlicensed use in the 600 MHz band. The new rules are "designed to allow for more robust unlicensed use and to promote spectral efficiency in the 600 MHz band." The new rules will “permit unlicensed fixed and personal/portable white space devices and unlicensed wireless microphones to use channels in the 600 MHz and television broadcast bands while continuing to protect television and other licensed services from harmful interference.”

Right now, Part 15 rules let unlicensed devices to operate on unused TV channels in the so-called “white space” spectrum. It is a common frequency choice for wireless mics. Following the coming incentive auction, there could be fewer white space frequencies in the TV band available for unlicensed use, depending on the market.

The FCC says the new rules “Permit more robust and efficient operation of fixed and personal/portable white space devices in television broadcast bands without increasing the risk of interference to broadcast services.” Not so fast, NAB and AT&T said in their own carefully chosen words.

Duplex gaps

The primary issue is duplex gaps. The duplex gap is the spectrum between the licensed uplink and downlink channels in the 600 MHz band. The NAB and AT&T say unlicensed transmissions in the duplex gap create the potential for interference in the adjacent licensed allocations.

In a recent statement, AT&T claims "The wireless industry -- the very entities that are being asked to spend billions of dollars to make the auction a success -- conducted and submitted testing that conclusively demonstrated this potential [for interference]." The NAB, is similarly troubled about interference, saying the auction plan is "destined for decades of interference disputes."

CTIA, otherwise known as The Wireless Association and originally known as the Cellular Telephone Industries Association, has expressed similar concerns. CTIA and its members commissioned telecommunications engineering consultant V-COMM to perform testing on commercial mobile broadband devices to assess the impact of unlicensed white spaces devices and wireless microphones operating in the 600 MHz duplex gap and guard bands.

Accurate results?

In a 1 July 2015 Electronic Filing, CTIA said “The real-world testing results of V-COMM which demonstrate that the Commission’s proposed technical rules for unlicensed operations in the 600 MHz guard bands and duplex gap would result in harmful interference to licensed services in violation of the Spectrum Act.”

The Spectrum Act states the “Commission may not permit any use of a guard band that the Commission determines would cause harmful interference to licensed services.” In its Overview section of the Electronic Filing, CTIA says “Therefore, in accordance with the Spectrum Act, unlicensed operations in the 600 MHz guard band and duplex gap can only be introduced through a regulatory framework that ensures that such operations do not raise harmful interference concerns. The CTIA Electronic Filing is posted here..

FCC Commissioner Ajit Pai‘s statement noted that while he did vote to approve the rules, he held some reservations about interference concerns. He said "Indeed, the record shows that even a 5 percent loss of spectrum capacity due to interference from guard band operations will lower spectrum values by 9 percent. A 20 percent impairment will lower them by 43 percent," he wrote in his statement following the vote.

The bettors

At the betting table are Wi-Fi supporters like the Wi-Fi Alliance, WiFiForward and Google who consistently push the FCC to release more spectrum for unlicensed use. Google is one of several companies to manage a database for TV white spaces (TVWS). Google urges the FCC to find spectrum for unlicensed use.

In a recent FCC filing, Google said "Google and other TVWS database operators and device manufacturers are working collaboratively with Commission staff and NAB to further refine TVWS processes and address any remaining concerns." The company went on to say "For example, Google supports the efforts of NAB and TVWS equipment manufacturers to minimise and/or eliminate human involvement for location determination on TVWS equipment. Google is also an active participant in the White Space Database Administrator Group's work with the FCC to harmonize database records and improve data hygiene."

According to Law360.com, “Google said the auction team’s recommendation of relocating broadcasters into one of those three specified set-asides, the duplex gap, could hinder innovation.” Google went on to tell the agency “it should find alternative low-band spectrum for unlicensed use if it decides to move broadcasters into the duplex gap in certain markets.”

No big deal?

On 21 July 2015, the NAB proposed the agency limit the relocation of television stations to the duplex gap to six of the 210 television markets. Previously, the NAB and other entities called existing TV white space operations haphazard and unorganized.

The FCC's new 600 MHz incentive auction rules for unlicensed operations will provide technical parameters for "fixed and personal/portable white space devices to operate in the 600 MHz band, including the duplex gap and guard bands, and channel 37 on a shared non-interference basis with medical telemetry and radio astronomy." The FCC said it will allow sharing of spectrum between white space devices and wireless mics.

The FCC also said it will expand the location and frequency information in white space databases and institute "transition periods" for the certification, manufacturing and marketing of white space devices and wireless microphones that comply with new rules.

Nothing is etched in stone. The exciting action is just beginning.

See previous article on the spectrum auction here.