WASHINGTON—NAB told the FCC in comments filed Feb. 22 that it is “premature” to expand unlicensed access to the 6 GHz band and that easing restrictions would fail to protect licensed operators in the band, including TV broadcasters who use the band for electronic newsgathering (ENG).

The comments address a call from proponents of Remote LAN (RLAN) to relax Low Probability of Interception (LPI) rules to allow client-to-client communications if each C2C device is enabled with an authorizing signal transmitted from an access point.

“NAB has previously explained that ENG receivers are ‘hidden nodes’ because ENG receivers are passive and therefore cannot be detected by unlicensed devices (whether LPI access points or client devices),” NAB said in its comments.

PLUS: NAB: No Evidence for Increasing Unlicensed Power Limits in 6 GHz

The client-to-client proposal would exacerbate the problem because “the enabling access point may be located thousands of feet from a client device and will fail to detect a passive ENG receiver” that could be located near a transmitting client device, it said.

“Under these circumstances, it would be grossly premature to reverse the FCC’s previous conclusions regarding client-to-client communications,” the comments said.

NAB urged the agency to postpone any possible changes until after a record of “practical experience” has been established that demonstrates whether and under what conditions incumbent users experience interference, it said. 

However, if the FCC decides to loosen the rules, it should prevent the use of client-to-client devices in a portion of the 6 GHz band to create a safe harbor for ENG operations, NAB said.

In its comments, NAB also told the agency that it should not extend less protection to licensed 6 GHz users than it would for unlicensed operations if it followed recommendations from RLAN proponents. 

The laboratory division of the FCC’s Office of Engineering and Technology has specified that LPI access points must detect incumbents using a contention-based protocol (CBP) with a threshold level of -62 dBm/20 MHz, which corresponds to a power density of -75 dBm/MHz, the filing said.

However, RLAN proponents suggest a threshold for client-to-client devices of -99 dBm/MHz. “This is a difference of 24 dB, meaning that the threshold for protection of licensed devices would be over 250 times higher than the detection threshold required for the authorizing signal of client-to-client devices,” the filing said.

Further, the comments argued it is hard to “read this as anything other than a concession” that OET’s energy detection threshold for CBP is “insufficiently sensitive to detect other operations, whether licensed or unlicensed,” the comments said.

“Providing far greater protection to unlicensed devices than licensed devices would turn the entire premise of Part 15 of the commission’s rules on its head,” it said.

The comments are available online.  

WASHINGTON—If broadcasters are going to be sharing the 6 GHz band with unlicensed, low power indoor (LPI) devices, creating a “safe zone” to remove threats of interference is an action that the NAB believes should be taken.

This idea comes from an ex parte filed by the NAB after meetings with representatives from the FCC commissioners’ and chairman’s offices in regards to the proposed rule that would open up the entire 6 GHz spectrum band for unlicensed devices to operate in.

The 6 GHz band is primarily made up of broadcast ENG crews, and the NAB believes that granting permission to these unlicensed LPI devices to utilize the spectrum causes potential interference issues, a major disturbance particularly as broadcasters' ability to provide information to viewers has been heightened during the current coronavirus pandemic, the NAB argued.

The draft order does conclude that unlicensed devices can cause interference issues, but concludes the risk “to be insignificant.” This determination, the NAB claims, was done with no independent analysis, or at least none that was shared. The NAB also takes issue with an unclear definition of what the FCC deems as “insignificant interference.”

As a potential resolution, the NAB wants the FCC to not allow low-power devices to operate in U-NII-6, a part of the spectrum where broadcasters currently have the bulk of their authorized mobile operations, per NAB.

“This would allow the commission to make 1,100 MHz of spectrum available for unlicensed—a massive amount—while still preserving 100 MHz for broadcasters to continue to do their most important job without the threat of interference,” the NAB wrote.

Even if the FCC is set on freeing up 160 MHz channels for unlicensed devices, the NAB says it could do so for seven channels for 1,120 MHz and still leave 80 MHz at the top of the 6 GHz band not authorized for LPI. The NAB also says that it would be willing to consider alternative locations in the band.

Other points of argument in the NAB’s ex parte included how the FCC will be able to impose the “indoor-only” operation rule for LPIs; how a contention-based protocol does not work as intended with outdoor ENG operations; and for the FCC to convene a meeting to discuss and compare the analyses on the potential impact of opening the 6 GHz band.

“NAB broadcasters across the country and their viewers cannot rely upon mere judgement rather than independent analysis of a highly technical issue,” the ex parte reads. “As a result, we believe that allowing a safe zone of less than 7% of the overall band where LPI cannot occur at this time at least provides both the commission and broadcasters some protection as the band is forever altered.”

The full ex parte from NAB is available online. 

WASHINGTON—FCC Chairman Ajit Pai has issued official draft rules that would allow unlicensed devices to have access to operate in the entire 6 GHz band, which includes 1,200 MHz of spectrum.

That spectrum is primarily used by broadcast ENG users and utility companies. If this proposal were enacted, the incumbent users would share the spectrum with unlicensed devices that use the internet for operation. While broadcasters have reportedly been open to the idea of sharing some of the 6 GHz band, their chief concern is over the potential interference that could come from unlicensed devices.

In the official announcement of the proposal, Pai says that licensed services operating in the 6 GHz band would be protected so that both licensed and unlicensed services “could thrive throughout the band.” 

If adopted, the draft Report and Order authorizes two different types of unlicensed operations. The first would be standard-power in 850 MHz of the band, while indoor low-power operations could operate over the full 1,200 MHz. It claims that an automated frequency coordination system would prevent standard power access points from operating where there could be interference to incumbent services.

“By doing this, we would effectively increase the amount of spectrum available for Wi-Fi almost by a factor of five,” Pai said in the official announcement. “This would be a huge benefit to consumers and innovators across the nation. It would be another step toward increasing the capacity of our country’s networks. And it would help advance even further our leadership in next-generation wireless technologies, including 5G.”

In February, a group of conservative leaders wrote to Chairman Pai calling for the opening of the 6 GHz band. Others, including the NAB’s Patrick McFadden, have questioned whether there is a true need for unlicensed devices to operate in the 6 GHz band.

“The last few weeks of lifeline coronavirus coverage by local TV stations have made crystal clear the value of the 6 GHz band to broadcasters and the viewers we serve,” said Dennis Wharton, NAB's executive vice president of communications, in response to the proposal. “If broadcasters are to continue providing news coverage that is trusted in a crisis, we need spectrum to provide that service.

“We have previously witnessed the negative impact Wi-Fi operations have caused to spectrum broadcasters use to cover breaking news. Opening the entire 6 GHz band to unlicensed use without strong safeguards risk locking the FCC into a mistake it cannot correct. We look forward to engaging with the FCC to discuss potential solutions, including appropriate power levels, methods for redistricting indoor-only operations and other options to protect broadcaster uses.”

A Further Notice of Proposed Rulemaking has also been issued that proposes to permit very low-power devices to operate across the 6 GHz band to support high data rate applications. The FNPRM seeks comment on making a contiguous 1,200 MHz block of spectrum available for the development of new high-speed, short-range devices and on power levels and other technical and operational measures to avoid causing interference to incumbent services.

The draft rules are expected to be voted on during the FCC’s Open Meeting on April 23.

Saying Nominet, the FCC's white spaces database administrator, had incorrect channel info for at least a couple of hundred TV stations, the National Association of Broadcasters has asked the FCC not to make that database available until the problems are fixed.

The database identifies channels in use, which unlicensed devices authorized to use the so-called white spaces between TV stations are then supposed to steer clear of to avoid interference. So, correctly identifying where stations are operating is crucial to make sure unlicensed use is not interfering with licensed TV broadcasts.

NAB also says Nominet has not been in compliance with FCC rules, raising further questions about its reliability.

Nominet told the FCC back in August that, contrary to NAB's assertions, it "operates as required by both the FCC’s rules and the various private technical standards relating to WSDB operation. It said that its testing had revealed a "small number of items to be addressed," which were resolved.

 But NAB says that Nominet can't insure it is getting the right info from the FCC, and it is troubling the FCC's process for vetting database administrators could not catch fundamental errors. 

"Absent NAB’s expenditure of thousands of dollars to commission an evaluation of Nominet’s data, these errors would have gone unnoticed and uncorrected, and would inevitably have resulted in harmful interference to licensed operations."

NAB did sound a note of optimism. It said that if was confident Nominet would address the issues, but that the database should not be in public use until it does, and that the FCC should take two more steps: 1) Review Nominet and only approve it when the FCC is 100% satisfied it is accurate, and 2) revise the process so NAB or others don't have to spend thousands of dollars insuring the commission approach actually does protect them, which in this case it did not.

WASHINGTON—How about ruling on white-space device geolocation already, the broadcast lobby told regulators recently. Representatives from the National Association of Broadcasters met with staff members of the Federal Communications Commission to discuss the operation of unlicensed devices on unoccupied TV channels, referred to in this case as “white spaces.”

“The commission should either adopt and enforce effective rules that will allow TVWS devices to coexist with licensed operations, or it should eliminate or suspend TVWS operations,” the NAB said in an ex parte filing documenting the Nov. 16 meeting between the NAB team and commission staff.

The problem, according to the NAB, is that the FCC’s database system for keeping track of white-space devices doesn’t work, so in the event these devices cause interference to TV signals, broadcasters won’t be able to track them down. The extent of the problem was such that in March of 2015, the NAB petitioned the commission to shut down the database system because, “at various points, more than one-third of fixed TV band devices in the database contained patently inaccurate location information, including multiple devices registered in the middle of empty fields, or to a single family home, and some even registered in foreign countries,” the NAB petition said.

NAB thought the issue was hashed out in July of 2015, when it struck up an agreement with white-space device makers to incorporate automatic geolocation in the devices. (See “NAB and White Space Device Makers Agree on Geolocation,” July 22, 2015) The commission responded seven months later with an Order to clean up the databases rather than shut them down, and an accompanying Notice of Proposed Rulemaking on the integration of geolocation technology.

Since then, le crickets.

“Nearly nine months have passed since the released of that NPRM, yet commission staff have told NAB they do not believe an order will be forthcoming until the next administration,” the NAB’s recent ex parte filingstated.

Further, a previous amendment requiring updated channel availability information to be pushed to white-space devices as of Sept. 23, 2016, is a paper tiger, the NAB said.

“There are currently no industry standards for implementing the push notification requirement and, to NAB’s knowledge, TVWS database administrators and TVWS device manufacturers have taken no steps to comply with this requirement,” the ex parte filingstated.

If the commission hasn’t acted because so few white-space devices have been deployed, then it should scrap them altogether, the NAB folks suggested.

Also see TV Technology’s previous coverage of white-space devices…

July 22, 2015
NAB and White Space Device Makers Agree on Geolocation

May 4, 2015
NAB to FCC: TV Licensees Should Trump White Space Devices

March 19, 2015
NAB Petitions FCC to Shut Down White Space Database

March 19, 2015
Google White Space Database Registered Fixed Devices

January 15, 2014
FCC Certifies Carlson Wireless TV White Space Radio

November 14, 2013
FCC Certifies Adaptrum Technology With Google TV White Space Database

September 16, 2013
FCC Grants Adjacent-Channel Waiver for Meld White Space Device

March 4, 2013
White Space Databases Go Live Nationwide

January 23, 2013
Tokyo Group Unveils Regional TV White Space Prototype

December 6, 2012
White Space Databases to Go Live Next Month

October 18, 2012
White Space Wi-Fi Draft Standard Prototype Developed

June 4, 2012
Theater and Sports Groups Drop Request for White Space Rules Review

May 3, 2012
NAB Drops Court Challenge of White Spaces

March 27, 2012
Telcordia Gets Cleared to Manage White Spaces

February 29, 2012
Key Bridge Launches Preliminary White Space Portal

November 24, 2008
White Spaces Deal is Done

January 31, 2012
White Spaces: Telcordia Says It Can Find Them

December 5, 2011
FCC To Commence Second White Space Database Trial Wednesday

November 10, 2011
FCC Seeks Comment on Spectrum Bridge White Space Trial

September 14, 2011
Spectrum Bridge Is First of 10 To Test White Space Database

July 27, 2011
IEEE Publishes White Space Standard for Broadband

June 29, 2011
Microsoft White Space Partner Neul Raises $12.8 Million

June 27, 2011
Microsoft Angles for Lighter U.S. White Space Rules with U.K. Trial

June 22, 2011
Microsoft Nudges FCC to Wrap White Spaces

May 2, 2011
Microsoft Wants to Manage TV White Spaces

January 27, 2011
TV White Space Database Managers Named

December 6, 2010
White Space Rules Go Into Effect Jan. 5, 2011

September 27, 2010
SPECIAL REPORT: FCC White Space Rules

September 27, 2010
Nine Vie to Manage White Space Database

September 23, 2010
FCC Eliminates Spectrum Sensing for White Space Devices

September 16, 2010
Carlin Could Curse in TV White Spaces

September 15, 2010
Ohio Hospital Launches White Space Broadband Trial

September 8, 2010
FCC to Issue Second White Spaces Order

August 18, 2010
Broadcasters Urge FCC to Retain White Space Spectrum-Sensing Requirement

August 2, 2010
FCC Denies MSTV’s Request for White Spaces Documents

June 23, 2010
Google Supports White Space Smart Grid Trial

April 22, 2010
Wireless Group Asks FCC to Relax White Space Rules

April 21, 2010
Input Sought for White Spaces Book

March 26, 2010
TV White Space Experimental Licenses Granted

February 24, 2010
Wilmington Tests WiFi in White Spaces

January 4, 2010
White Space Database Manager Proposals Due

November 18, 2009
British Regulator Open White Spaces

October 22, 2009
Virginia Town Exemplifies White Space Usage

October 12, 2009
FCC Grants Microsoft White Space Licenses

March 3, 2009
Broadcasters Asks Court to Nix FCC White Space Order

February 23, 2009
White Space Locater Launched