The FCC's proposal to open up more of the 5 GHz band for use by unlicensed devices continues to draw criticism and generate debate in multiple corners, as supporters of the commission's plan square off against critics that are concerned about the proposal's impact on vehicle-to-vehicle (V2V) communications and wireless Internet service providers (WISPs).
Wi-Fi advocates have long sought the availability of more frequencies for unlicensed operation in the 5 GHz band. In response, on Feb. 20, 2014, the FCC issued a Notice of Proposed Rulemaking (NPRM) to amend Part 15 of its rules governing the operation of Unlicensed National Information Infrastructure (U-NII) devices in the 5 GHz band, specifically 5150-5350 GHz and 5470-5825 GHz. It also sought comments on making available an additional 195 megahertz of spectrum in the 5350-5470 GHz and 5850-5925 GHz bands for U-NII use.
Proposed rules changes for the U-NII-3 band–5.725-5.850 MHz–are drawing heavy criticism from V2V and WISP advocates, which have filed petitions for reconsideration.
The National Cable and Telecommunications Association (NCTA) and Telecommunications Industry Association (TIA) recently filed comments opposing a petition for partial reconsideration of the FCC's 5 GHz plan that was submitted in May by the Association of Global Automakers. The automakers are concerned that allowing unlicensed device operations in spectrum up to 5850 MHz will cause interference with the adjacent U-NII-4 spectrum, also called the 5.9 GHz band, which includes frequencies at 5850-5925 MHz.
The FCC previously allocated use of the 5.9 GHz spectrum to Dedicated Short Range Communications Service (DSRC) systems and the U.S. Department of Transportation's Intelligent Transportation Systems effort, which is working on V2V communications to prevent or reduce the impacts of car crashes. The NCTA and TIA both contend that new FCC requirements that digitally modulated U-NII devices operate under out-of-band emissions (OOBE) rules that are tighter than were previously in place will protect DSRC systems.
The TIA also insists that unlicensed operations are possible even within the 5.9 GHz band if affected parties cooperate. "To that end, TIA has been strongly supporting the recently-introduced bi-partisan and bi-cameral 'Wi-Fi Innovation Act' which would advance testing work at NTIA and the FCC," the group stated.
The Association of Global Automakers has also previously expressed concerns about that legislation, which was introduced in June by senators Marco Rubio (R-Fla.) and Cory Booker (D-N.J.). A companion bill was unveiled in July by four House lawmakers. The bills direct the FCC to conduct tests within the 5.9 GHz band to see if more can be opened up for unlicensed Wi-Fi without interfering with current users.
The Fixed Wireless Communications Coalition is also seeking dismissal or denial of the petition filed by the Association of Global Automakers. However, the FWCC said it supports three other petitions for reconsideration–filed by the Wireless Internet Service Providers Association, Jab Wireless and Cambium networks–that seek reinstatement of earlier, less stringent OOBE limits for the U-NII-3 band.
Cal.net also protested the proposed OOBE limits, saying the company is "gravely concerned about the forthcoming changes to the 5725-5850 MHz band." The WISP, which serves certain rural regions of northern California, said the combined effect of narrowing the band and the lowering power levels could result in 700 to 1,000 of its subscribers' losing service, resulting in a revenue hit to the company of $40,000 to $60,000 per month.
"Although we could absorb that loss of revenue by laying off a large contingent of our employees, that would be a great disservice to our community–not just because of job losses for a few, but more importantly because of Internet service losses for hundreds of residents," the carrier added. "Thus, we would have no choice but to reengineer our wireless network, at a cost of $1.2 million to $1.6 million, to accommodate these changes, so that we can ensure our community retains its Internet service."
Likewise, Motorola Solutions said it supports petitioners requesting reconsideration of the revised OOBE limits. It said more stringent OOBE limits proposed by the FCC would have significant negative consequences for WISPs "without concomitant public interest benefits."
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