The National Cable & Telecommunications Association on Wednesday filed a report with the FCC aimed at persuading the commission to allow 100 MHz of spectrum in the 5 GHz U-NII-1 band to be used more broadly for WiFi, including the new gigabit WiFi standard 802.11ac. As the NCTA explains in a cover letter, the U-NII-1 spectrum band is currently limited to usage by satellite communications provider GlobalStar and by unlicensed users for low-power indoor usage only.
Globalstar has opposed changing the current restrictions on unlicensed use and has filed data it says shows that broader WiFi use in the U-NII band could cause harmful interference to its satellite service. According to the NCTA, the new data it has now filed disproves Globalstar’s arguments.
Those arguments were based on erroneous assumptions, the NCTA says in its letter. “Globalstar would have the commission believe that every single Wi-Fi access point in the United States will 1) operate outdoors, 2) simultaneously operate 24 hours a day, 3) only use the U-NII-1 band (essentially abandoning the 2.4 GHz and U-NII-3 bands), and 4) operate at a constant 30-degree elevation angle to the satellite with virtually no signal attenuation due to clutter,” the NCTA argues.
The restrictions on how unlicensed users could use the U-NII-1 band were set up at a time when stakeholders expected intensive use of the U-NII-1 band by multiple mobile satellite service (MSS) providers. But as the NCTA notes, “today Globalstar is the only MSS operator using the band. Every other company has gone bankrupt or uses different frequencies. And rather than the millions of customers that the FCC predicted many years ago, Globalstar uses the vast 100 MHz U-NII-1 band – over 1.5x more spectrum than the entire core 2.4 GHz Wi-Fi band – for four U.S. feeder link stations serving fewer than 85,000 duplex customers worldwide, only a subset of which are U.S.-based.”
Noting that traditional Wi-Fi bands have become very crowded, the NCTA argues that “the commission must not allow Globalstar to refuse to share and hoard 100 MHz of valuable spectrum in such an inefficient manner.”
In response to an inquiry from Telecompetitor, Globalstar said the NCTA study ignores important factors, “particularly the degradation of the Globalstar satellite downlink RF power and the analysis of the sensitivity of the Globalstar degradation to variation in WiFi deployment parameters.”
The NCTA analysis cannot be relied on, Globalstar said, noting that “it is impossible for NCTA or the FCC to ensure that Globalstar’s mobile satellite services will not suffer harmful interference if the unlimited, potentially ubiquitous outdoor deployment of U-NII-1 access points is permitted,” said Globalstar. “In this scenario, the number of outdoor devices ultimately deployed by ALLproviders of Wi-Fi services is unknown and could even far exceed current projections. ”
Globalstar also said that the NCTA analysis does not account for the possibility that Globalstar’s satellite service could be more heavily used in the future.
With the wireless industry expressing concern about an impending spectrum shortage, the NCTA’s arguments may receive a receptive ear at the FCC, which has become very interested in finding ways for different user groups to share spectrum. On the other hand, the FCC also is likely to be wary of approving the use of satellite spectrum for new purposes after global positioning service equipment experienced interference when the commission allowed Light Squared to begin deploying a terrestrial wireless network using satellite spectrum.
Cable operators have taken considerable interest in WiFi recently, apparently viewing it as one means of competing with telco competitors that operate both landline and wireless broadband networks.
To date gigabit WiFi has seen few deployments, as equipment supporting the 802.11ac standard is not widely available. One organization that has made an 802.11ac deployment is TechPad, a technology incubator based in Blacksburg, Virginia that allows local Wi-Fi users to connect to its network for free. The 802.11ac standard is backwards-compatible with earlier versions of the Wi-Fi standard.
As Telecompetitor reported previously, TechPad has had to ask local WiFi users to shut down their access points and use the free system in order to maximize performance of the new network.