With unlicensed Wi-Fi spectrum becoming increasingly crowded, equipment manufacturers and service providers are pushing to make more spectrum available on an unlicensed basis – and while substantial progress has been made on that front, more work remains, as a couple of investor conference calls recently conducted by Bernstein Research illustrate.
On one of the calls Paul Margie, a partner at D.C. law firm Harris, Wiltshire & Grannis, shed light on several open issues – including how much unlicensed spectrum is likely to be made available through the voluntary TV broadcast spectrum auction in the 600 MHz band, the three-tier plan that the FCC has proposed for unlicensed spectrum in the 3.5 GHz band, and Globalstar’s proposal for a private Wi-Fi network in the 2.4 GHz band. As Margie explained, those are three of the four bands – including the 5 GHz band – where additional spectrum could be made available to support WiFi or similar offerings.
Telecompetitor would like to thank the telecom financial analysts at Bernstein for sharing transcripts of the call with Margie and from a call with Jay Monroe, chairman and CEO of Globalstar.
The 600 MHz Band
Although most of the spectrum expected to be freed up through the voluntary auction of TV broadcast spectrum will be made available on a licensed basis, some unlicensed spectrum also is expected to be made available.
Details are still being resolved at the FCC but Margie expects three 6 MHz channels to be freed up nationwide for unlicensed use. This includes 6 MHz in the 11 MHz duplex gap that will be established between downstream and upstream channels; two 3 MHz guard bands – one above and one below Channel 37, which is reserved for medical telemetry and radio astronomy; and a 6 MHz guard band adjacent to the lowest frequency licensed channel in the 600 MHz band. The exact location of that channel and the one in the duplex gap likely will vary from market to market, depending on how many broadcasters relinquish spectrum.
Margie expects to see equipment conforming to the 802.11af standard used in the 600 MHz band because that standard is based on 6 MHz channels.
The 3.5 GHz Band
When the FCC proposed rules for the 3.5 GHz band earlier this year, the commission said it envisioned the spectrum being used for “general consumer use, carrier-grade small cell deployments, fixed wireless broadband services and other innovative uses.”
Plans aren’t finalized yet but Margie outlined the three-tier plan that the commission has proposed for the band, where spectrum will be shared with existing users of the band including navy ships. Those users would comprise the first tier and would be able to interfere with others’ communications, but other communications would not be allowed to interfere with theirs. The navy’s usage is primarily along the coasts, but Margie noted that the navy has not yet confirmed how much of the country it will consider off limits.
The second tier would be a priority access tier. As Margie explained, what that means is that “you would have the exclusive right to some number of channels for some geography. If nobody else wanted it, you would get it for free.” If multiple parties wanted the same spectrum, there would be a “light auction” to determine the winner, he said.
Wireless operators are very interested in using the spectrum to provide extra capacity in high-usage areas, Margie noted.
The third tier would work like Wi-Fi unlicensed bands, Margie said, but he didn’t discuss any standards efforts or manufacturer plans involving equipment for the 3.5 GHz band.
The 2.4 GHz Band
Another Wi-Fi related issue still pending at the FCC involves a proposal from Globalstar. The satellite operator holds a license for spectrum in the 2.4 GHz band which happens to be adjacent to unlicensed spectrum that is widely used for Wi-Fi – and as Monroe explained, that means that existing Wi-Fi equipment, including carrier-deployed access points, could be upgraded to support communications in that band.
Globalstar has asked the FCC for permission to use its 2.4 GHz holdings, originally intended for satellite use, to support a private Wi-Fi offering dubbed terrestrial low power service (TLPS) that would be less congested and therefore would provide better performance than today’s offerings. Monroe didn’t provide details about how Globalstar would make money on the Bernstein call, other than noting that carriers, cable companies and tower companies all might be interested in TLPS. But a different Globalstar executive previously told Telecompetitor that the company was considering a subscription or licensing model.
Margie said he believes the FCC will approve Globalstar’s proposal if engineers determine that TLPS won’t interfere with existing Wi-Fi devices. He also noted that the FCC would need to determine whether Globalstar would be treated like any other Wi-Fi provider or whether it would have any special protections against interference.
The 5 GHz Band
The FCC earlier this year freed up 100 MHz of spectrum in the 5 GHz band for unlicensed use, and when used in combination with an additional 100 MHz of spectrum in the band that was previously available, it is now feasible to support data communications at speeds of up to 1 Gbps, Margie explained.
The standard for gigabit Wi-Fi is known as 802.11ac and equipment supporting that standard is already available. Margie noted that it requires two 80 MHz channels.
