Federated Wireless, which made a name for itself preparing to serve as a Spectrum Access System (SAS) administrator for the 3.5 GHz Citizens Broadband Radio Service (CBRS) band, believes there are plenty of other spectrum bands that are ideal candidates for spectrum sharing.
Its suggestions are worth noting, because in the early days when the 3.5 GHz CBRS band was first being developed in the U.S., stakeholders said the unique spectrum sharing model could be applied to other bands should it prove successful. Whether it proves successful is yet to be seen; it’s poised for commercial lift-off in a portion of the band by year’s end, although by the CBRS Alliance’s count, it’s already established itself as a successful undertaking.
The FCC was directed by Congress to provide a report by Nov. 2 analyzing the results of the 2015 rule changes related to frequencies between 3550 and 3650 megahertz for the CBRS band, as well as to provide an analysis of proposals to identify additional spectrum bands that can be shared between incumbent uses and new licensed and unlicensed services. Congress also asked the FCC to identify at least 1 gigahertz between 6 GHz and 57 GHz for such use.
Toward that end, the FCC called for comments from interested stakeholders on the issues; comments were due Sept. 11, with reply comments due Sept. 26. The commission received a range of responses, but Federated specifically ticked off a list of multiple bands.
“The record in this proceeding and elsewhere demonstrates the myriad advantages of dynamic spectrum sharing technologies and dynamic access regimes,” Federated wrote in Sept. 26 reply comments (PDF) to the FCC. “The Commission should thus affirm in its report to Congress its commitment to studying and leveraging these technologies throughout the radiofrequency spectrum, including in the 3.7-4.2 GHz, 3.45-3.55 GHz, 3.1-3.45 GHz, 5.925 GHz-7.125 GHz, 37 GHz, 26 GHz, 70/80 GHz and 4.9 GHz bands.”
These are the same bands Federated identified in earlier comments (PDF), where it lists the current users of these bands and reasons they appear optimal for sharing.
Other entities submitted comments to the FCC about their 3.5 GHz experiences. Ruckus Wireless, an Arris company, identified a near-term opportunity (PDF) specifically for the 3450-3550 MHz range, which is currently being examined by NTIA and the Department of Defense. Ruckus also reiterated the need for more midband unlicensed spectrum to meet needs for services like Wi-Fi, unlicensed cellular (like LTE-LAA and 5G NR-U) and internet of things.
Interestingly, Federated suggested the 3.7-4.2 GHz band, also known as the C-Band, as one of the bands that the commission should explore for sharing. The FCC this past summer voted to seek further comment on ways to free up spectrum in that band, which is currently used by fixed satellite service and fixed service companies. It’s also a band that has attracted a lot of attention from the mobile industry, as it could serve as key mid-band spectrum for 5G.