The U.S. needs a mix of low, mid-range and high-band spectrum to meet the growing needs of wireless networks. Unlicensed spectrum, formerly considered a “junk band,” is especially needed, according to Ruckus Wireless Director of Regulatory Affairs and Network Standards Dave Wright.
Ruckus has installed WiFi and Wireless LAN networks in locations like Pittsburgh City Hall, the San Jose airport and convention center. The Sunnyvale, California-based company also develops LTE systems using the 3.5 GHz Citizens Broadband Radio Service. For in-building cell coverage, Ruckus combines multi-operator LTE access points with available CBRS spectrum.
Testifying before the House Communications and Technology Subcommittee this week, Wright cited a Quotient Associates report that modeled the amount of traffic that will need to be carried by WiFi in the years 2020 and 2025, and the amount of unlicensed spectrum that would be required. It forecasts a gap in the U.S. of between 220 to 628 MHz of unlicensed spectrum by 2020, and a gap of between 540 to 1588 MHz of unlicensed spectrum by 2025.
“Given the sharply increasing demands for unlicensed spectrum from WiFi, LTE, and IoT, and the specific gap noted just to meet our nation’s future WiFi needs, we strongly recommend expeditious action to identify additional mid-band spectrum that can be designated for unlicensed use, including spectrum where unlicensed operation would require mitigations to protect incumbent government or commercial services,” said Wright. Ruckus believes the 5925 to 7250 MHz range is one of the best candidate bands because of the characteristics of the incumbent services in the band, its proximity to the existing unlicensed bands between 5150 and 5825 MHz and the potential amount of spectrum that could be made available.
Europe is studying the technical feasibility of an unlicensed designation in this range and because of its unique spectral qualities, Ruckus believes equipment and services could be rapidly deployed. Ruckus urged lawmakers to support the efforts.
Ruckus also supports Coordinated Shared Spectrum, or CSS. CSS frameworks differ from unlicensed frameworks in that there is a coordination requirement to access the spectrum, whereas unlicensed access does not require coordination, Wright testified. CSS can be shared by several users with similar or different use cases – and can accommodate exclusive and permissive uses, whereas licensed frameworks allocate spectrum for exclusive use only.
CBRS is used on the 3.5 GHz band in the U.S. Industry organizations such as the Wireless Innovation Forum (WInnForum) and the CBRS Alliance have formed to commercialize the band; the WInnForum is developing technical specs while the CBRS Alliance focuses on optimizing LTE services for the CBRS band. Ruckus is a member of the CBRS Alliance, which began eight months ago with five other founding members; Google (Access Technologies), Federated Wireless, Intel, Nokia, and Qualcomm; Ruckus recommends that Congress and the FCC maintain the CSS framework and consider expanding it to other bands.
April 7, 2017
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