Spectrum sharing was a theme at the International Symposium on Advanced Radio Technologies (ISART 2015) in Boulder, Colo., last week, and Google (NASDAQ: GOOG) shared what it's been doing to enable the FCC's spectrum-sharing vision in the 3.5 GHz band.
According RCR Wireless News, Google demonstrated the third version of the Spectrum Access System (SAS) it has built, which includes software running on Google infrastructure that is capable of dynamically managing the relationships among three proposed tiers of users at 3.5 GHz: federal and nonfederal incumbents, Priority Access Licensees and General Authorized Access users.
Google consistently has supported the use of interconnected SASs to manage coexistence in the 3.55 GHz bands. It has been running several wireless transmission sites at 3.5 GHz to develop and test the technology, and it has demonstrated its prototype SAS at previous FCC workshops and events.
The commission noted in its Report and Order released in April that it wasn't taking a position on whether Google's prototype SAS would actually satisfy all the requirements set forth in its order. The idea is that Google would be one of multiple SAS providers for 3.5 GHz, creating an ecosystem and taking Google into software for the management of wireless spectrum systems that leverage the cloud and fast processing speeds.
The company began its work on a SAS, in part to prove that it could be built and function, and because telecom industry skepticism about whether a SAS would actually be viable could only be answered if one was built, Preston Marshall, principal wireless architect for Google Access, said, according to the RCR report.
Marshall said that Google's current SAS can handle 10 million devices under management, although it estimates that only about 1 million to 5 million devices would end up receiving protection through a SAS. Because, as Marshall put it, the SAS "is an 'Internet of Things' device – it talks to devices, not people." Google also developed a planning tool for the SAS that it used for the demonstration, the report said.
In his prepared remarks at ISART 2015, Larry Strickling, assistant secretary of Commerce, said the Center for Advanced Communications (CAC), a collaboration between the National Telecommunications and Information Administration (NTIA) and the National Institute of Standards and Technology (NIST), will be an important player with its focus on cutting-edge research and development, experimentation and testing.
The key mission of the CAC is to serve both other federal agencies and industry to solve some of the challenges of spectrum sharing through testing, measurement and modeling capabilities, he said. One of its initiatives includes a spectrum monitoring project to measure spectrum utilization. Spectrum monitoring is important since it can help identify frequency bands of most interest for potential future sharing and support the enforcement of rules to avoid interference once sharing is in place.
CAC is currently measuring occupancy and emission levels of incumbent Naval radar systems in the 3.5 GHz band that the FCC recently opened up to sharing. The effort could lay the groundwork for moving from exclusion zones to coordination zones, and potentially it could grow into a more dynamic spectrum coordination and enforcement activity, which would allow greater commercial access to that spectrum, Strickling said.
The project is already collecting data from sensors in Virginia Beach, Va., and will be deploying sensors in San Diego, San Francisco and the Florida Keys in the months ahead. "Eventually we want to get this up and running in six locations around the country," he said.
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