3.5 GHz Small Cell NPRM

About a year back, the FCC issued a notice of proposed rulemaking (NPRM) inviting comments on its plan of establishing what it calls "a new Citizens Broadband Service in the 3550-3650 MHz band". The 65-page detailed proposal can be accessed from this link, with some of the key points being:

• 100-150 MHz of contiguous spectrum being made available with small cells as a target application.
• A three-tiered shared access model managed by a spectrum access system (SAS). The FCC cites dynamic database as a starting point for SAS but is soliciting other interference mitigation ideas.
• The tiered shared access model is based on Qualcomm's Authorized Shared Access (ASA) and consists of the following three access tiers: 
• Incumbent Access: Only authorized federal and legacy 3.5 GHz Band users
• Priority Access: Critical, QoS dependent users at specific, targeted locations. One of the key aspect that FCC is seeking comments on is "who these eligible users should be" and they suggest it could include hospitals, utilities, state and local governments
• General Authorized Access: Wide range of residential, business, and others, including wireless telephone and Internet service providers
• Specific interference mitigation schemes, deployment strategies, and the design of the SAS database has not been specified, and are areas where the FCC is seeking comments. 

As expected, the NPRM has attracted a lot of attention from various businesses, industry groups, researchers, and individuals. Till date, more than 200 comments have been filed; a few interesting tidbits about the comments filed: 

• Google has submitted, by far, the most number of comment documents - 12 so far, totaling more than 120 pages!
• Most wireless service providers and their component suppliers are arguing for opening the Priority Access tier to wireless/mobile service providers. 
• Several comments, including those from Alcatel Lucent, WiMax Forum, and BLiNQ Networks have made the case for including small cell backhaul as a major use-case for the spectrum
• Notably, Microsoft has argued for ensuring that the Priority Access tier is limited to mission-critical users. It has requested the commission to make sure "that the licenses do not provide any single company or set of companies with excessive control over the spectrum."
• TV Broadcasters, including CBS, Fox, Time Warner, Viacom, and Disney have a problem with the FCC's plans. It says the new band "would be very problematic for incumbent C-Band (3700-4200 MHz) users, which generally includes the entire video distribution industry -- both broadcast and cable -- throughout the United States."

It seems like the FCC is quite active in trying to finalize its proposal for the 3.5 GHz band and is organizing, among other initiatives, a workshop to discuss the "Creation of a Spectrum Access System" on Jan. 14th, 2014. The key details that remain to be seen are which entities will be eligible for the Priority Access tier and what restrictions will be applied to the General Access users.