New Bandwidth at 3.5 GHz

The FCC has announced its intent to release some 150MHz of bandwidth at 3.5 GHz. They state:

The Federal Communications Commission today took steps to provide more spectrum for general consumer use, carrier-grade small cell deployments, fixed wireless broadband services, and other innovative uses, through the creation of a new Citizens Broadband Radio Service. The Commission  proposed rules for the Citizens Broadband Radio Service in a Further Notice of Proposed Rulemaking that advances the Commission’s efforts to meet the growing demand for spectrum by  proposing to make 150 megahertz available in the 3.5 GHz Band. The FNPRM proposes innovative spectrum sharing techniques to unlock the value of the spectrum between 3550 MHz and 3650 MHz, and seeks comment on extending the proposed service to 3700 MHz. Specifically, the FNPRM proposes a three-tiered access and sharing model comprised of federal and non-federal incumbents, priority access licensees, and general authorized access users. Together, the proposals seek to promote flexibility and innovation by leveraging advancements in technology to facilitate sharing between different users and uses, including incumbent government uses.

This may represent a significant opportunity for drastic expansions of broadband. Using MIMO and OFDM alone means well in excess of 1 Gbps capabilities. The only weakness is that propagation at 3.5GHz is line of sight.

This proposal is a result of a PCAST Report. The Report proposes (also see dailywireless piece on this):

Today’s spectrum users are in three categories: Federal users, licensed commercial users, and unlicensed commercial users. The proposed system will add three new categories. The first is Federal Primary Access, for legacy Federal users that share their spectrum on a first priority basis with other Federal users or commercial users. Conflict is managed by registering spectrum usage in a database. Secondary Access users are Federal or commercial users that have the next priority to shared Federal spectrum. Applications that require higher power and better quality of service than today’s unlicensed devices will benefit from this category, although a fee may be required to access this spectrum. The third category, General Authorized Access, has the lowest priority, and supports less critical low power applications such as meter reading or entertainment.

We have proposed a more robust real time approach almost a decade ago when examining Software Defined Radios and had held discussions with FCC members at the time.

In fact our proposal allowed for real time adaptive spectrum management in a real time bidding approach. The bidding approach also mimicked a Bitcoin payment system. It is good to see that some of these ideas have some legs, albeit very slowly. Then again it is the FCC after all.