All Transitions Involve Decisions and Consequences

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Radar, Broadband Telecommunications, what do they have in common? Why they both eat up spectrum of course! Currently Radar occupies the largest allocation of prime spectrum. The reasons are historical and military related, so I won't bore you with the details. But let us not forget the other occupier of prime spectrum, that of Broadcast Television and Radio, i.e. BBC 1 and Radio 4 to you and me.  I am sure that shall interest you.

On the 18th of June the pivotal inflection point for reallocation of spectrum  for sharing was reached. The transition has begun once again in earnest in the US.  Well it would, wouldn't it?

The US and Spectrum Sharing and Geo-location Technology:

The driving force behind these events is, of course, the NTIA. An elite organisation in the true sense of the word: meaning 'Simply the Best'.

What did the NTIA do this time?

They simply released a report, the dry technical abstract of which reads:
"This report describes the 3.5 GHz Study. It explains the assumptions, methods, analyses, and system characteristics used to generate the revised exclusion zones for small-cell commercial broadband systems to protect federal radar operations (ship and land based) from aggregate interference in the band 3550?3650 MHz. The 3.5 GHz Study's exclusion zones are compared with the exclusion zones that were generated in the Fast Track Report, which considered macro-cell operations? Indeed!

However, the NTIA Blog posting puts in everyday language the reports context and importance. I quote:
"Today, the National Telecommunications and Information Administration (NTIA)ÿreleased an important technical report developed by engineers in NTIA?s Office of Spectrum Management (OSM) and Institute for Telecommunication Sciences (ITS) that provides the technical analysis supporting spectrum sharing in the 3550-3650 MHz band.ÿ It serves as a concrete example of our efforts to make more spectrum available to meet the exploding demand for commercial wireless broadband while protecting mission-critical Federal systems? Military systems to you and me.

Step forward E. Drocella, J. Richards, R. Sole, F. Najmy, A. Lundy and P. McKenna and take a bow. 

Their report namely TR-15-517: 3.5GHz Exclusion Zone Analyses and Methodology, in my opinion should be obligatory reading for both Radar and Broadband systems engineers everywhere. For rarely do the twain meet.

The NTIA Blog goes on to state:
"The Federal Communications Commission (FCC) in April approved an innovative regulatory framework that would enable commercial access to 150 megahertz of spectrum in the 3.5 GHz band.ÿ This framework grew out of NTIA's 2010 Fast Track Report, which identified the 3.5 GHz band as a possible candidate for spectrum sharing to fulfill the President?s goal of identifying 500 megahertz of additional spectrum for commercial wireless broadband by 2020. Federal agencies are currently using this spectrum to operate military shipborne, ground-based, and airborne radar systems?

"The Fast Track Report had proposed allowing commercial wireless broadband providers to have access to this spectrum where such use would not interfere with these critical high-powered radar systems operated by the Department of Defense (DoD). However, NTIA recognized that if exclusion zones - the areas of the country where commercial use was prohibited ? were too large, it would significantly limit the viability of deploying new commercial broadband services in the band. "To address this, NTIA engineers spearheaded groundbreaking analysis and modeling techniques and collaborated closely with DoD and FCC staff to minimize the size of these exclusion zones to the greatest extent possible without impairing the incumbent radar systems. This team effort resulted in significantly reduced exclusion zones " a 77% reduction in coastal geographic areas from the previous proposal ? maximizing the commercial market potential for new broadband services.ÿ These results, along with the pioneering regulatory framework that relies on technical solutions to minimize the impact of these zones, are the foundation of the FCC's new rules? Quite!

These new rules are part and parcel of the FCC Open Internet and Net Neutrality overarching agenda.

The NTIA Blog finishes with the following statement: 
"NTIA has long recognized that the 3.5 GHz band holds significant potential for exploring the next- generation of spectrum sharing technologies and methodologies, and can be a real-world test bed for driving greater productivity and efficiency in spectrum use. The work documented in this report was essential to opening up this opportunity. It is now up to all stakeholders to collaborate and innovate in maximizing the use of this valuable piece of spectrum real estate? Long recognised!

This is no understatement. Is it just the Americans who shall take up this challenge?  Certainly at first the simple answer is yes.

Throughout this process it is always wise torememberthat fundamentally the NTIA are still applying the Complex Number System mathematical model of the Electromagnetic Spectrum attributed to Maxwell, who of course, applied a Quaternion model. The Vector Calculus came later but that is a separate story.