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Receiver standards

GAO Receiver Report

This week GAO released a report entitled “SPECTRUM MANAGEMENT: Further Consideration of Options to Improve Receiver Performance Needed”, shown at left. Your blogger has in the past been impressed with GAO reports on spectrum issues as giving a “breath of fresh air”, this one just covers ground that has been tread on many times.

The report repeats that FCC in general lacks authority to regulate receivers and that NTIA has such authority with respect to federal users. Buried in page 20 of the report is the fact that FCC was able to creatively use its limited power to create a de facto receiver immunity standards in the 800 MHz band to help solve the Nextel/Public Safety problem:

For example, FCC defined the minimum levels of performance that a receiver must meet to make a claim of harmful interference in the 800 MHz band.

Thus FCC could take similar additional steps in other bands without new legislation.

The report accepts without questioning NTIA’s claimed efficiency at setting receiver standards, but doesn’t ask the question how certain NTIA is about whether federal systems actually meet those standards. Since NTIA does not have an equipment authorization systems, how is compliance verified?

Finally, it gives not mention at all the long standing FCC/NTIA/FAA dispute over receiver immunity standards for Instrument Landing System receivers. While receiver standards are difficult to develop, in the ILS case there is an ICAO Convention standard that FAA will not required for all aircraft in the US because of would offend AOPA, the NRA-equivalent for general aviation. (Here is my fact sheet on this issue.)

The basic reason for this type of problem is that receiver standards are often an economic externality in which the party purchasing the improved receiver gets no tangible benefit. The GAO report does not delve into this issue at all!

FCC Workshop on Spectrum Efficiency and Receivers

As the announcement at the left shows, the FCC website is announcing a 2 day workshop on “Spectrum Efficiency and Receivers”. The workshop was originally announced on February 24, 2012. The home page announcement has a link for each day, but they go to pages with the exact same content:

As part of the Commission’s efforts to enhance the use of spectrum for mobile broadband, the FCC Office of Engineering and Technology, in conjunction with the Wireless Telecommunications Bureau and the Office of Strategic Planning will host a workshop on "Spectrum Efficiency and Receiver Performance." The workshop will be held on Monday, March 12, 2012 and Tuesday, March 13, 2012, in the Commission Meeting Room at FCC Headquarters in Washington, DC.

The role of receivers in enabling access to spectrum for new services implicates federal stakeholders, as well as the private sector. Receiver performance issues have often arisen as a conflict between legacy stakeholders and new entrants where deployment of new technologies and services threatens to adversely impact an incumbent or place restrictions on the new entrant. Past examples include interference issues between new cellular radio systems and public safety radio systems, satellite digital radio systems and proposed terrestrial data services, unlicensed WiFi systems and FAA weather radar systems, and ancillary terrestrial service on mobile satellite spectrum and GPS. The resolution of such matters has historically required a public process involving regulators, stakeholders and other parties. Because such discussions sometime begin upon the introduction of a new service or technology, full deployment of such new services could be hindered. New approaches to spectrum management focusing on spectrum efficiency and receiver performance may enable more assured deployment of new services and reduce the necessity for the involvement of regulators.

This two-day workshop will discuss the characteristics of receivers and how their performance can affect the efficient use of spectrum and opportunities for the creation of new services. Key topics will include current practices for receiver design, case studies involving interference due to receiver characteristics, and approaches for promoting interference avoidance and efficient use of spectrum, given the current receiver base and potential future deployments. The workshop will include perspectives from licensees, equipment manufacturers, component providers, and other interested parties.

Apparently there will be panels of speakers, but they have not been announced. Nor has any sort of agenda beyond the above been announced.

(I was surprised by the mention of “unlicensed WiFi systems and FAA weather radar systems” as I have previously written this appears NOT to be a receiver problem, but rather an SDR security issue for the unlicensed cognitive radio systems. Oddly, my September 2011 appeal of an initial redaction of a FOIA request has never been acted on by FCC/OGC. I believe the requested document with fewer redactions would confirm the real nature of the TDWR problem. Motorola is fighting the release of the document with fewer redactions in a “reverse FOIA” action.)

My suspicion is that there is a major coordination problem among the various power that be within FCC on both the agenda and the speakers, probably in their attempt to pacify various industry sectors who have their own view of the issue. Perhaps there is an NTIA problem also.

NTIA has classically been in favor of receiver standards, claiming they have them for federal systems. (Mostly true.) However, NTIA has been unwilling to pressure FAA into adopting 20 year old ICAO Instrument Landing System receiver immunity standards that are used around the world and has been strangely silent on the issue of GPS receiver standards.

In any case, it seems rather strange to have a 2 day workshop with no published agenda 3 working days before it starts.


The afternoon of March 9, the agenda was released.


The Powerpoint presentations used are available now on the (ever chaotic) FCC website.

Here are the videos of the 2 days: