DoD Implicitly Requiring Policy-Based DSA on SDRs?

Posted in Uncategorized at 11:26 pm by JamesNeel

I attended a talk by Jeff Boksiner at the IDGA SDR conference where he spoke on DOD Instruction 4650.01 issued on Jan 09, 2009 (pdf), which requires new devices to have a Spectrum Supportability Risk Assessment (SSRA) performed at each acquisition milestone (conceptual, experimental, developmental, operational) to determine the impact on all known “spectrum dependent systems” (SDS) where the devices will be deployed.

Officially, it’s not used for a go/no-go decision on the purchase / acquisition, but if it degrades performance too much (either of their own or another system, including systems of other friendly nations), you know it will. In theory, vendors will adjust their designs (e.g., bandwidths and operational channels) when performance is too degraded.

In my interpretation, this regulation is implicitly mandating the use of DSA-based policy-enabled software defined radios because of the costs of potential redesigns and the inherent advantages of SDR and policy-based cognitive radios.

The following are a few excerpts from the instruction.

Related to apparent preference to DSA / CR / SDR systems


b. Spectrum policy and spectrum management functions shall be guided by the following core principles:

Pursue spectrum-efficient technologies to support the increasing warfighter demand for spectrum access and encourage development of S-D systems that can operate in diverse electromagnetic environments (EMEs).




g. In accordance with Reference (f), DoD Components shall consider sharing the spectrum with other Federal agencies and with commercial spectrum users. Sharing of spectrum shall be accomplished:

(1) Without degradation to the DoD mission.

(2) In a manner that provides current and future DoD users with sufficient regulatory protection.[emphasis mine]

(3) With minimal risk that such sharing will result in loss of access to the spectrum necessary to perform the DoD mission.

And why I think it’s mandatory:

d. DoD Components shall obtain U.S. Government (USG) certification of spectrum support, as required by Reference (f), prior to authorization to operate for experimental testing, developmental testing, or operations of S-D systems in the United States and its possessions (US&P). As required by Reference (e), USG certification of spectrum support shall be obtained prior to submission of cost estimates (i.e., prior to Defense Acquisition System Milestone B (Reference (i)) for development or procurement of major S-D systems and for all space and satellite systems. In addition, some HNs require their own certification before providing authorization to operate.

From Enclosure 3

(1) Certification of spectrum support shall be obtained as required (Reference f) prior to authorization to operate for experimental testing (Stage 2), developmental testing (Stage 3), or operations (Stage 4) of S-D systems. (See Chapter 10 of Reference (f) for descriptions of the Stages of Certification.)

Since this requirement is by operation , potentially doing a redesign for each deployment will be insanely costly. Assuming the set of SDSs grows over time (as more and more radios are deployed), then even deploying into the same region will be a moving target.

However, according to Jeff’s presentation, there is an interest in translating these tests and requirements into policies expressed in software that a policy-defined radio could interepret. Then if a radio can be shown to support all dynamically defined policies, then the same design can be fielded in each scenario and be guaranteed to conform to these changing spectrum support requirements.

In other words, DoD radio designers are now faced with the following two choices:

  1. Non-recurring engineering costs become recurring engineering costs as radios are potentially redesigned for every purchase.
  2. Incur larger front-end engineering cost to design a radio that implements policy constrained DSA on an SDR and then allow these changes to be reflected in the policy control.

Add in the additional time-delays that the multistage SSRA process will add to the development of non-DSA polikcy constrained radios, and I think it’s a no-brainer.

So I’m marking January 9th 2009 as the day that the DoD mandated policy-defined, DSA-enabled SDRs for all future purchases. [Edited 3/4/9 to clean up formatting]

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