Issue Brief

New Approaches to Private Sector Sharing of Federal Government Spectrum

  • By Michael J. Marcus, Sc.D., F-IEEE
June 24, 2009 |

As the U.S. economy and society becomes more and more information-centric and mobile, wireless systems are becoming a major factor in the efficient functioning of our society. Radio spectrum is a key economic input into wireless systems that power our information society and economy and enhance public safety and national security. Since the earliest days of radio regulation in the United States; federal government use of spectrum has been handled independently of other users’ access to spectrum. Thus, the FCC controls spectrum use by private parties and states and local governments while the Department of Commerce’s National Telecommunications and Information Administration (NTIA) controls federal government spectrum use.

Until recently all spectrum was distributed to possible users by administrative means. Spectrum access has generally been seen as a “zero sum game” in which spectrum was available either to one party or another mutually exclusive party. However, “green field” spectrum is now almost nonexistent in the populated areas of the United States, meaning growth in wireless technology use must come from more efficient use of spectrum resources. This efficiency could come from traditional efficiency improvements like modulation and coding advances and more intensive spatial reuse of spectrum (as in cellular communications). Although there have been significant advances in these areas in the past two decades, for many types of systems large (order of magnitude) increases in efficiency through these techniques are no longer achievable. Therefore, we must look to new means to more efficiently utilize spectrum. Advances in new types of spectrum sharing that allows underutilized spectrum to be used by more than one user, subject to interference and availability constraints that preserve access for the first user, offer the most promising means to maximize efficient use of spectrum resources.

In the following discussion, I will review the special case of federal government spectrum in the United States and possible new sharing mechanisms that would spur access for other users to this valuable spectrum. The current federal spectrum management system provides little incentive to allow sharing of existing federal spectrum and thus limits any such sharing to extremely conservative criteria to protect systems that were designed with no consideration of sharing. The focus here is not on sharing with existing federal systems, but rather how the next generation of federal systems could be designed with the goal of simultaneously implementing advanced federal agency wireless use, while also facilitating, interference free private sector sharing.

To read the full paper, dowload the PDF below.  

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There are real limitations to first and second genera-tion spectrum sharing with respect to how much spec-trum can be shared with a negligible risk of interfer-ence to critical federal government systems. However, if future federal systems are designed to enable and actively facili-tate spectrum sharing, then more efficient sharing is possible.

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