Enforcement and Spectrum Sharing: Case Studies of Federal-Commercial Sharing

Spectrum sharing has moved from being a radical notion to a principal policy focus in the past decade. This becomes evident as one compares the FCC’s Spectrum Policy Task Force (SPTF) report from 2002 [1] with the President’s Council of Advisors on Science and Technology (PCAST) Spectrum report [2]. The former report considers spectrum sharing as a possible option while the latter makes spectrum sharing a key strategy for spectrum access.With the significant exception of license-free wireless systems, commercial wireless services are based on exclusive use. With the policy change facilitating spectrum sharing, it becomes necessary to consider how sharing might take place in practice. Beyond the technical aspects of sharing that must be resolved lie questions about how usage rights are appropriately determined and enforced. Weiss et.al. [3] developed a law-and-economics based framework for enforcement as it could be applied to dynamic access networks. While useful, this high-level discussion does little to assist policymakers on specific problems.To address this gap, this paper examines particular cases in spectrum sharing and studies how the enforcement principles might be applied. The bands are some of those being considered by the NTIA for Federal-commercial sharing and have been discussed by NTIA’s “Commerce Spectrum Management Advisory Committee (CSMAC)” (http://www.ntia.doc.gov/category/csmac). The first case examines the 1695-1710 MHz band, which is currently being used by the National Oceanic and Atmospheric Administration (NOAA) as primary user providing the weather satellite services (MetSat) downlinks (space –to-earth). Since earth stations are stationary, it provides a good starting point for working out sharing, especially from an enforcement perspective. The second case focusses on the 1755-1850 MHz band, where the primary user is mobile and the identity and characteristics of the secondary user are known (commercial LTE). Finally, we study the 3550-3650 MHz band, where the primary user is high power shipborne radars and the expected secondary use is varied and includes unlicensed services.From the PCAST report, it is clear that trust and accountability are primary barriers to spectrum sharing. Overcoming these barriers will require a clear approach to enforcement. As outlined in [3], various approaches to enforcement exist, each of which have opportunity costs as well as real costs. We explore the enforcement requirements of the various usage scenarios in the bands outlined above. For each of these, we explore the approaches to enforcement that may be taken and, to the extent possible, quantify the implications of each approach. We use these cases to sharpen the analysis begun in [3] and to provide specific guidance to policymakers.Bibliography[1] FCC, "Spectrum Policy Task Force Report," ET Docket No. 02- 135, Washington DC, 2002.[2] PCAST, "Realizing The Full Potential Of Government-Held Spectrum To Spur Economic Growth," Washington DC, July 2012.[3] M. Weiss, W. Lehr, L. Cui and M. Altamimi, "Enforcement in Dynamic Spectrum Access Systems," in TPRC , 2012.