CBRS:An Unproven Spectrum Sharing Framework

In 2012 the President’s Council of Advisors on Science and Technology (PCAST) was asked to write a report on how it envisioned the allocation of wireless spectrum in the future. Taking the position that clearing spectrum for unencumbered use was too difficult in some cases, the report called for sharing spectrum between incumbent federal, state and local users and commercial users. Licenses should be small, reused, and relicensed and would thereby increase the capacity by a factor of 1,000. The Federal Communications Commission formalized this approach with the creation of the Citizen’s Broadband Radio Service (CBRS) out of 150 megahertz (MHz) of spectrum in the 3.5 gigahertz (GHz) band. Today, a decade after this approach was proposed, a review of the current CBRS marketplace reveals a gap between the promise of this type of sharing and its reality. Key points include:

• Real-world studies indicate low utilization of CBRS spectrum, while there is no way to measure whether CBRS spectrum is being used at greater levels of efficiency
• The most prevalent use cases are traditional wireless deployments
• The supply of sharing services is declining, particularly those supplied by non-traditional providers, driven by low demand for these services

This situation can be explained by the following factors: Federal preemption of commercial spectrum rights are a barrier to applications that require guaranteed levels of service; Low power levels and small license sizes limit the ability to provide coverage and increase cost; This sharing has proven to be more complex than anticipated.