In 2010, the President of the United States directed that 500 MHz of federal and non-federal electromagnetic spectrum be made available for new wireless broadband services by the year 2020. As a result, the Federal Communications Commission has been conducting auctions of licenses for spectrum use, including frequencies used by Department of Defense (DoD) systems.
One of many ongoing post-auction projects is an effort to determine if certain United States Marine Corps systems can move to and share the 2025-2110 MHz frequency band with commercial broadcasters. Electronic news-gathering (ENG) equipment is used to obtain nearly all news shown on television and streamed via the internet, and those systems operate primarily within the 2025-2110 MHz frequency band.
Live testing was recently conducted March 26 through March 30, 2018, at Marine Corps Air Station (MCAS) Miramar. This was a concerted effort between the KUSI San Diego television station and the Marine Corps, with representatives observing from the National Association of Broadcasters (NAB), the Defense Spectrum Organization (DSO), the Navy-Marine Corps Spectrum Center (NMSC), and the Office of the DON Chief Information Officer (CIO). The testing involved Marines from the First Marine Expeditionary Force (I MEF) and the Third Marine Aircraft Wing (3rd MAW) operating the Corps’ MRC-142 radio at various locations near MCAS Miramar.
The MRC-142 is a vehicle-mounted line-of-sight radio system and the backbone of the Marine Corps tactical radio relay network. An independent testing team from the Aerospace Corporation utilized a test equipment configuration consisting of multiple feed horns capable of capturing signals from both the TRR and ENG systems. As part of this configuration, spectrum analyzers were situated at numerous locations to detect and record any instances of interference between the KUSI San Diego electronic news-gathering equipment and Marine Corps MRC-142 radios.
Information collected expands upon data sets previously ascertained from U.S. Army and U.S. Navy testing. This will inform the analysis that will ultimately determine if it is possible for these critical Marine Corps systems to share this portion of the electromagnetic spectrum with the broadcasting community.
The DoD is challenged with balancing its ever-increasing spectrum needs against decreasing spectrum in which to operate. Working with industry in test situations like this is one avenue being pursued to maintain viable spectrum access and ensure sustained defense system capabilities.
Guenever Aldrich is a Professional Engineer (PE) and the DON Spectrum Relocation Lead for the Office of the DON CIO. Amy Schmidt is a Certified Cost Estimator/Analyst (CCEA) and provides contractor support as the senior spectrum analyst for DON spectrum relocation.