Pentagon launches next phase of spectrum-sharing program

The electromagnetic spectrum is an increasingly contested domain, particularly in the frequencies the military most wants to use, so researchers are looking for new, efficient ways to share the spectrum. 

In lieu of work conducted in Phase 1 of the Defense Advanced Research Projects Agency’s Shared Spectrum Access for Radar and Communications program, DARPA is now asking for proposals regarding Phase 2.

The SSPARC program – which at its initial inception, in concert with the Advanced RF Mapping program, sought to “fine-tune spectrum use and develop ways of sharing bandwidth” under the Defense Department’s Electromagnetic Spectrum Strategy – is aimed at improving spectrum sharing capabilities among military radars and military communications systems and military radars and commercial communications systems.

According to DARPA’s broad agency announcement for Phase 2 proposals, “Proposed research should investigate innovative approaches that enable revolutionary advances in science, devices, or systems.  Specifically excluded is research that primarily results in evolutionary improvements to the existing state of practice.”

DARPA wants to ameliorate spectrum congestion as it “limits operational capabilities due to the increasing deployment and bandwidth of wireless communications, the use of net-centric and unmanned systems, and the need for increased flexibility in radar and communications spectrum to improve performance and to overcome sophisticated countermeasures.” Since radar and communications take up most of the spectrum below 6 GHz, the most highly desired portion, DARPA wants to develop technologies to better enable sharing across the spectrum. 

In Phase 1, the AN/SPY 1 radar, used in the Aegis Combat System, and the AN/TPS-80 radar were studied.  Phase 1 used simulation and analysis to demonstrate if spectrum sharing would be feasible while simultaneously preserving radar and communications performance. Four organizations performed work under Phase 1: Michigan Technological University, SAZE Technologies, Lockheed Martin Advanced Technology Laboratories and Science Applications International.

The spectrum-sharing challenge research proposals for Phase 2 should focus on the S-band, in the range of 2 GHz to 4 GHz. In terms of radar research, DARPA is interested in ground or naval-surface, electronically steered phased array and multifunction, which combines air surveillance, air tracking, non-cooperative target, identification, and optionally, weather monitoring. Communications system research should focus on ground or naval-surface, military Mobile Ad-hoc Network (MANET) and commercial small-cell broadband.

The technical approach and challenge has not changed from Phase 1 of the SSPARC program.

Interested parties looking to submit proposals for work on Phase 2 must be capable of performing research on sharing system design and separation mechanisms, analysis and simulation to assess feasibility and performance of the approach, implementation of a prototype test system, laboratory testing of the prototype system, preparation of a transition plan for the sharing system and produce a base effort final report, according to the BAA. Additionally, interested parties may also conduct field data collection and a limited-scale demonstration, and write an option effort final report, though these measures are optional.