DARPA issues collaborative spectrum sharing challenge

Static spectrum allocation is going to pass its use-by date soon, according to the Defense Advanced Research Projects Agency (DARPA), which has kicked off a US$2 million challenge to find co-operative ways to share radio frequencies.

DARPA's project page, here, describes its aim simply: it wants to replace static spectrum allocation by building machine learning into radio sets. Its Spectrum Collaboration Challenge (SC2) will give entrants three years – from 2017 to 2020 – to create systems for “on-the-fly sharing of spectrum at machine timescales”.

The project will be closely watched by the mobile telecoms industry, which is looking at competing proposals for spectrum sharing.

Just how to share spectrum – for example, in LTE or 5G systems that might overlap with Wi-Fi spectrum – is a debate that's set different interests at daggers drawn. The Wi-Fi corner, backed by cable broadband companies, is wary of efforts like LTE Unlicensed (LTE-U), demanding that any application designed to use unlicensed spectrum for cellphones follow a “listen before you talk” approach.

In other words, an LTE-U radio set would not start transmitting in bands like 5 GHz if there's an existing user.

At Mobile World Congress earlier this year, a group of vendors unveiled their attempt at brokering a spectrum peace, the MultiFire Alliance.

DARPA's competition goes beyond such discussions. As the agency's media release states the “Spectrum Collaboration Challenge (SC2) will reward teams for developing smart systems that collaboratively, rather than competitively, adapt in real time to today’s fast-changing, congested spectrum environment”.

William Chappell, director of DARPA's Microsystems Technology Office (MTO) says “The current practice of assigning fixed frequencies for various uses irrespective of actual, moment-to-moment demand is simply too inefficient to keep up with actual demand and threatens to undermine wireless reliability”.

The timetable of the challenge includes two preliminary contests, with the final in 2020.

DARPA says SC2 will be supported by the “largest-of-its-kind wireless testbed, which will serve during and after the SC2 as a national asset for evaluating spectrum-sharing strategies, tactics, and algorithms for next-generation radio systems”.

Researchers will be able to access the testbed, dubbed the “Colosseum”, to simulate large-scale experiments in “user-defined RF environments, such as the wireless conditions of a busy city neighbourhood or battle setting”.

DARPA says it will provide full details of SC2 in an upcoming broad agency announcement that will pop up on the FedBizOpps.gov site. ®