EDITOR'S NOTE: Jules McNeff answers additional questions on the subject of spectrum protection and sharing in a special “GNSS Forum” extension of this installment of the "Thought Leadership Series" in this issue of Inside GNSS.

As Mark Twain once famously told a petitioner for investment advice: “Buy land. They are not making it any more.”

So it is with radio frequency spectrum, a limited and finite resource.

The recent effort by LightSquared, Inc., to operate a potentially interfering wireless broadband service in frequencies adjacent to GPS L1 bands increased the GNSS community’s awareness of just how precious a resource spectrum is.

Given such pressures, a couple of concepts have emerged as ways to protect and “share” spectrum — specifically, the “harm claims threshold,” which would mandate that receivers be built to withstand a predetermined level of interference, and the “adjacent-band compatibility assessment,” which would give potential manufacturers of systems proposing to broadcast in neighboring frequencies clear limits so that they can test and plan accordingly.

To help sort out the technical and political issues surrounding this topic, we called on Jules McNeff. Now vice-president for strategy & programs at Overlook Systems Technologies, McNeff has a deep and lengthy background in GPS program operation and policy, including service in the Office of the Assistant Secretary of Defense with responsibility for the agency’s navigation systems policy and overall management and oversight of the GPS program.