An FCC official tells Congress that the commission is on
track to exceed its 300 MHz by 2015 goal for freeing up spectrum for mobile
wireless broadband and is looking hard at the issue of receiver performance in
light of that effort.
That is according to Ron Repasi, deputy chief of the Federal
Communications Commission's Office of Engineering and Technology, in prepared
testimony for a hearing Thursday on "The Role of Receivers in a
Spectrum-Scarce World."
Repasi also said the FCC was working on defining harmful
interference and how to protect existing services while allowing for adjacent
new services, an issue that is growing in importance as the FCC frees up more spectrum.
That includes through incentive spectrum auctions aiming to get up to 120 MHz
from broadcasters, though it is likely to be less than that.
The FCC's Technological Advisory Council (TAC) has been
looking at the role of receivers and Repasi says that one approach that has
been discussed is "based on developing interference protection limits that
would define what signal levels services would be expected to tolerate from
adjacent services. A licensee would need to demonstrate that it is experiencing
signal levels above the limit in order to make a claim of harmful
interference," he says. "The TAC is considering whether the
interference protection limits might be established through a multistakeholder
process and whether rules would be appropriate."
While Repasi points out that receiver performance has
generally been left to the marketplace, that is not always the case
"because receivers can sometimes pick up energy outside the spectrum
provided for the service in which they operate." That was the case for
LightSquared, which got a conditional waiver to use spectrum adjacent to GPS,
but had that waiver put on indefinite hold because GPS receivers were receiving
out-of-band transmissions.
"Receiver performance is becoming increasingly
important as a limiting factor as we move to repurpose spectrum and pack more
services closer together on the spectrum chart. The continuing challenge for
the commission will be to maximize the amount of usable spectrum for cost
effective deployment of new communication services while sufficiently
protecting incumbent receivers," he said.
That is the balancing test the FCC was apparently applying
when FCC chairman Julius Genachowski recently proposed putting limitations on
spectrum rights owned by Dish -- for a planned 4G wireless broadband service --
in spectrum adjacent to a block the FCC will be auctioning, also for wireless
broadband.
