NAB, Consultant Against Terrain Models for TV White Spaces
NAB and Red Technologies opposed terrain-based models, such as the Longley-Rice irregular terrain model, to determine available TV channels for white space devices. Comments were due Friday in FCC docket 20-36 on an October Further NPRM (see 2010290051). “Such a…
Sign up for a free preview to unlock the rest of this article
Export Compliance Daily combines U.S. export control news, foreign border import regulation and policy developments into a single daily information service that reliably informs its trade professional readers about important current issues affecting their operations.
model would lead to harmful interference to television service in pursuit of marginal, and likely illusory gains in spectrum efficiency,” NAB said. “Based on our experience implementing terrain-based propagation models onto commercial-grade spectrum access system,” it “requires significantly more processing power” than the current database, plus “higher end infrastructure,” said engineering consultant Red. The Wireless ISP Association, which had sought the change, disagreed with broadcasters. “Incumbent protection of TV stations is presently based on simplistic models that take into account only distance to a contour, ignoring terrain as a factor, and using only a single height above average terrain value computed on the basis of points 3 to 16 km from the transmitter,” WISPA said: “The Longley-Rice model is a widely accepted and understood method of estimating path loss on VHF through microwave frequencies that takes terrain into account while calculating several modes of propagation.”