Could Ultrawideband Fuzz Cable Images?

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Washington— A wireless-broadband technology that operates at low power levels has the potential to disrupt satellite feeds between cable networks and thousands of headends, according to the National Cable & Telecommunications Association.

A coalition of numerous cable programmers — including C-SPAN, A&E Network, Home Box Office and Showtime Networks Inc. — wants the Federal Communications Commission to modify rules adopted in 2002 to eliminate potentially crippling interference from ultrawideband (UWB) providers.

The FCC has added an item on the matter to its Dec. 15 public-meeting agenda.


In a Dec. 3 letter, the NCTA voiced support for the coalition and told the FCC that UWB posed a significant risk to the quality of signals viewed in millions of cable-TV homes.

“Even a slightly degraded signal due to increased noise will reduce satellite-link margins and system availability and ultimately can lower the quality of services that are provided to consumers,” wrote NCTA senior vice president of science and technology William Check.

The vast majority of national cable networks use so-called C-band spectrum (3.7 Gigahertz-4.2 GHz) to beam their services, via satellite, to 9,000 cable headends around the country.

UWB providers have been allocated 7.5 GHz of spectrum that overlaps with the C-band, but UWB’s low power requirements were not expected to raise interference issues.

However, Check said that because the FCC imposed no limitation on the deployment of UWB emitters, the combined “noise floor” created by a surfeit of UWB emitters could cause harmful interference with cable-network downlinks.

“Under the current rules, cable operators and cable programmers have no guarantee that satellite-distribution systems will remain free from interference,” he added.

A nascent technology, UWB offers a data rate that could reach as high as 1,000 Megahertz per second, perhaps making the service a potential rival to cable, broadcasting and wireless providers. UWB is so fast that it can download a Hollywood movie in just a few seconds.

Some see UWB’s strength mostly in routing data around homes and offices at lightning speed.

The cable-dominated coalition also includes broadcasters CBS and Fox, because their network programming is delivered to affiliates using C-band spectrum, a cable attorney said.


The group hired Alion Science and Technology to test potential UWB interference. After Alion identified UWB harm to C-band transmissions, the group called on the FCC to require UWB to operate in the C-band at reduced power levels, or to restrict full-power UWB to C-band uplink frequencies.