03.27.2009 04:15 PM
Cable Lobby Warns of Interference from Unlicensed Devices
WASHINGTON: The main trade association representing cable TV operators has jumped into the white space fray. The National Cable and Telecommunications Association filed a petition for reconsideration of the FCC’s approval of deploying unlicensed devices in the unoccupied broadcast TV bandwidth that’s come to be referred to as “white space.”
“In adopting these rules, the Commission heavily weighted its decision on the side of promoting new wireless broadband services in the TV broadcast band and, while purporting to take into account any adverse effect on broadcasters, it gave little regard to the impact on existing and up and coming cable services,” the NCTA filing states. “Indeed, the Commission failed in several major respects to adopt precautions to protect cable consumers from proven harmful interference from white spaces devices.”
The NCTA said the 100 mW power level approved for unlicensed devices “will interfere with cable television viewing, especially in adjoining housing units, and could adversely impact cable modem Internet access and other cable services in the home.”
The filing said field studies conducted by Carl T. Jones Corp. showed that 100 mW unlicensed devices can interfere with cable TV reception at a distance of 80 feet--15 feet farther than the NCTA originally predicted.
“This means that cable services will suffer significantly--in the form of a noisier picture to the complete drop off of the picture in the case of digital signals--as a result of signal ingress from [unlicensed devices] operating as far as several rooms away,” the filing stated. “Customers also could experience interference to their cable modem and digital telephone service.”
The cable lobby said it wasn’t looking for absolute protection from interference, but rather a lowering of the allowable power level of unlicensed devices. The FCC approved the deployment of both mobile and fixed unlicensed devices in TV channels traditionally left open to prevent co-channel interference. The bandwidth is not entirely unused, but often populated with wireless mics, for example. The use of wireless mics is typically coordinated with local broadcast TV stations, whereas unlicensed devices would be difficult if not impossible to track should they cause interference to broadcast or cable TV reception.
The NCTA asked the commission to consider changes to its rules governing unlicensed devices that would offer greater protections to both cable head-ends and subscribers. -- Deborah D. McAdams