Interesting People mailing list archives
White Space update
From: David Farber <dave () farber net>
Date: Mon, 27 Oct 2008 19:49:45 -0400
Begin forwarded message: From: WWWhatsup <joly () punkcast com> Date: October 27, 2008 7:08:25 PM EDT To: Dave Farber <dave () farber net> Subject: White Space update As you may be familiar the NYC Council Tech Committee recently held a public hearing after the Broadway and TV industries lobbied for a resolution urging the FCC to withhold approval of White Space Devices (WSDs) for broadband access - the concern being that they would interfere with wireless microphones and DTV transmissions http://nycbroadband.blogspot.com/2008/09/white-spaces-hearing-webcast.htmlThe FCC's engineers, after conducting tests, released a report on Oct 16.
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-08-2243A3.pdf Reading the FCC engineer's report, it seems far from giving WSDs an entirely clean bill of heath. * Several tests were performed with DTV signals present in adjacent channels. These tests showed that in the presence of moderate-to-strong signals in a first adjacent channel, the detection threshold sensitivity of all of the devices was severely impacted. For some of the devices, the degradation in the detection sensitivity was as much as 60- 70 dB. In some cases, the degradation was such that the detection threshold could not be measured. This could impact significantly the ability of the devices to reliably detect TV signals within stations service areas. * The Microsoft, Philips and I2R devices were tested for their ability to sense for the presence of wireless microphones (both FM/analog and digital) operating within UHF TV channels. With no other signals present, the devices were able to detect wireless microphones at levels ranging from -103 dBm to -129 dBm depending on the type of microphone, and the device. In the presence of DTV signals in adjacent channels, the detection threshold was degraded such that it affected the ability of the devices to reliably detect the microphone signals. However, in summary, it concludes: These devices have been developed to demonstrate capabilities that might be used in unlicensed low power radio transmitting devices that would operate on frequencies in the broadcast television bands that are unused in each local area. At this juncture, we believe that the burden of proof of concept has been met. We are satisfied that spectrum sensing in combination with geo-location and database access techniques can be used to authorize equipment today under appropriate technical standards and that issues regarding future development and approval of any additional devices, including devices relying on sensing alone, can be addressed.On Oct 17 the TV interests filed an 'Emergency Request' asking that any vote be delayed
to allow for a 70 day response period to the report http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6520176037On Oct 20 Rural Broadband interests filed an 'ex parte' letter emphasizing that WSDs
should be 1) mobile, and 2) unlicensed. <http://main.nc.us/whitespaces/files/fcc-letter.html>http://main.nc.us/whitespaces/files/fcc-letter.html The FCC, as it now stands, will vote on Nov 4 http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-286069A1.pdfFreepress is strongly advocating the public to encourage the FCC to stick to its guns
and approve WSDs. https://secure.freepress.net/site/Advocacy?alertId=285&pg=makeACall Joly MacFie 212 608 1334 http://isoc-ny.org ------------------------------------------- Archives: https://www.listbox.com/member/archive/247/=now RSS Feed: https://www.listbox.com/member/archive/rss/247/ Powered by Listbox: http://www.listbox.com
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- White Space update David Farber (Oct 27)