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pierredv : examples   42

Radio Interference from LED Lighting Systems | National Public Safety Telecommunications Council
"NPSTC has been following the issue of interference caused from some LED and fluorescent light system ballasts, which have disrupted both public safety communications and cellular wireless systems. We have also been informed that some USB3 powered computer hubs will cause interference to public safety portable radios operating in the 700 MHz band. NPSTC will publish a formal survey on this topic in early November."
RF  interference  RF  Examples  LED  USB3  NPSTC  fluorescents 
january 2015 by pierredv
'Space bubbles' may have led to deadly battle in Afghanistan - AAAS Science Mag Oct 2014
"The jagged peaks of Afghanistan have caused plenty of communications difficulties for U.S. forces, but researchers suspect that the doomed rescue mission may have fallen victim to a less visible source of interference: plasma bubbles. Their research, published online this month in Space Weather, suggests that turbulent pockets of ionized gas may have deflected the military satellite radio signals enough to cause temporary communications blackouts in the region." "The Takur Ghar battle occurred during Afghanistan’s “bubble season.” It was a reasonable hypothesis, but proving it might’ve been impossible if it weren’t for a lucky coincidence. At just about the time when things were becoming completely FUBAR atop Takur Ghar, NASA’s Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite had just completed a pass over the area. By using data from TIMED’s Global Ultraviolet Imager, scientists were able to confirm the presence of a plasma bubble between the battlefiel"
spectrum  interference  RF  Examples 
october 2014 by pierredv
LA building's lights interfere with cellular network, FCC says | PCWorld
"Fluorescent lights at Ernst & Young Plaza, a 41-story tower near the heart of downtown, emit frequencies that interfere with the Verizon Wireless 700MHz network, the agency said in a citation issued on Friday against building owner Brookfield Office Properties." Citation at http://www.fcc.gov/document/brookfield-office-properties
noise  interference  RF  Examples  cellular  Verizon  fluorescents  General  Electric 
march 2014 by pierredv
IEEE SA - 1900.2-2008 - IEEE Recommended Practice for the Analysis of In-Band and Adjacent Band Interference and Coexistence Between Radio Systems
Description: Technical guidelines are provided in this recommended practice for analyzing the coexistence or, alternatively, the interference between radio systems, operating in the same spectrum assignment or between different spectrum assignments.
ieee  standards  interference  RF  Examples 
october 2011 by pierredv
FAA Estimates $70+ Billion in Costs, Nearly 800 Deaths, Due to LightSquared Interference to GPS | Inside GNSS
"A Federal Aviation Administration (FAA) “conservative” assessment of changes in civil aviation that would result from the effect of LightSquared’s wireless broadband transmissions on GPS would exceed $70 billion dollars, largely because of delays and changes in the planned rollout of the Next Generation (NextGen) air traffic control (ATC) system."
insidegnss  LightSquared  GPS  interference  cost  trade-offs  RF  Examples 
september 2011 by pierredv
LightSquared and GPS - reference information from PNT.gov
This page provides information about potential interference to GPS receivers from the LightSquared communications network.
LightSquared  GPS  interference  reference  RF  Examples 
september 2011 by pierredv
LightSquared says GPS makers ignored filtering rules - Computerworld Aug 2011
IDG News Service - "GPS vendors have not complied with a 2008 Department of Defense recommendation that called for much better filtering of signals from adjacent spectrum bands, mobile startup LightSquared told the U.S. Federal Communications Commission on Thursday."
LightSquared  GPS  wireless  interference  x:computerworld  RF  Examples 
august 2011 by pierredv
Primer on Frequency Coordination
"This paper provides a general introduction to the radio frequency coordination procedures used by common carrier microwave system operators and by operators of satellite earth stations which use the so-called common carrier frequency bands. The procedures are based on FCC coordination and licensing requirements, as well as related industry practices that have evolved over the years. The same procedures are used by operators in several other radio services which use the same frequency bands as common carrier microwave systems."
usa  wireless  spectrum  frequency-coordination  interference  *  history  fcc  RF  Examples 
august 2011 by pierredv
Receiving weather satellite images
"For best results, you need to use a receiver developed specifically for the reception of weather satellites, which has the correct IF bandwidth. I use an R2FX APT receiver. Unfortunately this receiver, designed and made in Germany where the problem of close-by pager signals does not exist, suffers from desensitization and cross-modulation when the pager transmitters operate. This results in received images that are scarred with ugly interference bands. Receivers made in the UK by companies like Timestep and Dartcom are reputedly better, but unfortunately they are a lot more expensive."
satellite  radio  receiver  weather  interference  RF  Examples 
july 2011 by pierredv
47 CFR § 27.1133 - protection of BAS by AWS operations
47 CFR § 27.1133 that contains the requirement that “AWS operators must protect previously licensed Broadcast Auxiliary Service (BAS) or Cable Television Radio Service (CARS) operations in the adjacent 2025-2110 MHz band,”
fcc  regulation  interference  x:hallikainen  BAS  AWS  RF  Examples 
june 2011 by pierredv
47 CFR § 2.102 (f) on preventing harmful interference
47 CFR § 2.102 (f) provides a blanket requirement that licensees shall “use frequencies so separated from the limits of a band allocated to that service as not to cause harmful interference to allocated services in immediately adjoining frequency bands”
fcc  regulation  x:hallikainen  interference  RF  Examples 
june 2011 by pierredv
GPS jamming: No jam tomorrow | The Economist
"Navigation: As the uses of satellite-positioning technology continue to grow, what can be done to stop deliberate and dangerous jamming of the signals?"
navigation  GPS  jamming  interference  TheEconomist  RF  Examples 
march 2011 by pierredv
GPS chaos: How a $30 box can jam your life - tech - 06 March 2011 - New Scientist
"Signals from GPS satellites now help you to call your mother, power your home, and even land your plane – but a cheap plastic box can jam it all"
Interference case studies: San Diego Jan 2007 ex Navy jamming test; THV Galatea; 2006 GPS outage due to sunspot led to false billing by power companies
People cited: David Last, Donald Jewell, Todd Humphreys
Uses of GPS: airport landing systems, train routing, cellphone base stations, financial transaction timestamps, sync between power plants
GPS  eLORAN  satellite  hacking  jamming  interference  **  RF  Examples 
march 2011 by pierredv
NTIA Report 01-384: Measurements to Determine Potential Interference to GPS Receivers from Ultrawideband Transmission Systems
"This report describes laboratory measurements of Global Positioning System (GPS) receiver vulnerability to ultrawideband (UWB) interference. The laboratory measurements were performed by inserting increased levels of UWB interference until an operating GPS receiver lost lock. At each interference level leading up to loss of lock, reacquisition time, fundamental GPS measurements (e.g., pseudorange and carrier phase), status flags (e.g., potential cycle slips), and position data were sampled. A variety of UWB signals were tested, including aggregates of as many as six UWB sources. Two GPS receivers with different receiver architectures were tested."
UWB  GPS  interference  x:NTIA  RF  Examples 
february 2011 by pierredv
Northpoint Will Interfere With DBS Reception, DirecTv, Echostar Find | Communications Today | July 2000
"Testing shows that a controversial proposal by Northpoint Communications to use spectrum in the DBS band would unquestionably cause interference, Charlie Ergen, chairman and CEO of Echostar Communications [DISH], told attendees at the SBCS convention last week."
interference  wireless  northpoint  dbs  fcc  RF  Examples 
february 2011 by pierredv
SBE: FCC must protect ENG receive only users from AWS interference
SBE "objected to provisions of a Notice of Proposed Rulemaking mandating that AWS base stations suppress their out of band emissions (OOBE) by only 43dB. According to the filing, the suppression requirement for such OOBE should be increased to 67dB"
BAS  interference  aws  RF  Examples 
august 2010 by pierredv
IEEE letter (PDF) to FCC and NTIA on developing a more transparent framework for making “harmful interference” determinations.
"The AWS-3 deadlock may be replicated many times in the follow-on to a spectrum inventory, unless both the FCC and NTIA improve their approaches to making harmful interference findings."
"We believe that FCC and NTIA should make a general policy concerning the use of probabilistic models in harmful interference determinations"
fcc  ieee  interference  ***  filetype:pdf  media:document  RF  Examples 
may 2010 by pierredv
FCC PN requesting comments on draft rule for WCS/SDARS interference mitigation
April 16, 2010
"For example, the draft rules would create a guard band of 2.5 megahertz on each side of the SDARS spectrum in which mobile operations would not be permitted, resulting in a buffer between the two services. WCS out-of-band emissions would be reduced in steps to a level less than that of nearly any other mobile devices. The draft rules also place caps on the peak-to-average power ratio (PAPR) and duty cycle of the WCS transmitters. Furthermore, the draft rules also provide that, irrespective of compliance with the technical standards, if WCS operations cause harmful interference to the SDARS, WCS licensees have an obligation to correct such harmful interference."
"The draft rules would codify technical and licensing provisions for SDARS terrestrial repeaters. The draft rules also address concerns raised by the National Association of Broadcasters (NAB) about the use of terrestrial repeaters to originate local programming ..."
FCC  rules  regulation  WCS  SDARS  interference  filetype:doc  media:document  RF  Examples 
april 2010 by pierredv
Unprotected Six? : CommLawBlog
"National Public Radio (NPR) has asked the Commission to dump the Channel 6 protection obligations (set out in Section 73.525) which have been imposed on noncommercial FM stations for the last quarter century. While the proposal no doubt appeals strongly to NPR’s NCE-FM constituency, the television side of the universe – and particularly current Channel 6 licensees and viewers – can’t be happy..." "The protection requirements were imposed in the first place because the portion of the FM band reserved for NCE operations butts up against Channel 6, spectrum-wise." via Dale Hatfield
wireless  rf  interference  CommLawBlog  Examples 
january 2010 by pierredv
Eurostrategies LS telcom 2007 (PDF) = Study on radio interference regulatory models in the European Community
"This is the final report for the above study carried out for the Information Society and
Media Directorate-General of the European Commission under contract INFSO-B-
2006/45682 (SMART n°2006/0011) signed on 29 December 2006. The study was
carried out between January and November 2007 by Eurostrategies sprl of Brussels
and LS telcom AG of Lichtenau, Germany.
This final report was submitted to the European Commission on 26 October 2007 and
finalised on 29 November 2007."
via Scott Marcus
wireless  interference  EU  ***  filetype:pdf  media:document  RF  Examples 
december 2009 by pierredv
Military signals may jam garage-door openers
"Coming soon to dozens of military bases around the United States: radio signals strong enough to jam nearby garage-door openers. Between now and 2008, the military is supplying a new radio system to roughly 125 bases that uses the same frequency as the one relied upon by more than 90 percent of the remotely operated openers, Pentagon and industry officials say. "
garage-door-openers  interference  wireless  us  RF  Examples 
november 2009 by pierredv
Study of high performance filtering options forbase-stations and radar receiver application (Isotek for Ofcom)
"published an independent report from a study assessing the design of high performance radio frequency filters to improve the compatibility between adjacent radio services. The filters are designed for use in mobile network base stations operating in the 790-862 MHz and 917-921 MHz bands and in radar receivers operating in the 2.7-3.1 GHz band"
ofcom  interference  filetype:pdf  media:document  RF  Examples 
october 2009 by pierredv
RA EMC Awareness - Radio Susceptibility interference examples
Examples:
=TETRA basestations and Fylingdales lock drivers out of their cars
=GPS navigation vulnerable to TV antenna boosters
=HMS Sheffield disaster
=Problems with the U.S. radio system puts police officers at risk
rf  radio  interference  Examples 
october 2009 by pierredv
Consultation on the way forward for the future use of the band 872 - 876 MHz paired with 917 - 921 MHz | Ofcom
standard trade-off between in-band transmit power and adjacent receive channel filtering – and who would pay for the filtering.
ofcom  interference  rf  wireless  cellular  uk  Examples 
august 2009 by pierredv
Automatic Monitoring System – Phase II: Business Case & Trials | Ofcom
2007 work
"Phase I of the AMS project (http://www.ofcom.org.uk/research/technology/research/state_use/ams/) has resulted in three prototypes and a high level business model. The concept of an AMS network is that spectrum can be monitored in real-time across the UK so that (i) unlawful spectrum use can be policed; and (ii) spectrum can be re-allocated where it is not being sufficiently used – either through an auctioning or a trading regime."
"Unfortunately, the cost of rolling out a network of AMS stations is high... This Phase II study is intended properly to investigate commercial deployment issues, answer key questions on market demand for the service and establish potential users’ willingness to pay."
ofcom  spectrum  interference  measurement  rf  wireless  Examples 
june 2009 by pierredv
FCC Should Be Fair To WCS
By Randall Schwartz, WirelessWeek - April 01, 2002
critique of SDARS position
wireless  regulation  opinion  interference  WCS  SDARS  RF  Examples 
may 2009 by pierredv
The Wimax canary - Taiwan News Online
"Reports of critical interference with TV broadcasts by broadband wireless systems in the satellite C-band frequency are on the rise.
The most recent example, in Bahrain in the Middle East, tells a tale of hundreds of consumers - largely expatriates "
interference  wireless  RF  Examples 
september 2008 by pierredv
Channels "blocked"
"BAHRAIN'S Indian community is up-in-arms over satellite channels from home allegedly being blocked by Internet signals, broadcast on the same frequency"
Seems like an adjacent channel WiMAX/Satellite interference issue
interference  wireless  RF  Examples 
september 2008 by pierredv

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