Slashdot Mirror
Boston TV Signals Disrupting Police Radio in NJ
jeffy124 writes "WCVB, a digital TV station in Boston, is disrupting police radio communications in South Jersey. It seems that under certain weather conditions, the signal reaches here travels 270 miles (it's normally 50) and blacks out the police frequencies, making communication between officers and from 911 call centers impossible. The article seems to suggest that as more TV stations go digital, more small-town police radio will be affected, as the digital signal is significantly stronger than analog. Insert Joisey-joke here."
I think it's a safe bet that we'll see more donut commercials on digital television broadcasts- it ensures that it reaches the best possible demographic that will be influenced by donut commercials (cops, of course).
NJ got all the toxic waste dumps. You see, California drew the short straw and got all the lawyers.
Really? What frequency?
--
Damn the Emperor!
tropospheric ducting.
Ok, this is slightly OT, but speaking as someone who lives in Southern NJ, I would like to state for the record that no one around here speaks with that type of accent. We all pronounce Jersey with the letter R, thanks!
:)
Most people have a large misconception about New Jersey, especially thinking that it all looks like Newark, every woman has huge hair and long fingernails, and that none of us pronounce the letter "R". While this isn't entirely untrue (head up to Northern NJ to see what I mean), it does not describe the area of NJ being affected by the Boston signals. As I always say, they should split up Northern & Southern NJ, and combine the Dakotas.
Back on topic, I saw this story on the local news here tonight. It's a very big problem, as peoples lives can potentially be at stake. This is something we will be seeing a lot more of in the future; we already have frequency problems with 802.11, and now it seems that TV broadcasts will be continuing the trend.
I'm not gay, no dick goes in my ass
Only in California do you have to state these as two separate items
I work for a PBS station in VA, WHRO. We are currently being sued by a station WBOC-TV Salisbury, Md to stop the rollout of our Digital TV because it disrupts their signal on the Chesapeake side of the water.
From what I understand of the problem their were bad assumptions made by the FCC when it came to the digital signal.
1. That it would not bounce and doppler like analog signal does. Well it turns out it is even more prone to it than analog was due to the higher frequencies and watages involved.
2. That this would not affect a $Properly setup atena. Seems reasonable until you find out what the variable properly is. Apparently the FCC does not care about interference unless the atena is aligned directly towards the sending tower (that never happens and varies from channel to channel) and that it is not higher than 30 feet (one story home. Any deviation from that and it becomes your problem, not theirs.
This is also not the first case of this to happen. Their are previous cases in california and milwauke. Read more
here
This is going to crop up as more and more channels go digital. You will start seeing it reported more as stations start to battle each other. The sad part is that most likely the FCC will wash their hands initally and the airwaves will become as if the FCC does not exist.
Papa Legba come and open the gate
Ok, I'm the submitter. I see a few posts denouncing the "Joisey" reference. I'm from NJ. It takes a sense of humor to live in NJ. I know that SJ is vastly different from the smokestacks of Newark.
Am I the only person who lives in NJ with a sense of humor?
(oh, and for the record, I live between exits 3 and 4)
The One Rule Of Chess You'll Ever Need: Don't play someone who carries a kit in their bookbag.
I heard this once but never confirmed it: Is it true that Air Force One's broadcast system uses the same frequency as, and occasionally interferes with, garage door openers?
Just in case you would like to know what tropospheric ducting is.
[cop] breaker breaker we have a
*shhkt*
Johnny!. Don't you walk out on
*shhhkkt*
a caucasian male running down to
*shhkkt*
The LOVE boat...
*shhlkt*
suspect changing direction, now he
*shhhkkt*
was the president of the united states, saying
*shhhkt*
God dammit! where the hell is that
*shhkt*
sheik condom. Barely there for the most pleasure
=)
in girum imus nocte et consumimur igni
VHF / UHF Tropospheric Ducting Forecast Maps
These maps graphically display unstable signal areas.
Quote from the website:
The areas noted in the forecast have the necessary atmospheric conditions to produce tropospheric bending of UHF or VHF TV and radio waves. Tropospheric bending extends the range of stations well beyond their normal limit. Distant reception along straight line paths becomes possible..though the longer the path, the higher the Index required. The pursuit of distant stations is called "DXing".
The "real story" would be the article. Which contains the answers to every single one of your questions.
Under FCC regulations, any interference with official bands (IE, police, fire, ambulance) by a TV station is considered illegal by law and MUST immediately stop of be fined per day per channel that experiences the interference.
This occurred with one cable TV station over in one town that i stayed in. They had brought up another channel into their lineup using AINCENT cable equipment that generated a harmonic with the City police's repeater and caused massive interference with their communications. The city immediately moved and filed a complaint with the FCC on this and the Gov't submitted a court order stating that the cable company shut down ALL services until this issue was cleared up. The channel was immediately shut down and the station was shifted to another channel that was more clearer and did not cause any further problems.
First rule of holes; When in one, stop digging.
Make all the jokes you like about File Allocation Tables. See if we care. This is a Microsoft-bashing site after all.
I did get the impression that it is being forced down our collecive throats since it has not been adapted quickly enough by the market.
I feel that the regulations are being applied to the *wrong* industry. Wouldn't it be much better to mandate that all vehicles must be electrical or hybrid by 2007? As much as I like my car, I can see the advantage of such law. but TV phase out? for what? for Hollywood quality content that they have been withholding? :)
The links go to articles? Fascinating!
Why bother, I can have someone do it for me (in the freezing snow, rain, spiners, etc), it keeps my hands from smelling and it's cheaper than most of the country.
Do you cook your own hamburgers/steaks when you go out and eat? - no someone doe sit for you.
..........FULL STOP.
From the /. article header...
"The article seems to suggest that as more TV stations go digital, more small-town police radio will be affected, as the digital signal is significantly stronger than analog..."
Actually, the type of modulation (digital or analog) has little to do with the signal "strength" (which is a function of transmitter power output, transmission line losses, and antenna design and orientation).
Now, with that said, digital modulation, being much closer to a square wave than an analog voice signal, is much richer in HARMONICS than said analog signal.
I've lost count of how many times I've heard interference from digital paging transmitters bleeding into ham radio repeaters. The harmonics from the digital modulation mix with the transmitter's carrier, and that of whatever other transmitters happen to be on the same hilltop, and close to the same frequency range. It sounds awful, and it looks even worse on a spectrum analyzer screen.
The problem may be correctable through (as others have pointed out) better receiver design, in terms of filtering, and good installation practices being followed where the transmitter and antenna system are concerned. Good filtering and modulation techniques at the transmitter end won't do any harm either.
Bruce Lane, KC7GR,
Blue Feather Technologies
Geena Davis: "Easy, sport. I got myself out of Beirut once, I think I can get out of New Jersey."
Sam Jackson: "Yeah, well don't be so sure. Others have tried and failed... The entire population, in fact."
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
First there was the pumpkin PC, then the Dune book, and now a story that takes pertains only to NJ. I am officially suing slashdot for breach of contract.
You must be new here.
"Evil company X is threatening to restrict our rights! Let's all get together to stop--OOOH! SHINEY!!!" -- AC
Yes, our 'friends' at the FCC have been selling Digital TV channel 20 to police stations. The city bought those frequencies in '98. or maybe they trurned a band used for police into channel 20. Either way, they should have seen this comming. My question is what they were planning to do when Digital TV becomes more common.
It was me, I did it, I moved your cheese
Digital television won't affect small towns very badly. Many small towns are still on the 460 mHz band, rather than the higher bands that Digital TV will use. Remember, the FCC is clearing out the lower broadcast bands and moving everything up into the UHF and Microwave bands, where police don't do a whole lot of talking.
Trying is the First Step to Failing --Homer Simpson
A lot of innacurate information has been passed around here.
UHF communication frequencies generally go from 450-470 mHz and were fully populated years ago. What the FCC did is to allocate certain UHF TV channels to communications, in the 470-512 range; ie TV channels (not cable channels) 14-20 for communications use in certain areas. The areas in question are laid out in a plan, so that in some areas a certain channel is used for TV and and in some areas that same channel is used for communications.
This came about because in a given area you cannot have adjacent TV channels used by TV or they interfere with each other. Also, UHF TV was never really popular with broadcasters and many channels were loped off on the upper end (ch 70-88 as I recall).
Thus it is perfectly in accordance with the FCC plan to have Channel 20 allocated to TV in Boston and to communications in Southern New Jersy. Up to now, however, channel 20 was never used in Boston, it was empty and now has been allocated to digital TV.
Analog TV stations must convert to digital by a certain date (2006, but keeps slipping....). During the interim period, the station may transmit Analog on its present channel, and digital on the new channel. This is precisely what WCVB is doing. Eventually the station will be strictly digital on Channel 20 and the Analog VHF transmission will terminate.
East coast atlantic tropospheric ducting is common and radio hams and others are well aware of it; I am surprised the FCC did not take this into account when they allocated the channels. If I had to speculate, I would say that the FCC will require WCVB to reduce power, use a directional antenna or change channels - which may be tricky. This will be fertile ground for hordes of lawyers.
Yes, without New Jersey we wouldn't have...uhhh...hmmm...
:)
A place to put our toxic waste?
But seriously folks...
Jon Bon Jovi? Paul Simon? Allen Ginsburg? Jack Nicholson? Joe Piscopo? Kevin Spacey? Frank Sinatra? Meryl Streep? Ray Liotta? Michael Douglas? John Travolta? Elizabeth Shue (hubba hubba)? Jerry Lewis (ok, we could do without him...)
Thomas Edison? Irving Langmuir (Incandescent lamp)? Edmund Germer (Flourescent Lamp)? Lloyd Conover (Tetracycline)? James Hillier (Electron Microscope)? Donald Fletcher Holmes (Polyurethane)? Roy Plunkett (Teflon)? Lewis Sarett (Cortisone)? Vladimir Kosma Zworykin (Cathode-Ray Tube)?
First college football game (Rutger v. Princeton, 1869)? First organized baseball game? First pro basketball game?
Campbell's soup? Cranberry Sauce? Salt water taffy?
Electric guitar (Les Paul, 1940)? First submarine (1878)? First ferry (between Hoboken and Manhattan, 1811)? First brewery (Hoboken, 1642)?
No, I am not a Jerseyite. I live in Arizona and have never been to New Jersey. (Ain't the web wonderful? It's always good to learn new things - especially at my advanced age.) Of course, none of these things is enough to motivate me to vist.
War is Peace. Freedom is Slavery. Ignorance is Strength. - George Orwell or George Bush?
This is actually an issue the other way as well.
As the FCC forces digital broadcast and begins to sell off the UHF and VHF ranges for communications equipment....what will happen if a TV station is still broadcasting.
For instance, in San Diego the local Fox affiliate actually has their broadcast tower in Mexico (they can get a permit for a stronger signal there). If a nationwide carrier developes communications equipment uses that part of the spectrum...their equipment won't work in San Diego.
How will the FCC control 'foreign' signals?
I'm out of my mind right now, but feel free to leave a message.....
It's being forced on us because people are inherently dumb. People hate change (of just about any type) & this has hurt certain things. DTV/HDTV being one of them, other countries have something like it already (Japan) or are working on it (Europe & Australia).
I'm biased on the whole issue because I own an HDTV. HDTV is simly amazing. I've seen people watch an HDTV loop of various locations of the country for hours & this was a 10 minute loop (so it repeated for ~10 times before they could pull themselves away). It's also great for gaming as it lets games from a console system rival the quality of PC games, of course the only system designed to output in HD is the xbox but the next generation of consoles will most likely all support it...
we are all invisible unless we choose otherwise
The duct covered roughly 1600km LOS on a few watts. I don't know if that's a record, but it certainly impressed me.
Got time? Spend some of it coding or testing
I would RTFA, but the link is broken.
However, I find this somewhat surprising. Most police band radios operate in the 800MHz trunking band, which is reserved just for that purpose.
I didn't think the FCC was allowing digital TV anywhere near those frequencies - in fact that is why UHF TV channels 68 and up (IIRC) were taken out of service - to make room for the public service trunking band.
I would guess that what probably happened was that the station in question was mixing with another signal, and spattering into the police band.
In all probability, the cops didn't hear what the station was transmitting - Jersey is using Motorola Astro trunking, perhaps even digital mode, so the cops' radios would simply have said "this isn't the signal I was looking for. Move along."
Does anyone have a link to a cache?
www.eFax.com are spammers
It is being shoved down our collective throats! I have nothing against technology but there is something definitely amiss with this issue. HDTV and Digital Radio is not worth the price that we will have to pay and I am not just talking about money. Why is this such a priority for the FCC? There has to be money involved.... lots of money and we are the pawns. KEEP IN MIND... that this will edge out low-cost independent broadcasting because of the way the FCC has chosen to implement it. I am as tech hungry as the anyone but a B&W, 5" screen, analog TV for much of my watching needs is just fine. When HDTV if fully implemented I will no longer be able to use it. Digital braodcasting hands over control to the handful of huge media companies. They can control copying (recording), etc..... We have been sucked into DVD's. Which are nice but it controls copying of the media. We were sold on the digtial picture and sound but in reality it has giving the media companies control over copying. Something is wrong here folks. We should all step back and look very carefully at what we are giving up for a pretty picture. Is it worth it?