 MrMoodyFree range slavePremium
join:2002-09-03
Smithfield, NC | No I still don't think it's possible to make these things so they don't interfere with distant broadcasts, and even if they do, once the floodgates are opened, substandard, interfering devices will eventually find their way into the market. It's tough enough to get a clean digital TV signal as it is. Therefore I hope the FCC continues to do its job and protect us from them. Let them find some other band to steal, or license channels geographically.
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Electile Dysfunction: the inability to become aroused over the choice for President put forth by either party. |
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 tobyTroy Mcclure
join:2001-11-13
Seattle, WA | yep! |
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said by MrMoody:I still don't think it's possible to make these things so they don't interfere with distant broadcasts, and even if they do, once the floodgates are opened, substandard, interfering devices will eventually find their way into the market. It's tough enough to get a clean digital TV signal as it is. Agreed. This has the potential to destroy even medium range digital TV reception. How will a white space box inside a house detect the signal from a distant station that the neighbor picks up with a high gain antenna in the attic or on the roof?
One item I have not seen discussed is how these white space communications will detect analog stations? After the full power station analog shutdown, there will still be 1000s of low power (LP) stations and translators (TX) broadcasting in analog. The conversion plan for the LPs and TXs has still to be finalized, but the reported plan is that they will have until 2012 to go all digital. They should table these devices until all TV broadcasting is digital. Which still doesn't address usage along the Mexican border as Mexico currently has a 2020 or so final digital conversion date for TV broadcasts. |
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i suggest that you figure out what they want to do. a 'white space' device would NOT transmit in a frequency band already in use. so i don't know where you pulled this BS from, but i have an idea of it would make it harder to tune to a DTV channel. from my understanding, the atsc performs fairly well with interference, assuming the pilot carrier is intact, if it isn't, well that channel is pretty much killed for any reciever. again, i suggest you figure out that 'white space' and 'white space' devices are before you spread your FUD. |
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EPS
join:2008-02-13
Hingham, MA | A 'white space' device is not SUPPOSED to transmit on a frequency band already in use. The problem is the reliability of the systems that detect whether said spectrum band is in use. |
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MrMoodyFree range slavePremium
join:2002-09-03
Smithfield, NC | reply to cornelius785
said by cornelius785:a 'white space' device would NOT transmit in a frequency band already in use. 1. I'm pulling this from my knowledge and experience as a licensed radio amateur. I don't believe it can reliably tell if a frequency is in use from 40-60 miles away requiring a high gain antenna high in the air to see it (UHF is not much better than line of sight), with the whitespace device sitting at ground level with a rubber stub or internal antenna with no gain or less. FCC tests to this point have borne this out. There's only one way to reliably tell: have the FCC license them geographically.
2. It doesn't need to transmit on a frequency in use to cause interference/signal loss on close by frequencies. Enough signal overwhelms and desensitizes the receiver. The signal levels required to send data for miles far exceeds that used by current Part 15 devices. »www.mstv.org/static.html
3. Everyone wanting this is wishing for things that are NOT going to happen even if it goes forward. TK and others may be evil, but they are still right. The best you will get is another costly, limited EVDO type mobile system. Microsoft & friends just want to get into the cell business on the cheap. Competition for wired internet: no, not enough bandwidth for large numbers of customers, it will be just like satellite. Wired service will always be far superior. Rural service: no, the providers will only be interested in densely populated areas, just like everything else, and again it will be no better than satellite even if the service did reach them.
I'm all about rural internet, we seriously need it, but TV band radio service is not the answer.
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Electile Dysfunction: the inability to become aroused over the choice for President put forth by either party. |
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| reply to cornelius785
said by cornelius785:i suggest that you figure out what they want to do. a 'white space' device would NOT transmit in a frequency band already in use. That's the kicker, determining what frequency isn't in use. It can be difficult for a device to accurately predict what other receivers are actually receiving. If the whitespace device has a lower receiver sensitivity and/or antenna gain compared to a potential local interference victim, it could make wrong frequency selection decisions. If the frequency selection algorithm is also frequency database-based as I seem to recall was mentioned back when this was originally thought up, that would help though it's not foolproof.
I don't think the original post is FUD, he has some valid questions and observations. Anytime you have inexpensive consumer grade devices that are unlicensed and unidentified operating in a band with a primary licensed service with receivers that have no way to assert their usage of a frequency, you're going to have significant technical issues to address. Unfortunately this is what happens when you mix two very different services. |
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PDXPLT
join:2003-12-04
Banks, OR | reply to MrMoody
said by MrMoody:I still don't think it's possible to make these things so they don't interfere with distant broadcasts. 'doesn't matter. Distant TV broadcasts (i.e., signals received outside the Service Contour for the station in question) are entitled to no protection under FCC Rules. They can be interfered with by local full power stations, by local Class A and LPTV stations, by Part 74 BAS's, and by unlicensed devices (there are legal unlicensed devices operating in the UHF band now - remote controls. Not to mention a whole bunch of illegal ones: most wireless microphones).
As I've noted previously, there are already several hundread thousands of unlicensed devices operating in the TV sprectrum already, albeit illegally; namely, wireless microphones in use by those who do not qualify to obtain a license (which is most people). Yet the sky hasn't fallen, and people still get their TV just fine. Users tend to pick the channels where they aren't going to be interfered with by TV stations.
The NAB and the Society of Broadcast Engineers have complained a couple a times to the FCC about these illegal devices, but haven't been serious about because interference cases are few, and microphones aren't competing for eyeballs (unlike what Google has planned).
quote:
Let them find some other band to steal
Radio spectrum in the U.S.A. is owned by the American people, and managed by the FCC and NTIA. No one one would be "stealing" anything. |
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i dont know if this is the answer or not ,but its a damn shame that everybody cant get real broadband.im 5 miles out of town dsl stops 1700 feet from me.cable will never extend to me without me paying 10,000 dollars for it that also stops 1/2 mile from me on the same road.I have hughes satt that is very expensive and not better than dialup speed half the time.if tellco will get off their ass and add dslams then we would not even need this,but something is going to have to be done to provide real broadband to everyone,mabey they just use the ham bands too it is not used for nothing but bs.I have been in public safety for 20 years and have never used or have ever seen ham used for nothing but wannabe storm chasers or private conversations,and by the way i am a ham operator myself and would gladely give it up to real broadband |
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| another thing if it wasnt for all the crybaby ham operators we all would have broadband over power lines and everybody with power could get it,but they had it shut down thanks |
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| said by pissed :
another thing if it wasnt for all the crybaby ham operators we all would have broadband over power lines and everybody with power could get it,but they had it shut down thanks
BPL shut BPL down. The hype didn't live up to the reality. The fact that you say we would all have BPL and "everybody with power could get it" shows you don't know too much about it. |
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MrMoodyFree range slavePremium
join:2002-09-03
Smithfield, NC | reply to PDXPLT
said by PDXPLT:doesn't matter. Distant TV broadcasts (i.e., signals received outside the Service Contour for the station in question) are entitled to no protection under FCC Rules. Does matter. When I say 'distant' I don't mean out of contour, I mean any station over about 25 miles away, and there are plenty of contours which go a lot farther than that.
All those unlicensed devices you name (legal and illegal) are operating at very low power with a range measured in feet, and are subject to Part 15 rules; if someone complains you must correct the interference or stop using the device. Most so-called "UHF" devices, including remotes and portable phones, are in the used-for-little-else 902-928 MHz amateur band, or many older ones (pre 1990 or so) were in the 450-470 MHz shared commercial band. The highest UHF TV channel is 801 MHz (693 MHz after Feb.) and the lowest is 471 MHz. These devices don't interfere with TV because they are outside the TV band. Wireless microphones (the high end ones requiring licensing) aren't generally being operated for any amount of time in residential areas either.
Show me one device, in common household use, outside of license-required microphones, that operates in the UHF TV bands of 470-608 & 614-806 MHz, which IS EXACTLY where the white space boxes will be (up to the new end at 698 MHz anyway). No guessing, show the frequency. Analog TVs are VERY sensitive to this sort of thing, so these bands weren't used for this sort of thing.
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Electile Dysfunction: the inability to become aroused over the choice for President put forth by either party. |
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| reply to PDXPLT
said by PDXPLT:said by MrMoody:I still don't think it's possible to make these things so they don't interfere with distant broadcasts. 'doesn't matter. Distant TV broadcasts (i.e., signals received outside the Service Contour for the station in question) are entitled to no protection under FCC Rules. They can be interfered with by local full power stations, by local Class A and LPTV stations, by Part 74 BAS's, and by unlicensed devices (there are legal unlicensed devices operating in the UHF band now - remote controls. Not to mention a whole bunch of illegal ones: most wireless microphones). Can you show me where this rule is? I'm not saying you're wrong, I'm just not familiar with the rules specific to protection being extended only to a certain contour. I was thinking the same thing MrMoody wrote in regards to the Part 15 harmful interference rules. |
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| reply to pissed
said by pissed :
,mabey they just use the ham bands too it is not used for nothing but bs.I have been in public safety for 20 years and have never used or have ever seen ham used for nothing but wannabe storm chasers or private conversations,and by the way i am a ham operator myself and would gladely give it up to real broadband
Your post would have some credibility if you provided a callsign, gave some indication you've experienced something more than 2 meters or are actually active in amateur radio, and used at least fourth grade punctuation and grammar. |
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| now why would i do that im not stupid |
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| reply to rf_engineer
im not a typer,tried to use spell check but wouldnt work due to hughes net 5pm to 12am throttle down to dialup speed |
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| reply to rf_engineer
it worked fine where it was tested,ham operators said it was interfering with their radios bs.thats what pl,s and squelch is for |
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| reply to rf_engineer
said by rf_engineer:That's the kicker, determining what frequency isn't in use. It can be difficult for a device to accurately predict what other receivers are actually receiving. There is another problem and that is the scarcity of unused UHF channels in the more crowded markets such as the mid-Atlantic region or LA. Has Google and the others taken a hard look at how many unused UHF channels they will be in some areas? Not many if you take the Service B contour and the reception range outside of that. Will these devices be allowed to use the Land Mobile band channels that are assigned to UHF 16 to 19 in some cities? WPVI-DT ABC 6 in Philadelphia will be on VHF 6 next February because of the lack of a suitable UHF channel they could use.
If their plan is to use the unused UHF channels, people may be in for reality check once they try to field these in some areas. If Google, Microsoft and the other backers wanted to provide for new open broadband communication systems, they should have petitioned Congress and the FCC to set aside several of the 6 MHz UHF channels that were up for auction as public white space bands. Of course, this would have reduced the funds raised from the auction, but Congress might have been persuaded that it was in the public interest (if enough lobbying money was put into it). |
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| reply to pissed
said by pissed :
it worked fine where it was tested,ham operators said it was interfering with their radios bs.thats what pl,s and squelch is for
{sigh} 
PL is only used on VHF and UHF repeaters. BPL doesn't affect UHF repeaters or 2 meter VHF and 6 meter VHF repeaters are few and far between. And regarding squelch, you can't squelch out a 20dB over S9 interfering signal on HF.
Again, your words tell me you've never done anything more than 2 meters, and your view on BPL is quite uninformed, especially if you're a ham, which I really doubt. The fact is BPL did interfere and it's documented. Do some research about BPL and ham radio. |
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| reply to pissed
said by pissed :
now why would i do that im not stupid
You can PM your callsign to me since you're not stupid. If you're in the US, they start with a K, W, N, or A, one or two letters in the prefix, a number, and then one to three letters afterwords. Check QRZ.com or the FCC ULS to make sure it's a valid and active callsign. |
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