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White Space Debate Intensifies As Vote Approaches
Ars Technica reports that the debate between broadcasters and white space supporters has intensified after each side recently made inflammatory comments and suggested that science would vindicate their position. Several organizations are pushing to delay the upcoming white space vote, in part because it takes place on the same day as the US presidential election. We recently discussed Google's claim that a test of this system was rigged to fail. From Ars:
"The broadcasters contend that adjacent channel interference would be significant even at the 40 mW level proposed by Kevin Martin. In fact, they claim that such a device would interfere with digital television signals when the viewer is 25 miles from the television tower and the whitespace device is 10m or less from the TV set. At 50 miles from the television tower, a whitespace device within 50m from a set could allegedly cause interference. The broadcasters also want several safeguard requirements put on the technology that go beyond the new, lower-power transmission levels."
This page may help: http://en.wikipedia.org/wiki/White_Spaces_Coalition
"Maybe this world is another planet's hell"
Aldous Huxley
The transition of the U.S. to the metric system is on going, with the lesser-liked imperial units converted into the best-liked metric units first.
Yes, it's confusing. 10m is the standard test distance for various RF interference tests, which the FCC requires to be done with a method compatible to the CISPR specifications. That includes metric test distances, units of uV/m, etc. No doubt, that's why they used 10m separation, probably without even thinking about it. But for an American audience, they chose to use miles for distance to the broadcast tower instead of km because that's what we're used to.
Whitespace: (Microsoft, Google, Dell, HP, Intel, Philips, Earthlink, Samsung Electro-Mechanics) bring 10-100 Mb/s internet access over unused TV frequencies. (starting February 2009, US)
The above post looks like somebody forgot to take their meds, but just in case, check out "Gaussian fermentation". Googling it will give you upwards of 39,000 hits, but the most prominent are all for biology. It's a real term in papers on yeast or bacterial growth. So yes, once the yeast has fermented it, more of us than ever would like some kool-aid. Please strain it a little and let it age for a few hours.
Who is John Cabal?
Well, there's also technical issues like these. One of those pesky little problems that crops up when you have a bunch of unlicensed devices using the same frequencies as high powered licensed devices.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
[format fix] Excellent point.
I'm speaking from the point-of-view of the User, who is concerned about losing his ability to watch free television like Heroes, Lost, CSI, Smallville, 24, and of course the local news & weather. I speak of "interference" in terms of lost picture, and "whitespace" as something that doesn't really exist. Since I live in the Northeast, almost every channel is filled. There's only 3 open channels where I live; I don't see how WSDs are going to operate without causing me to lose my picture.
>>> At 50 miles from the television tower, a whitespace device within [160 feet] from a set could cause interference.
Unacceptable. If I'm trying to watch the Phillies match on WPHL-17, the last thing I want is for some brat with an Ipod to start broadcasting over top of 17 (because the Ipod believes it's empty), or neighboring channels 16/18, and instantly block-out my viewing of the World Series. ----- See my signature. Whitespace gadgets are fine. Just keep them off the TV band. I need my television; I like my television. According to a quick calculation, the addition of whitespace interference on TV channels would drop my receivable stations.....
From: ~19 channels (Baltimore, Philly, Harrisburg, Lancaster)
To: 5 channels (local market only)
Unacceptable. I just invested $300 on four DTV converter boxes, and another $250 on brand-new rooftop antennas. I don't want my investment to be a waste because it picks-up playboy.com datastreams instead of Heroes or 24.
The government is not your daddy. Its purpose is not to raid middle-class neighbors' wallets and give it to you.
The flaw with that reasoning is that there are NO unused television frequencies. The entire east and west coast is densely-packed and every channel from 2 to 51 is assigned a station. In my area (near Philly) there's only 4 non-adjacent open channels (2,3,4, and 25). That's it. And only one of them is useful for small devices (25).
The only region of the United States that is truly "open" is west of the Mississippi River & east of the California border. There are lots of empty non-assigned channels (mostly 21-51), but very few people live in this area.
In the U.S., the FCC allocates spectrum for, among other things, broadcast television. When the FCC allocates spectrum for television, they do not license adjacent channels in the same geographic market. They also do not license out the same channel to broadcasters in adjacent geographic markets.
Historically, spectrum was licensed this way due to concerns that, within the same geographic market, broadcasts on adjacent channels would bleed into each other and cause interference or that, in rural areas located near the boundary between geographic markets, broadcasts on the same channel would interfere with each other.
So, in a saturated broadcast market, half of all channels lie fallow as buffer zones between broadcasters. The White Spaces Coalition advocates freeing up these buffer channels which currently lie fallow for internet access.
I am not a lawyer. This post does not constitute any form of legal advice.
Except that nothing in the licensing requires it to be used for internet access, it's just general usage. This includes datacasting, bidirectional fixed communications (as occur in the 5.8 GHz ISM band now), and various class 15 usage.
Isn't that rebutted by basic physics? Both signals follow the simple inverse square law. A TV signal 50miles from the tower is 1/4 the signal strength of the signal 25miles, while a device 50m from a set is 1/25 the interference of a device 10m from a set.
You obviously don't know much about terrestial radio propagation. Depending on the heights of the transmitting and receiving antennas, the interventing terrain, amount and type of vegetation, it is easily possible that the received signal strength will fall off faster than predicted by a naive application of the inverse square law. Put another way, the inverse square law assumes that the transmitter and receiver antennas are in line of sight of each other, assuming "rabbit ears" on the receiver implies that the transmitting antenna needs to be above 400 feet for a 25 mile path and 1600 feet for a 50 mile path.
>>>in a thread where many readers may not be as familiar with this topic
Let's simplify it then. I currently get around 20 channels from local cities and from long-distance cities (Philly, Baltimore, Harrisburg). With Whitespace Devices polluting the TV band, I'll be blocked from watching Philly, Baltimore, or Harrisburg since the WSDs will interfere with long-distance reception. I'll only be able to get the local channels. From circa 20 downto 5. I don't find this acceptable.
The government is not your daddy. Its purpose is not to raid middle-class neighbors' wallets and give it to you.
Here's another useful site. It's a discussion forum, but it's filled with lots of RF engineers and hobbyists that are experts in the field.
http://www.avsforum.com/avs-vb/showthread.php?t=1048951
The government is not your daddy. Its purpose is not to raid middle-class neighbors' wallets and give it to you.
Dumbass answer. You use ALL the devices that are available (radio, tv, and if the power still works, internet). To handicap yourself by not using the tv with its visual-images of maps, storms, and tornadoes is stupid. ----- Also many communities in rural Oklahoma, Kansas, Colorado, Wyoming don't have any service except the VHF (read: very long-distance) TV. "Use the radio" is not a solution because the radio doesn't exist.
I stand by what I said before: "The last thing I want is for some Ipod to start broadcasting over-top or next-to my TV channel..... and block out the station while a major storm is blasting through, cutting me off from life-critical information."
The government is not your daddy. Its purpose is not to raid middle-class neighbors' wallets and give it to you.
The FCC has a rule that whichever service occupies a range of frequencies has first priority. Television arrived first in the 1930s, and certainly has first priority. The FCC is obligated to protect television transmission from interference of other devices.
If you reject that, consider the distribution of Heroes in HDTV. Which is more efficient?
- Eliminating television, and sending 30,000,000 copies to 30 million viewers via NBC.com?
- Keeping television and sending 200 copies to reach those same viewers via 200 terrestrial stations?
I think the answer is obvious. BROAD-cast of 200 copies of the show is far more efficient and logical than single-casting 30,000,000 copies. (Plus it's doubtful NBC.com could handle the required 500,000 gigabit demand of streaming Heroes in HD.)
The government is not your daddy. Its purpose is not to raid middle-class neighbors' wallets and give it to you.