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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."
... Because INTERCAL is just too user friendly.
Today's Sesame Street was brought to you by the number e.
Perhaps a short explanation of what "white space" is in this context in the summary might be helpful?
Yes I even RTFA to try to figure it out but it already assumed prior knowledge as well.
What's with the mixing of units? Use either 50 miles and 50 yards, or 80 km and 50 m. Mixing imperial and metric units like this, will probably cause http://tech.slashdot.org/article.pl?sid=08/10/25/1449212#the test devices to explode.
As a representative of UltraProfitCom, I must point out that the use of 40 mW transmissions over the whitespace could raise very unpleasant technical issues. For example, it could damage the profitus of the entrenchedplayerus. It may also vastly increase the alternativus that individuals have for data transmission containing dangerous features like competitiveservicus. Left unchecked, these transmissions could also increase the convenientus that people have to do deal with. Clearly, it should not be done.
Information theory is life. The rest is just the KL divergence.
"Nobody screams louder than somebody whose subsidy is being cut".
Now, it is politically popular to think about that statement only in the context of bloated, black, cadillac-driving, welfare queens and their giant broods of fatherless criminal children; but such a type, if it exists at all, is chickenshit in terms of real subsidies. Consider rather the broadcasters who have made huge amounts of money, and acquired a great deal of influence, thanks to a government granted monopoly over big chunks of our spectrum.
Tabs
-Dave
Whitespace? Why do they have to be so racialist?
Since this is actually my research area, I thought it would be good to give some input here. Part of the controversy is simply due to the language used.
1) "Whitespace" is used in two subtly different senses by people that causes some confusion.
A) From the perspective of the potential new user of the spectrum, a "whitespace" is where the band is clean and so it could be used to deliver relatively high data-rate without having to put out too much transmit power relative to the desired range.
B) From the perspective of the existing user of that spectrum, the above perspective is troubling since it seems to ignore the externalities imposed by interference to others. The existing users' perspective is better captured by the idea of a "spectrum hole" that reflects where a new user could safely transmit without significantly bothering too many existing users. However, spectrum holes are also called "whitespaces" and this causes confusion.
The apparent weasel words "significantly" and "too many" above reflect a real set of engineering-tradeoffs underneath that must be navigated at least partially at the political level.
2) "Interference" is used by people in two different senses and this also causes confusion.
A) Interference is a purely technical concept that describes how performance degrades for a receiver with the introduction of additional signals into the environment. Here also there is some ambiguity because of a distinction between what would necessarily degrade performance even for an ideal or well-engineered receiver and what is feared to degrade the performance of possibly poorly designed or shoddily built receivers.
B) Interference is also an English word that encompasses uses like "you're interfering with my business model by offering a competing service."
Keep this in mind as you read any general articles about this subject. There are real tradeoffs involved in this topic, but sometimes the language used obscures or obfuscates them rather than making them clearer.
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?
Why not read a op-ed piece from someone who both knows about electrical engineering and doesn't have a vested (i.e. profit) interest in the outcome one way or the other?
EDN editor Paul Rako wrote this edotiral recently, "White spaces and black hearts".
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.
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.