Talk:White spaces (radio)
|This article is of interest to the following WikiProjects:|
Do I understand this correctly, the question is either Internet Broadband across the United States or the possibly restricted use of wireless microphones?
I'll quote Spok from Star Trek's the Wrath of Khan "The needs of the many outweigh the needs of the few."
Is there a need for a separate White Spaces Coalition article? Neither article is long, there is some duplicative material, and as far as I see the coalition exists only to contest and exploit the resource. Jim.henderson (talk) 02:39, 12 November 2008 (UTC)
Accuracy / Confusing?
I think the article is misleading, but I'm not sure enough of my facts to directly edit it.
What I think is that white spaces refers to the unused space in the digital TV spectrum. Let's say that a local market has digital TV stations numbered 3, 7, and 14. This means that there are empty 'channels' that could be used for white space transmission of data.
The article at several points seems to imply that the 'white space' refers instead to the space opened up by the elimination of the old US analog channels. However, this is not what I have heard. My understanding is that this 'open' space has been claimed. It was auctioned by the FCC for use by wireless providers and Verizon was the big winner. Therefore, I believe the only white space is in the spectrum set aside for Digital TV that is not currently used by any TV station. This white space would exist at different frequencies on a market by market basis. It all depends on what channels are broadcasting in, say Chicago versus Atlanta.
If you read carefully enough you can see that at times the article does indicate this interpretation. However, at other times it seems to imply that white spaces refers to the spectrum vacated by analog TV (and now owned by Verizon and others).
However, as I said, I'm not expert enough on this to directly edit the article. I would appreciate the comments from someone more knowledgeable. —Preceding unsigned comment added by 22.214.171.124 (talk) 05:33, 28 January 2010 (UTC)
- Your understanding of the term "white space" as it is being currently used in an RF spectrum context is correct -this article is in need of a re-write. The article might also point out that these recent FCC rulings and proposed re-allocation of the DTV broadcast spectrum (including white space utilization) has become quite a contentious issue. —Preceding unsigned comment added by 126.96.36.199 (talk) 19:02, 5 January 2011 (UTC)
Est-ce qu'il y a d'information canadienne
Are there any analogies to canada?
Don't forget about ham radio and other commercial/government frequencies!
the frequency range needs to be edited so as not to confuse people that 54mhz-690mhz is only used for television and nothing else. broadcasting ranges in the us are 54-72,76-88,174-216,470-608,and 614-806. theres more but for vhf/uhf that is all that is allocated.
This article erroneously states
...the switchover to digital television frees up large areas between about 50 MHz and 700 MHz. This is because digital transmissions can be packed into adjacent channels, while analog ones cannot. This means that the band can be "compressed" into fewer channels, while still allowing for more transmissions.
There is quite a bit of disagreement on this point especially with regard to white space utilization.
After the digital transition only the frequencies between 700MHz and 806MHz were freed-up for other uses. The 6MHz bandwidth per channel, which was the same amount allocated for analog TV broadcast, is still required for full high definition broadcasts (1920x1080i, 5.1 audio channel, with a 19Mbs transport stream). Several stations (most notably ABC & Fox affiliates), choose to broadcast 1280 x720p resolution which permits added lo-def. sub-channels (and perhaps dual use 1280x720 channels), but all digital broadcast channels are still 6MHz wide and still susceptible to both adjacent and co-channel interference (8VSB transmission hasn't changed the basic laws of physics). As a result the FCC is still regulating the ERP, frequency/channel allocation, and geographical spacing of DTV transmitters around the country.
(WARNING POV): Interference is what makes unlicensed use of this white space so perilous. Even low powered devices with frequencies designed to work in some locales could easily find their way into regions where those frequencies are in use by broadcast DTV, or perhaps even fire, police, EMS, etc., causing local interference with those transmissions. There are some 802.11N wi-fi systems which currently have an advertised max. range of 2,000 meters (over a mile). I could imagine someone mounting one of these on a mast looking for local open hot spots and interfering with TV or radio reception in the whole neighborhood. The initial FCC rules for white space devices required a frequency scan every minute to detect existing transmitter use but their final rules dropped that requirement which, in many peoples' mind, will lead to "spectral anarchy". —Preceding unsigned comment added by 188.8.131.52 (talk) 20:22, 5 January 2011 (UTC)
Cambridge, United Kingdom tests
On June 29, 2011, One of the largest commercial tests of white space Wi-Fi was conducted in Cambridge, England. </Quote>
This is a slight overstatement! On the 29th June a launch event was held to launch the Cambridge White Spaces trial, at which a couple of demos were carried out. There are also (apparently) two rural broadband links set up. The trial operates under a temporary spectrum licence. As far as I know it is not commercial and is just starting.