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WiFi Signals In Between Television Frequencies
compgenius3 writes "The FCC unanimously voted today to allow wireless providers to use the frequencies between television stations to broadcast WiFi in rural areas. Broadcasters argue that this will cause interference on television stations but the FCC chairman says otherwise."
Update: 05/18 23:40 GMT by T : compgenius3 points out NAB president Edward Fritts' skepticism of the plan, as reflected in this press release citing fears of intereference to over-the-air broadcasts.
Happy Trails!
Erick
http://www.busyweather.com/
This article
http://www.busyweather.com/
They are http://www.newsmax.com/archives/ic/2004/5/14/21052 8.shtml
But TV broadcasters oppose the proposal. They argue that it would interfere with over-the-air television signals for millions of people.
Setec Astronomy
Yes, channel 6 is 83.25 Mhz, channel 7 is 175.25 MHz...channels 2-6 are 'VHF-LO' and 7-13 is 'VHF-HI'
UHF starts at channel 14 @ 471.25 MHz...
See this page for more info.
Have you driven by one lately? There are a surprising amount of satellite dishes at some of them. Even before all of the DirecTV and Dish Network varieties there were those behemoth dishes sitting next to the cable spool/picnic tables.
It's only for rural areas which are econnomically impossible to be commercially provided with the Internet over wired networks. As an example take that a lot of people who actually had cable TV switched to satellite TV just because cable had such low quality and so many outages, that regular aerial seemed better than that. Basically decision subsidizes rural area ISPs without giving them any money (like it was with the case of telephone and electricity) - government loves it, public thinks it's great, and ISPs have to play along. Not that without substantial increase in costs they will be able to do anything, because 802.11 goes normally for about a 100-200 meters, and typical distance to your ISP in rural area will be about 10-20 miles.
the FCC is totally clueless in this iteration. there is a reason the space between TV channel assignments is called "guard bands," it keeps interference from generating third signals in the receivers (heterodynes, if you want to check the engineering details) that fall in the intermediate tuning circuits and mung up the signal. heterodynes with a strong local signal can wipe a whole TV out. and since there is no shielding worth noting in a commercial set, this means whoever puts up a wi-fi is responsible for zoning out the neighborhood.
there would of course be little impact if the darned TV sets were shielded from RF interference. they aren't because it would cost a few quarters to do it, at worst case $5 to the retail buyer when they wave plastic at the best buy counter.
if you have tried to put a cable TV or satellite box under your TV set, you know what I mean; screens full of little electronic worms.
unless FCC mandates retroactive shielding and all future sets being shielded before sale, this will become a nightmare.
ex-broadcaster, ex-ham, ex-recording engineer, I know interference is real and ugly. don't make any more.
if this is supposed to be a new economy, how come they still want my old fashioned money?
I live in a rural area and there is like four over-air broadcasters. That leaves tons of spectrum left for broadband.
OFDM is used for over-the-air digital TV, and it is fairly robust to nasties. A digital receiver can eliminate interference to an extent through adaptive processing, or compensate for it through FEC, but you can always get to a point where interference and/or noise will wonk a signal (eg, sun outages in geostationary satellite applications).
(S(SKK)(SKK))(S(SKK)(SKK))
The TV stations aren't pissed off at the FM stations because TV and FM don't have to share any spectrum, and FM is also a licensed and regulated service. There is a nearly 100 MHz break between channels 6 and 7 used for FM, Aircraft navigation and communication, and various other things.
This is different because it proposes using 'unused tv channels' to carry unlicensed signals. (Take note that this is also different from what is implied in the headline...this is not 'the space between TV channels,' it is full channels.)
"Brilliant observation of the day. Please mod up the parent of this reply."
Mod parent down for cluelessness and knee-jerk conpiracy theories.
As another poster pointed out, there is almost 100 MHz between channels 6 & 7, with the FM broadcast bands occupying about 20MHz of that. By comparison, each TV signal occupies 6MHz. There is little direct intereference because of channel spacings.
More importantly, one the major concerns about Wi-Fi is probably that the devices will operate under Part 15, where the users are not required to have a license from the FCC. Instead, they'll bitch and complain and not understand that they must not interfere with other licensed services and must accept any intereference they receive.
Things to do today: See list of things to do yesterday
The cable environment is much more controlled than the over-the-air environment.