FCC Rejects Cheap/Fast Internet Device

Tech.Luver writes "ABC News reports that a group of technology companies including Google, Microsoft, and Dell, have failed to convince the Federal Communications Commission of the utility of high-speed internet access via television airwaves. The FCC concluded the potential to disrupt consumer image quality was too high, in a statement released Wednesday. 'The technology companies say the unlicensed and unused TV airwaves, also known as "white spaces," would make Internet service accessible and affordable, especially in rural areas and also spur innovation. However, TV broadcasters oppose usage of white spaces because they fear the device will cause interference with television programming and could cause problems with a federally mandated transition from analog to digital signals in February 2009.'"

Comments

Interesting

[tttonyyy]

Interesting the timing of this article given Ofcom's recent approval of Ultra Wide Band for consumer devices in the UK.

http://news.bbc.co.uk/1/hi/technology/6938941.stm

FCC happens to be right on this one...

[Ancient_Hacker]

Putting wireless internet on the freed-up TV channels is a particularly poor use of the spectrum. Each TV channel is only about 6 MHz wide (4.5 plus some guard space). That would accomodate maybe 50 million bits per second of service, across the propagation range of VHF and UHF, which depending on power and weather, can range from a few hundred meters to several hundred miles. If you use a few hundred watts you could cover a few square miles, but so can the current Wifi channels. Covering a large rural are is impractical as you'd need many watts of power transmitted at the user's end, and only a limited number of users could be handled.

Re:FCC happens to be right on this one...

[Bluesman]

"Covering a large rural are is impractical as you'd need many watts of power transmitted at the user's end, and only a limited number of users could be handled."

Huh? How big of an area are you talking about? Cell phones don't transmit with many watts of power, and they still work in rural areas.

The UHF TV stations are within 100MHz of commonly used cell phone frequency ranges, so the propagation, antenna length, and power requirements would be very similar.

Being that the user would be based at home, and not limited by the size of a mobile phone and battery, there would be more than enough power.

Re:Interference Prevention

[Bluesman]

"The level of signal redundancy (using Viterbi encoding) combined with the forward error correction (FEC) mechanisms introduced in the signal, practically reduce the risk of interference to none."

I'm sorry, but that's just misleading.

In any channel transmitting digital data, you have a certain bit error rate (BER). Using error correction techniques, you can improve the performance of the channel such that the BER is equivalent to that of a channel with much less noise, or much higher transmit power, or much higher antenna gain. Error correction provides gains that you can measure in decibels, just like an increase in transmit power would.

But a dB loss is a dB loss, it doesn't matter if it's due to weather, interference, etc. If interference causes a dB loss over and above what the channel was designed for, you lose more bits than expected, and quality degrades.