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This is what happens when one confuses "random" with "profound."

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Forgive my ignorance. Ham radio uses low frequency spectrum, right? And sometime those signals can bounce of the clouds and go half way around the world. But it is relatively low bandwidth. And not secure, so that everyone can hear the one person speaking.

But cell phones sometimes drop out when you go a couple of miles outside the city... but they are secure -- you can talk one-to-one and be relatively certain you have a secure line.

And digital TV uses high frequency spectrum because it is easier to get a lot of information... and advertisements... in there.

Compression and intelligence are basically synonymous.

Why isn't it possible to create a cell phone network using ham radio signals?

Ok it's low bandwidth. We are intelligent, we will come up with ways of compressing the information so that it is more real-time and more real-space.

And if there was a platform for making that happen then it would be more likely to happen.... we would get more intelligent.

The competitive strugle for more bandwidth space seems to me to be tragically reminiscent of the competitive struggle towards flight that led to Alexander Graham Bell inventing ailerons and Wilbur Wright dejectedly dieing of tuberculosis or whatever.

JesusHChrist, Sep 15 2012

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       //Ham radio uses low frequency spectrum, right?//   

       Ham radio uses lots of frequency bands, from 1.8 MHz to over 275GHz. Some of the most popular bands are the 2 meter band (144 MHz) and the 70 cm band (440 MHz) for local, and the 20 meter band (14 MHz) for distance.   

       //And sometime those signals can bounce of the clouds and go half way around the world.//   

       Sure, using an antenna as tall as a house, or enough power to cook a steak.   

       //Why isn't it possible to create a cell phone network using ham radio signals?//   

       Lots of reasons. For one thing, cell service is inherently short range. You need to be able to hit a cell tower in order to carry on a conversation. Any farther than that is wasted energy, and starts to cause interference with other signals on the same frequency that are trying to reach nearby towers. One of the ways that they multiplex so many conversations on relatively narrow frequency bands is by reusing frequencies many times across large areas. So you don't really /want/ your signal to go too far. The area your signal reaches increases with the square of the maximum distance (i.e. the radius), meaning that the amount of usage that can be obtained out of a given frequency decreases exponentially with the range of the signal.   

       Another problem is that an efficient antenna for a given frequency should be as close as possible to half the wavelength of the frequency. For 900MHz cellular, this is about 6.5 inches, and for 1900MHz, it's about three inches. For 10MHz, it's about 50 feet. For the sort of frequencies you're talking about, a cell phone sized antenna would be all but useless. You might get /some/ signal out of it if you dump a whole bunch of power into it, but you'd probably still obtain better range by using a higher frequency signal anyway.   

       //We are intelligent, we will come up with ways of compressing the information so that it is more real-time and more real-space.//   

       There are some hard and fast limits to what can be done. The Nyquist limit puts an upper boundary on how much information can be digitally transmitted by a given signal. Also, it's mathematically impossible to losslessly compress data past a certain point, and there's an upper limit to how much loss can be tolerated before the signal degrades to uselessness; we're already pushing that limit with existing technology. There may be room for a bit of improvement, but we're talking small percentages here, not the orders of magnitude that this idea would require (even if it were not for the technical infeasibility of transmitting such signals from a cellphone).
ytk, Sep 15 2012

       [ytk], please forgive me, but you had me on your side until paragraph six. Just hit enter twice every so often.
normzone, Sep 15 2012

       Exactly what [ytk] said.   

       There are a couple more rather abstruse factors, but essentially that anno neatly covers all the relevant arguments.
8th of 7, Sep 15 2012

       Jesus H. Christ. What a lot of beating about the bush. Aliens have had this licked for aeon's. Just drill a hole in the back of the nut, stick an aerial in and your in business with telepathy.
Lesser Spotted Kiwi, Sep 15 2012

       [lsk] true, true   

       [ytk] TY
JesusHChrist, Sep 15 2012


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