Why are radio waves good for transmitting data over large distances?

Answer 1

Because they can be reflected by the ionosphere of the earth's atmosphere and thus can be send to longer distances. There is one more benefit that in case of shortwave bands, the attenuation is low than at the MW or FM frequency. Attenuation is loss of signal strength as the waves traverse the space.

Answer 2

Well, let's think about a few other things that could be used to communicate

from place to place:

String with tin-cans or ice-cream-cups on each end:

Low-quality communication. Works only when string is tight and dry. Capacity of

only one voice per string. Analog only, no digital. Hard to install around corners.

Hard to build repeaters to "boost" signals over long distances.

Wires:

Rugged, excellent high quality communication. Can carry maybe 30 voice-quality

channels, or 1 or 2 music-quality channels, or 1 or 2 DSL internet channels, all

on one pair of wires. For more than that, you have to run more wires.

Many such wired networks exist right now. They're called "telephone companies".

Every time you want to add communication with 1 new person, you have to run

new wires to him. That's why, in many countries around the world, cellular service

is growing much faster than "land-line" service ... if you want a phone, you don't

have to wait until the telephone company can bring wires to your house.

Optical Fiber:

Rugged, excellent, high-quality, high-capacity communication. Can carry more

voice-quality, music quality, and high-speed data channels than you can imagine,

all at the same time.

To get fiber to reach everyone, new cables have to be physically hung from

poles or buried in the ground, all the way from some kind of central office to

every individual house ... essentially building the whole telephone network all

over again from the ground up. They're working on it, but it'll take some time.

Wouldn't it be much easier if we had a way to communicate over distances

without installing some physical "pipe" every inch of the way between the end

points ... without string, wires, fiber, etc., just a jump, from here to there ? !

Well, here are a few possibilities:

Sound:

Put up big rock-band speakers on top of a tall building in the middle of town,

and broadcast the music, news, weather, and commercials through them.

Anybody who lives close enough can hear it clearly, just like radio, but they can

do it with the receivers they were born with, and they don't need any special

equipment.

Problems: => Thunderstorms interfere with reception. Just like AM radio, only worse.

=> No way to separate, just like at a loud party. More than 3 or 4 stations in town,

nobody can receive anything, because of extreme "co-channel interference".

=> Limited capacity: 1 audio channel, no digital, all one-way, no return-channel.

=> Nobody gets any sleep. No ON/OFF switch.

Visible light:

Good idea. "Fiber without the fiber", just a beam of modulated light.

Works fine. Until rain, snow, birds, or a tall truck blunder across the beam.

Radio:

Without going into a lot of detail or belaboring the point ... you pretty well know

what's being done with radio now and what it's capable of.

If you feel that any of the other methods considered above is a more effective

way to accomplish our communication, or you know of some other method that

hasn't been mentioned that can do the job better, faster, cheaper, and easier

than radio, then please! By all means! Let's hear about it.

Answer 3

Short wave radio does not need communication satellites. It can reflect off the ionosphere (especially at night) going long distances on each skip.

It is microwaves that needs communication satellites as it travels only in straight lines.

Answer 4

The best reason I can think of is: They cover the distance

from here to there faster than anything else ever could.