Why aren't we using satelites for Cellular telephone antennas?

Question

At present we are using space for everything from crop surveys to traffic patterns. I'd like to know why the same technology can't be used to improve communications at a minimum cost?

Answer 1

Satellite phones have high power and are expensive, plus the satellites in orbit don't have enough bandwidth to carry all the calls.

Answer 2

2

Answer 3

They are too far away. Radio communication depends on the antenna being big enough, and the receiver being close enough to the transmitter. Actually, one cell phone project did use satellites; you had to set up a portable antenna and aim it properly to get the thing to work. Demand for this product proved slight and the company went bankrupt.
Another factor is time. This is not so much an issue with low orbit satellites, but the round trip time to geosynchronlus satellites is a definite nuisance when attempting communication. I can always tell when, on the television news, the remote feed is via a satellite link: the reporter stands there for several seconds after being introduced before saying anything.

Answer 4

(1) Because it would take a lot of enengy to have the signal from the satilite to reach the cell phone.

(2) It would take a whole lot of energy for your phone to send signals to the satilite (and you thought you battery charge didn't last long enouph before)

(3) When ever it is really cloudy or stormy your phone service would not work. Same thing if you are indoors (try using a GPS device in side)

(4) The satilites would constantly be going in and out of range, so your phone would spend a lot of time ( and enengy) searching for a signal.

(5) Sending up a network of satilites is very very expencive


Those are just a couple of reasons why it is not a common thing.
You can purchase a satilight phone(it does exist) The plan is very expencive, the phone is very expencive, the battery is large and heavy, and the reseption and signal strength is not that good.

Answer 5

I'm a communications satellite engineer, so I'll try to dispel a lot of myths surrounding satellite phones.

Satellite phones today are NOT huge, unwiedly phones the size of your head. The most recent generation of satellite phones, used with the Thuraya service ( http://www.thuraya.com ) look like the ugly phones everyone had 4 years ago.

This is actually really impressive since these phones are talking with geosynchronous satellites - which fly at an altitude of 22.2 thousand miles above the Earth. However, because the satellite is so far away, you need to be outside with view of the sky in order to connect your call directly with the satellite. Booster towers may be able to allow you to connect from inside - your phone connects with the tower, and the tower connects with the satellite.

Another downside of these phones is the signal delay time. These satellites are so far away, it actually takes about a quarter second for the signal (which is moving at the speed of light by the way) to go from the ground, up to the satellite, and back down.

Satellite phones have not caught on in the US because we already have an established network of cell phone towers, so we really don't need it. However, in other undeveloped areas of the world, it is cheaper for a company to buy a few satellites versus having to build thousands, and thousands of cell phone towers. The example I mentioned above, Thuraya, covers Europe to India and has had a lot of success. Do you remember the video-phone reports from the Iraq War? They were all done using Thuraya phone links.

That's the beauty of satellite phone service. You can be in the middle of nowhere and still get service. But it's unlikely to catch on in the US since we already get cell phone service nearly everywhere.

Hope this helps. Feel free to private message me if you have any further questions about satellites.

EDIT: Here's a link to one of the new phones:

http://www.thuraya.com/content/thuraya-smartphone.html

It looks just like a regular cell phone, except that it's fully compatible with ground cell phone networks AND the Thuraya satellite. Satellite roaming charges are a little expensive (50 cents a minute and up), but then again I've seen my cell phone company charge me more just because I called from outside the network!

Answer 6

Sattelite phones have been available for quite a long time, and never lose reception, regardless of location. They are extremely expensive. The cheap version, last time I checked, runs $1000 and up, plus service. Sattelite TV and Broadband is cheaper because it is typically stationary, or at leas constantly facing the correct bearing and azimuth to catch a signal. The true new way of the future is directional light wave communication, as light waves have an unlimited bandwidth, so everyone can have their own without the cost of cellular bandwidth conservation.

Answer 7

Actually, there are satellite phones. They are expensive. There has been talk over the years of building a Low orbit satellite system for cellular type phone use but it would be very expensive. There are not enough satellites at present to handle the call volume that would be expected if all cell carriers would switch to a satellite based system for personal cell phones.

Answer 8

It all comes down on cost. To use satellites for cell phone, it will requires quite a few of them to cover the planet. These satellites will also need to be replaced on a regular interval since they are orbiting at a lower altitude. Hence a continue investment cost. Typical lifspan of these satellites would be around 7 to 10 years.

Answer 9

The problem is in the power needed to transmit and receive over those distances. Not only would your cell phone need an 12 to 18 inch dish to receive the signal, you'd need a POWERFUL transmitter so that the signal FROM you phone could reach the satellite.

Answer 10

Because then they would be satellite phones, just like all of the other satellite phones we have now. Check out the price of satellite service, & you'll be glad you have cellular available to you.