Friday, December 15, 2006

How Does Satellite Internet Access Work?
By : Angela Abbette 19 or more times read
Just as satellite dishes competed with cable decades ago for premium movie channel services, dishes are now back, offering satellite acces to the internet to compete with cable and DSL. In a practical sense, satellite Internet access isn't so much of a competing technology as much as it is an alternative in areas where cable or DSL services are not available. Internet access via satellite is a somewhat pricey option at this time, though with downstream rates from 150-1,200 Kbps and upstream rates around 50-150 Kbps, available bandwidth is far greater than dialup connectivity.

Satellite Internet access operates via geostationary (fixed-position) satellites that beam microwaves from about 22,300 miles above the Earth's equator to your dish antenna and transceiver (transmitter/receiver). Satellite Internet access is available in two forms: two-way and one-way.

A typical two-way satellite Internet connection allows for upstream and downstream transmissions via satellite. Here is an example of a typical two-way satellite data transmission:

1. Your transceiver (connected to your computer) passes the digital signal to your dish antenna, which beams the information to the satellite (transponder).

2. The transponder forwards/beams the digital signal to a network operations center (NOC) back on the ground.

3. The NOC forwards the data request on to the Internet via land-based infrastructure.

4. Data returning from the Internet follows the same process (in reverse) back to your computer.

In theory, this entire process takes only about half of a second, but in practice it takes longer, so this isn't the method of choice for online gamers. (The time delays inherent in satellite communication can be somewhat distracting to online gainers.) A two-way setup provides always-on Internet connectivity that makes access convenient.

A one-way satellite transmission downstreams data from the transponder to your dish antenna but does not allow for transmitting data upstream in the same manner. One-way internet satellite access requires that you transmit upstream data through a dialup connection but only downstream data travels via satellite.

It is worth noting that because satellite Internet access operates off "lineof-sight" communication, transmissions are susceptible to heavy precipitation signal degradation (rain fade) and occasional solar interference. A variation of this technology called fixed wireless uses cell towers and has less latency but even more line-of-sight problems. But with the growth of the internet, and need of customers, satellite internet service is improving both in practicality and price.

So if DSL or cable or even dial up internet service is not an option for you, satellite internet service may be your ticket to net freedom.