Satellite Communications

- Four Steps of Satellite Communications

Satellite communications consists of four steps:

• Uplink earth station or other ground equipment transmits the desired signal to the satellite
• The satellite amplifies the incoming signal and changes the frequency
• Satellites beam signals back to Earth
• Ground equipment receives signals

- Three Categories of Commercial Satellite Communication Service

Commercial satellite communication services fall into three broad categories: 

• Fixed Satellite Service (FSS), which uses ground equipment at fixed locations to receive and transmit satellite signals. FSS satellites support most of our domestic and international services, from international Internet connections to private business networks.
• Mobile Satellite Service (MSS), which uses a variety of mobile receiver and transmitter equipment to provide communications services to land mobile, maritime and airborne customers
• Broadcast Satellite Service (BSS), which uses very small ground equipment to provide high transmission power for reception. BSS is known for direct-to-consumer television and broadband applications such as DIRECTV.

- The Advantages and Disadvantages of Satellite Communication

Satellite communication technology is often used in natural disasters and emergencies when terrestrial communication services are disrupted. Mobile satellite equipment can be deployed to disaster areas to provide emergency communication services. 

A major technical disadvantage of satellites, especially those in geostationary orbit, is the delay inherent in transmission. While there are ways to compensate for this delay, it makes some applications that require real-time transmission and feedback, such as voice communications, less than ideal for satellites. 

Satellites face competition from other media such as fiber optics, cables and other land-based transmission systems such as microwaves and even power lines. The main advantage of satellites is that they can distribute signals from one point to multiple locations. Therefore, satellite technology is ideal for "point-to-multipoint" communications such as broadcasting. SATCOM does not require a large investment on the ground - making it ideal for dispersed populations, underserved and remote areas. 

Satellite and other transmission mechanisms such as fiber optics, cable and other terrestrial networks are not mutually exclusive. A combination of delivery mechanisms may be required, which has given rise to various hybrid solutions in which satellite can be a link in a chain combined with other media. Terrestrial service providers called "transmitters" have the ability to receive and transmit signals from satellites and provide connections to other terrestrial networks.

- The Future of Satellite Communications

In a relatively short period of time, satellite technology has grown from experimental (Sputnik 1957) to mature and powerful technology. Megaconstellations of thousands of satellites are being developed to bring internet access to anywhere on Earth. Future communications satellites will have more onboard processing power, more power, and larger antenna apertures, which will allow satellites to handle more bandwidth. Further improvements in satellite propulsion and power systems will increase their service life from the current 10-15 years to 20-30 years. 

In addition, other technological innovations such as low-cost reusable launch vehicles are also being developed. Emerging applications will drive demand for satellite services in the coming years as more video, voice and data traffic demands greater bandwidth. The need for more bandwidth, coupled with continued innovation and development in satellite technology, will ensure the long-term viability of the commercial satellite industry in the 21st century.

[More to come ...]