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Today we on planet earth are enjoying communicating through high-tech devices all around us while the satellites high above the planet are making this instantaneous communication possible. The era of satellite communication started almost 51 years ago with one giant space balloon. Echo 1 was the name given to the world's first communications satellite capable of relaying signals to other points on Earth, flying 1000 miles above the planet. Echo 1 was launched on August 12, 1960 by NASA. It was a giant metallic balloon 100 feet (30 meters) across laying the foundation of today's satellite communications.
The idea behind a communications satellite is simple: Send data up into space and beam it back down to another spot on the globe. Just like the moon the only natural satellite, communications satellites travel around a great circle (orbit) around planet earth. Most of these satellites travel at the same speed as of Earth. Base stations (Earth Stations) on the ground send signals to these satellites. There are three altitude classifications for satellite orbits; LEO – Low Earth Orbit ranging from 60-2000km above the earth, taking approximately 1.5 hrs for a full orbit, covering only a portion of the earth’s surface and having a lower latency; MEO – Medium Earth Orbit located above LEO and below GEO satellites, traveling in an elliptical orbit over the North and South Pole traditionally used for GPS navigation systems; GEO – Geostationary Orbit floating 35,786 kilometer above the equator with the same direction and speed as of the earth making it appear to the earth station as fixed in the sky. The majority of commercial communications satellites operate in this orbit; however, due to the distance from the earth they hold a longer latency.
Communication Satellites operate in four radio frequency bands titled as C band (uplink 5.925-6.425 GHz; downlink 3.7-4.2 GHz), X band (uplink 7.9- 8.4 GHz, downlink 7.25 – 7.75 GHz), Ku band (uplink 14 GHz; downlink 10.9-12.75 GHz) and Ka band (uplink 26.5-40GHz; downlink 18-20 GHZ). The C band is primarily used for voice and data communications as well as backhauling, X band is generally used for military communications and Wideband Global SATCOM (WGS) Systems, Ku band is used for consumer direct-to-home access, distance learning applications, retail and wholesale connectivity and the Ka band is primarily used for two-way broadband and military networks.
A typical satellite network typically consists of an earth station (communicating with the satellite), commonly referred to as a teleport, with hub equipment at one end and a Very Small Aperture Terminal (VSAT) antenna at the other end. The network equipment can be divided into two sets of equipment connected with each other: the Outdoor Unit (ODU) and the Indoor Unit (IDU). The network may follow Star, Mesh, Hybrid or Point-to-Point topology.
Satellite communication provides an ideal scenario for businesses and public organizations that are unable to access other communications services over remote or rural locations. Today, satellite communication can deliver a terrestrial-grade experience with voice, video, and data that can be accessed anywhere in the world. Ubiquitous coverage can be obtained with a global network of multiple satellites all tying into one central network management system.
The value chain of Satellite communication consists of:
Equipment Vendors - generally distinguished between pure antenna manufacturers and satellite equipment manufacturers that fabricate indoor or outdoor ground equipment, software and network management systems
Satellite Operators - responsible for the planning and cost of the construction and launch of satellite into space. They own and manage a fleet of satellites and decide coverage and geographic areas. They lease this bandwidth to service providers, government entities, television broadcasters, enterprises and sometimes direct to the end consumer.
Service Providers/ Network Operators - telecommunication operators or specialized telecommunication service providers who sell a full service package to the end customer. They lease capacity from satellite operators, purchase and operate the network equipment and are responsible for maintenance of the network.
Customers – Businesses, enterprises, large corporate and Government organizations who use satellite communication services.
Applications - Variety of applications related with broadcasting, networking and multi-casting data for enterprise networks including: Internet, E-mail, Video Streaming, VoIP etc.
In many regions and countries around the globe, the use of satellite communication systems to provide mobile telephony and high speed data broadband services has increased in recent years. Broadband delivery through satellites in various geographical regions is increasingly taking into consideration to bridge the digital divide. It is estimated that global satellite broadband users will increase from 1.5 million in 2011 to about 6 million by 2020. Some of the major global IP broadband service providers include Intelsat Network (operates a fleet of 52 communications satellites), Inmarsat (operates a fleet of 11communication satellites) and SES S.A (operates a fleet of 47 communication satellites). International experts are of the view that access to an always-on broadband service can be delivered through satellites for approximately the same price as terrestrial alternatives, however the service quality will likely remain inferior to the highest throughput terrestrial technologies.
Satellite communication is very important and advantageous in today's world, wherein this service is highly used during the times of natural disasters, people staying in remote areas and also for the military and defense purposes. Any other mode of communication failure can be rectified by using the satellite communication services which can be used anywhere, anytime and without any hindrances. Also, the long distance calls, usage of internet, etc are the other some of the advantages of satellite communication services.
With the demand for network capacity growing every passing day, satellites once again offer the potential to bridge the earth-bound limitations and provide greater bandwidth. A global vision supported with regulatory liberalization will be required to endorse the further growth of this communication channel – In an era of radio frequency spectrum usage. As more countries will gain access to satellite launch capabilities and orbital locations, enabling a vibrant and competitive Satellite market will be the key focus of our institutions and organizations.