RECENT TRENDS IN SATELLITE COMMUNICATION

ByS.SURIYA PRAKASH 2011DEC086

G.VISHAL 2011DEC095

A satellite is an object that orbits another

object . The term is often used to describe an artificial satellite.

A communications satellite is an artificial satellite stationed in space for the purposes of telecommunications using radio at microwave frequencies.

SATELLITE COMMUNICATION

In 1962, the American telecommunications

giant AT&T launched the world's first true communications satellite, called Telstar.

Then, countless communications satellites have been placed into earth orbit, and the technology being applied to them is forever growing in sophistication

INTRODUCTION

FREQUENCY BAND

Band Download Bands MHz

Uplink Bands MHz

UHF (Military) 250-270 292-312

C Band (Commercial)

3700-4200 5925-6425

Ku Band (Commercial)

11700-21200 14000-14500

Ka Band (Commercial)

17,700-21200 27500-30,000

Ka Band (Military) 20200-21200 43500-45500

GEO: The most common type of communications satellites,

particularly the broadcast satellites like AfriStar, Intelsat, PanAmSat, Eutelsat and ASTRA etc., are in geosynchronous orbit.

MEO: A medium Earth orbit (MEO) satellite is one with an orbit from a few 100 miles to a few 1000 miles above the Earth's surface.

LEO: A low Earth orbit (LEO) satellite system consists of a large number of satellites each in a circular orbit at a constant altitude between 320 and 800 km.

ORBITAL PATERN

Military satellite communications (or milsatcom)

systems are typically categorized as wideband, protected, or narrowband.

SATELLITE COMMUNICATION IN MILITARY

The Wideband Gap filler Satellite program will produce

generation of wideband communications for the Defense (DOD).

WIDE BAND GAPFILLER SATELLITE

Defense Systems Agency and Joint Staff indicate

that a global wideband satellite communications can excess of 15 megabits per second will be needed by the middle of the next decade.

The Advanced Wideband System will take advantage of the commercial and government technology advances of the first half of this decade to meet expected needs. Laser crosslinks, space- based data processing and routing systems, and highly agile multibeam/phased- array antennas will most likely be included

ADVANCED WIDE BAND SYSTEM

Protected systems have the ability to avoid, prevent,

negate, or mitigate the degradation, dis unauthorized access, or exploitation of communications services by adversaries or the environment protected systems include the Advanced Extremely High Frequency System and Advanced.

PROTECTED COMMUNICATION

In the past, the term "narrowband" implied data rates of

less than 64 kilobits per second, but boundary could apply in the future as higher data rates to small terminals become possible.

NARROW BAND COMMUNICTION

In early fiscal year 2002, DOD initiated a

Transformational Communications Study to accelerates delivery of advanced capabilities with state-of-the art technology to the field.

ACCELERATING CAPABILITY

Amateur radio

- Access to OSCAR satellite. - Low earth orbits.

Internet - High Speed. - Useful for far away places.

Military - Uses geostationary satellites. - Example: The Defense Satellite Communications System (DSCS).

APPLICATIONS

Future satellite communications cannot

prescind from the evolution of terrestrial broadcast and broadband communication systems.

By using this the communication in military will be improved

CONCLUTION