Satellite Communication Overview of the Technologies & the Antenna System

Key Issues

Looking ahead of the 1990s, one could observe a very rapid expansion of the global market in satellite communication into personal communication and new mobile satellite services, such as Personal Conversation System (PCS) and Mobile Satellite Services (MSS) respectively, Low Earth Orbit (LEO) satellite systems, Global Positioning System (GPS) navigation, and new direct broadcast satellite services. LEO satellite services were introduced towards the end of the 1990s, and the growth depended on competitive factors. The conventional Fixed Satellite Services (FSS) and Maritime Mobile Satellite Services (MMSS) grew steadily but not as before.

Optical fiber cables, now forming a greater part of this conversation revolution throughout the world, severely challenged the fixed satellite services. Very high data rates, similar to High Dynamic Range (HDR) graphics, which require greater than 155Mb per second of data transfer, which required excellent signal conditioning, were being carried by the fiber optics cables.

Fiber optic cables have a better performance than satellites, having much less time delay in transmission. It was a time when satellite services needed to prove their advantage on HDR applications and networking, having more modest data rates, for example, T1=1.5Mb per second. A T-1 line consists of 24 individual channels, each of which supports up-to 64Kbits per second data rate.

The advantages include wide-area coverage, distance insensitivity, flexibility, multiple access and destination capabilities, and economy. Although much on the HDR traffic, such as multi-channel telephone trunks, from satellites to cables, will be transmitted through fiber optics cables, new opportunities opened up for HDR satellites to carry HDTV picture signal distribution, and also support the emerging field of Distributed High-Performance Computing (DHPC). To gain access to this application market, HDR satellites needed to be developed and deployed commercially.

Satellite Communication Systems

A brief discussion, relating to the assessment of satellite communication … Read the rest

Satellite Communication Components for Communication Satellites

The simple application of any communication satellite, no matter whether it is low earth orbital or geosynchronous, includes the transmission of facts from an originating Earth station towards the satellite concerned, which can be termed as “up-linking,” followed by re-transmission from the same info towards the designated Earth station. This re-transmission is termed “down-linking.” The downlink on the details may be to one particular unique Earth station or broadcasted over a chosen number of Earth stations, situated at a bigger region.

To perform this up-linking and down-linking, the satellite features a receiver and also a acquire antenna, a transmitter, and also a transmit antenna, just like a set of a walkie-talkie, which includes a receiver in addition to a transmitter with an antenna, even though is right here, the “receive” and “transmit” is carried out through the same antenna. Satellites will need antennas separately for their two functions of acquiring and transmit. On top of that, the satellite has electronic switches.

This can be utilized to logically switch the uplink signals, down-linking it towards the suitable Earth stations. It has an electronic black-box to ascertain the destination or destinations from the signals getting down-linked to the Earth Stations. There’s that ever vital electrical energy within a satellite necessary in maintaining alive the electronic circuitry. The exact component structure of a satellite may well differ from one towards the other, based on its actual application, but the standard element requirements remain the same.

The electrical power needed by satellites for receiving and transmitting signals tremendously depends upon its orbital path, that is, irrespective of whether it can be a low Earth or geosynchronous orbital satellite. Electrical power requirements mainly depend upon the height of the satellite above the Earth. The higher it can be, a satellite would want that considerable energy … Read the rest