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