etter prepared than satellites operating at other bands to accommodate telemedicine, tele-education, telesurveillance, and networked interactive games. A disadvantage of Ka-band is that it's even higher in the frequency band than the other bands, SO rain fade (i.e., degradation of signal because of rain) can be a more severe issue. Thus, more intelligent technologies have to be embedded at the terminal points to cost-effectively deal with error detection and correction. L-Band L-band operates in the 390MHz to 1,550MHz range, supporting various mobile and fixed applications. Because L-band operates in the lower frequencies, L-band systems are more tolerant of adverse weather conditions than are other systems. It is largely used to support very-small-aperture terminal (VSAT) networks and mobile communications, including handheld terminals (such as PDAs), vehicular devices, and maritime applications. Shrinking Earth Stations We've progressed very quickly in satellite history. The first earth station that accompanied the Early Bird satellite in 1965 had a massive facility. The dome on the building was 18 stories high, the antenna weighed 380 tons, and the entire building had liquid helium running through it to keep it cool. This was not something an end user could wheel into a parking lot or place on top of a building. But we have continued to shrink the sizes of earth stations, and today many businesses use VSATs, in which the dish diameter is 2 feet (0.6 m) or less. You can literally hang a VSAT outside your window and have a network up and running within several hours (assuming that you have your frequency bands allo- cated and licensed). Satellite Network Segments Satellite networks have three major segments: Space segment-The space segment is the actual design of the satellite and the orbit in which it operates. Most satellites have one of two designs: a barrel-shaped satellite, normally used to accommodate standard communica- tions, or a satellite with a very wide wingspan, generally used for television. Chapte