CHAPTER 3

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1. For a terrestrial radio link of 30 kilometers, assuming that speed of light is 3 × 10⁸ meters/second, the propagation delay is 30,000 / (3 * 10 ⁸) seconds = 100 microseconds.

2. When the cable length is 40 kilometers and the speed of transmission in the coaxial cable is 2.3 × 10⁸ meters/second, the propagation delay is 40,000/ (2.3 * 10⁸) seconds = 173.91 microseconds.

3. The propagation delay in an optical fiber of 100 kilometers if the speed is 2 × 10⁸ meters/second, is 100,000 / (2 × 10⁸) seconds = 0.5 msec.

4. In satellite communication, broadcasting and voice communication are done in the C band and Ku band.

   Band Designation	Frequency Range
   L band	1-2 GHz
   S band	2-4 GHz
   C band	4-8 GHz
   X-band	8-12 GHz
   Ku band	12-18 GHz
   K band	18-27 GHz
   Ka band	27-40 GHz
   Q band	33-50 GHz
   U band	40-60 GHz
   V band	40-75 GHz
   W band	75-110GHz

5. In mesh configuration, the communication is from one Earth station to another Earth station. Hence, the propagation delay is 240 msec. In star configuration, the transmission is from VSAT to the satellite, satellite to the hub, hub to the satellite, and then satellite to the other VSAT. Hence, the propagation delay is 480 msec.

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