1. Radio Antennas work best when the diameter of the antenna is equal to the wave length of the radio wave. Reasonable antennas range from 1 cm to 5 meters in diameter. What frequency range does this cover?
2. Ten signals, each requiring 4000 Hz (conventional telephone lines), are multiplexed onto a single channel using FDM. What is the minimum bandwidth required for the multiplexed channel? Assume that the guard bands are 400 Hz wide.
3. Why is the PCM sampling time been set at 125 microseconds? Fully support your answer.
4. How long will it take to transmit a 1 Gigabyte file from one VSAT to another using a hub as shown in Figure 2-17 of Tanenbaum's book? Assume that the uplink is 1 Mbps, the downlink is 7 Mbps, and circuit switching is used with 1.2 seconds circuit setup time.
5. Calculate the transmit time in the previous question if packet switching is used instead. Assume that the packet size is 64 Kilobytes, the total switching delay in the satellite and hub is 10 microseconds per packet and the packet header size is 32 bytes.