CS 421A: FOUNDATIONS OF DATA NETWORKS HOMEWORK #2 (2 X 13-26 marks) 1. Given the frequencies listed below. Calculate the corresponding periods. 2. What is the bandwidth of a signal that can be decomposed into five sine waves with 3. What is the bit rate of the following signals? a. 24 Hz b. 8 MHz c. 140 KHz frequencies at 0, 20, 50, 100 and 200 Hz? All peak amplitudes are the same. Draw the bandwidth. A signal in which 1 bit lasts 0.001s a. b. c. A signal in which 1 bit lasts 2 ms A signal in which 10 bits lasts 20 pus. 4. A device sending out data at the rate of 1000 bps How long does it take to send out 10 bits? a. b. How long does it take to send out a single character (8 bits)? 5. A signal travels from point A to point B. at point a, the signal power is 100 W. at point B, 6. The attenuation of a signal of -10dB. What is the final signal power if it was originally 7. If the bandwidth of the channel is 5 Kbps, how long does it take to send a frame of 8. We measure the performance of a telephone line (4 KHz in bandwidth). When the signal c. How long does it take to send a file of 100,000 characters the signal power is 90 W. what is the attenuation in decibels? 5W 100,000 bits out of this device? is 10 V the noise is 5 mV. What is the maximum data rate supported by this telephone line. 9. A line has signal-to-noise ratio of 1000 and a bandwidth of 4000 KHz. What is the 10. A signal with 200 milliwatts power passes through 10 devices, each with an average 11. We need to upgrade the channel to a higher bandwidth. Answer the following questions. maximum data rate supported by this line? noise of 2 microwatts. What is the SNR? What is the SNRaB? How is the rate improved if we double the bandwidth? a. b. How is the rate improved if we double the SNR? 1 million bytes and bandwidth of the channel is 200 Kbps? channel bandwidth is 12. What is the transmission time of the packet sent by a station if the length of the packet is 13. What is the length of a bit in a channel with propagation speed of 2 x 10m/s of the a. 1 Mbps? b. 10 Mbps? c. 100 Mbps