1. Considering the analog signal with maximum frequency of 300kHz, what is the maximum quantization level where the maximum data rate is 7 Mbps? (5 points) 2. Considering the parallel transmission mode with 4 links, find the transmission time of this parallel mode to transmit 2 bytes of data where each link has transmission rate of IMbps. What is the transmission time if serial transmission mode with same link speed and data size is used? (5 points) 3. A company has a low pass 1MHz bandwidth communication line. The company needs 4 separate independent channels each capable of sending at least 2Mbps. QAM technology has been selected to implement. What is the minimum bits per baud for each channel? What is the number of points in the constellation diagram for each channel? Assume d=0. (5 points) 4. A cable company uses one of the cable TV channels (with a bandwidth of 4MHz) to provide digital communication for each resident. What is the available data rate for each resident if the company uses a 64- QAM technique? Assume d = 0. (5 points) 5. Find the bandwidth for the following situation if we need to modulate a 4-kHz voice. (3 points) (a) AM (b) FM (P = 4) (c) PM (B = 2) 6. Assume that a voice channel occupies a bandwidth of 4kHz. We need to multiplex 10 voice channels with guard bands of 400 Hz using FDM. What is the required bandwidth? (5 points) 7. A synchronous TDM combines 10 digital sources where each has data rate of 500-kbps. Each output slot carries 4 bits from each digital source, but one extra bit is added to each frame for synchronization. Find an output frame size in bits, output frame rate, and output data rate. (10 points) 8. Assume synchronous time division multiplexer with three inputs - channel 1, channel 2, and channel 3. The output of this multiplexer produces synchronous 18-bit frames that are provisioned for stuffing as shown in the figure. The stuffing process can occur with each frame. The output link of this multiplexer operates at 36 Mbps. The input channel data rates have an upper bound, lower bound, and average data rates at channel 1? (10 points) 5, 5, 5, CCC32121121131 Output from the s chool s36Mbp. Cuffing interface - data arhit ich 9. Find the random numbers generating by x'+x' + x + 1 using Viterbi algorithm. Is it primitive? (5 points) 10. Assume that the BER is 10. (a) What is the probability that the 1000-bit frame would be received without an error (5 points) (b) If Stop-and-wait flow control is used, what is the probability that the station transmits 4 same frames to receive a positive acknowledgement? Assuming no packet lost during these transmissions. (5 points) (Problem 11-12) Assume that the dataword, D, is 1001100110" and divisor pattern, P, is 11001". Answer the following questions. You should show your steps. 11. Using CRC, find the transmitting codewords using modulo-2 operation. (5 points) 12. Find the CRC redundant bits using shift registers. Draw the shift register first. (10 points) 13. Recall that HDLC flags of 01111110. What is the binary sequence on an HDLC link if the following frame is to be sent on the link? (5 points) "11111011111111110111101011111111011" 1. Considering the analog signal with maximum frequency of 300kHz, what is the maximum quantization level where the maximum data rate is 7 Mbps? (5 points) 2. Considering the parallel transmission mode with 4 links, find the transmission time of this parallel mode to transmit 2 bytes of data where each link has transmission rate of IMbps. What is the transmission time if serial transmission mode with same link speed and data size is used? (5 points) 3. A company has a low pass 1MHz bandwidth communication line. The company needs 4 separate independent channels each capable of sending at least 2Mbps. QAM technology has been selected to implement. What is the minimum bits per baud for each channel? What is the number of points in the constellation diagram for each channel? Assume d=0. (5 points) 4. A cable company uses one of the cable TV channels (with a bandwidth of 4MHz) to provide digital communication for each resident. What is the available data rate for each resident if the company uses a 64- QAM technique? Assume d = 0. (5 points) 5. Find the bandwidth for the following situation if we need to modulate a 4-kHz voice. (3 points) (a) AM (b) FM (P = 4) (c) PM (B = 2) 6. Assume that a voice channel occupies a bandwidth of 4kHz. We need to multiplex 10 voice channels with guard bands of 400 Hz using FDM. What is the required bandwidth? (5 points) 7. A synchronous TDM combines 10 digital sources where each has data rate of 500-kbps. Each output slot carries 4 bits from each digital source, but one extra bit is added to each frame for synchronization. Find an output frame size in bits, output frame rate, and output data rate. (10 points) 8. Assume synchronous time division multiplexer with three inputs - channel 1, channel 2, and channel 3. The output of this multiplexer produces synchronous 18-bit frames that are provisioned for stuffing as shown in the figure. The stuffing process can occur with each frame. The output link of this multiplexer operates at 36 Mbps. The input channel data rates have an upper bound, lower bound, and average data rates at channel 1? (10 points) 5, 5, 5, CCC32121121131 Output from the s chool s36Mbp. Cuffing interface - data arhit ich 9. Find the random numbers generating by x'+x' + x + 1 using Viterbi algorithm. Is it primitive? (5 points) 10. Assume that the BER is 10. (a) What is the probability that the 1000-bit frame would be received without an error (5 points) (b) If Stop-and-wait flow control is used, what is the probability that the station transmits 4 same frames to receive a positive acknowledgement? Assuming no packet lost during these transmissions. (5 points) (Problem 11-12) Assume that the dataword, D, is 1001100110" and divisor pattern, P, is 11001". Answer the following questions. You should show your steps. 11. Using CRC, find the transmitting codewords using modulo-2 operation. (5 points) 12. Find the CRC redundant bits using shift registers. Draw the shift register first. (10 points) 13. Recall that HDLC flags of 01111110. What is the binary sequence on an HDLC link if the following frame is to be sent on the link? (5 points) "11111011111111110111101011111111011
