Describe the advantage of a parabolic reflective antenna.

CS547 Wireless Networking and Security Homework 02

Question 1: Simplify the following expression:

sin(2𝜋𝜋𝜋𝜋𝜋𝜋) + sin(2𝜋𝜋𝜋𝜋𝜋𝜋 − 𝜋𝜋) Question 2: Calculate the period of the following:

a) the function 𝜋𝜋(𝜋𝜋) = (10. cos 𝜋𝜋)2 b) the frequency of a telephone line which is 3 kHz

Question 3: A communication channel is designed to have a capacity of 300 Mbps with a bandwidth of 3 MHz. Calculate the Signal-to-Noise ratio that is required to achieve this data rate. Question 4: Given the following parameters for a switching network: N = number of hops between two end-point stations L = message length in bits B = data rate in bits per second (bps) P = fixed packet size in bits H = header size for each packet in bits S = call setup time (for circuit switching) in seconds D = propagation delay per hop in seconds For N=4, L=3200, B=9600, P=1024, H=16, S=0.2, D=0.001, compute the end-to-end delay for circuit switching and datagram packet switching. Assume that there are no acknowledgements and that the processing delay at each node is negligible. Question 5: Differentiate between a virtual channel and a virtual path. Question 6: IP and UDP all discard a packet that arrives with a checksum error and do not attempt to notify the source. Why? Question 7: Describe the advantage of a parabolic reflective antenna.

Question 8: Suppose a transmitter produces 50 W of power.

c) Express the transmit power in units of dBm and dBW d) If the transmitter’s power is applied to a unity gain antenna with a 900 MHz carrier

frequency, what is the received power in dBm at a free space distance of 100 m? e) Repeat (b) for a distance of 10 km. f) Repeat (c) but assume a receiver antenna gain of 2.