Q2. (a) Two towns 20km apart are connected by a microwave data link. Data is sent across the link in 800 byte frames and
Posted: Sun May 15, 2022 8:21 am
Q2. (a) Two towns 20km apart are connected by a microwave data link. Data is sent across the link in 800 byte frames and the link operates at a data rate of 120Mbps. Assuming the link has a bit error rate of 4 x 10-5, and a velocity of propagation v = 3 x 108 m/s, determine the link utilisation efficiency using the following protocols: [6 Marks] [3 marks] a (i) Idle RQ (ii) Selective repeat RQ with a send window buffer k=2. (iii) Suggest a way to increase the link utilisation of the Selective repeat RQ scheme. Discuss potential disadvantages of such an approach. [6 Marks]