[Solved]Q3 Wireless Sensor Network Link Protocol Frame Retransmitted Whenever Receives Error Avera Q37127646
Q3. (a) In a wireless sensor network link protocol, a frame is retransmitted whenever it receives an error. The average number of frames transmitted per error-free reception (Nr) is (I FER), where FER is the frame error rate. If the overhead per frame is n bits, which is independent of the frame size (N bits), show that the average number of bits transmitted per error- free reception of one bit of information is given by: N+n 7 marks] where Pe is the bit error probability of the link. (b) Stations are allowed to transmit onto a shared radio channel whenever they like (i.e. pure Aloha is in operation). The transmission rate is 4Mbps and each station transmits fixed sized packets of 1000 bits each. If 800 packets are transmitted in one second, and follow a Poisson distribution, calculate the normalised offered load to the network (G) and from this the probability of a collision on the radio channel. [5 marks] (c) Two base stations are 40Km apart and 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 8OMbps. Assuming the link has a bit error rate of 4 x 105, and a velocity of propagation v -3 x 10% m/s, determine the link utilisation efficiency using the following protocols: (i) Idle RQ (ii) Continuous RQ with a send window buffer k-2; (ii) Continuous RQ with a send window buffer k-200; (iv) Suggest a way to increase the link utilisation of Selective repeat RQ [6 Marks] 3 Marks] [2 Marks] [4 Marks] scheme. Discuss potential disadvantages of such approach. Show transcribed image text Q3. (a) In a wireless sensor network link protocol, a frame is retransmitted whenever it receives an error. The average number of frames transmitted per error-free reception (Nr) is (I FER), where FER is the frame error rate. If the overhead per frame is n bits, which is independent of the frame size (N bits), show that the average number of bits transmitted per error- free reception of one bit of information is given by: N+n 7 marks] where Pe is the bit error probability of the link. (b) Stations are allowed to transmit onto a shared radio channel whenever they like (i.e. pure Aloha is in operation). The transmission rate is 4Mbps and each station transmits fixed sized packets of 1000 bits each. If 800 packets are transmitted in one second, and follow a Poisson distribution, calculate the normalised offered load to the network (G) and from this the probability of a collision on the radio channel. [5 marks] (c) Two base stations are 40Km apart and 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 8OMbps. Assuming the link has a bit error rate of 4 x 105, and a velocity of propagation v -3 x 10% m/s, determine the link utilisation efficiency using the following protocols: (i) Idle RQ (ii) Continuous RQ with a send window buffer k-2; (ii) Continuous RQ with a send window buffer k-200; (iv) Suggest a way to increase the link utilisation of Selective repeat RQ [6 Marks] 3 Marks] [2 Marks] [4 Marks] scheme. Discuss potential disadvantages of such approach.
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Answer to Q3. (a) In a wireless sensor network link protocol, a frame is retransmitted whenever it receives an error. The average … . . .
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