4. a) Why does slotted Aloha perform better than Pure Aloha? Explain with an example. [10] b) The figure below shows the operation of slotted Aloha for a given time-period. Calculate the efficiency of the protocol. [10] node 1 node 2 2 node 3 1 1 3 + S C + 2 2 1 2 3 3 3 3 + CCES CEC C: collision E: Empty S: Successful 5. a) Why does CSMA/CD outperform Aloha? time [5] b) What will be the maximum and minimum backoff time-period in bit times after the 5th collision? [5]
Added by Pilar G.
Close
Step 1
This helps in reducing the chances of collisions compared to Pure Aloha where nodes can transmit at any time. Show more…
Show all steps
Your feedback will help us improve your experience
Akash M and 54 other AP CS educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Two nodes "A" and "B" that are attached at the opposite ends of 1000 m Ethernet cable. They both have a 1000-bit frame to send to each other. Both nodes attempt to transmit at t = 0. Assume the transmission rate is 10 Mbps and that CSMA/CD is used. After the first collision, node "A" will retransmit immediately after it senses the medium is idle. Station "B" will retransmit 50 microseconds after it senses the medium is idle. Assume that the speed of propagation is 2x10^8 m/sec. Assume no jamming signal is used. Collision occur at t = ____ sec. Station A will retransmit at t = ____ sec. The time it will take the frame from "A" to be completely delivered to "B" is ____ sec. The throughput of node A is ____ bps.
Akash M.
Suppose you have a 4 nodes A,B,C and D, contending for a channel using slotted ALOHA. Each node transmits with probability 40% and has an infinite number of packets to transmit. The slots are numbered starting at 1. All Answers should have 2 digits of precision. A. The probability node A's first successful transmission occurs in slot 1 is (probability is a number between 0 and 1): _____________ B. The probability that both node A is successful in slot 1 and B is successful in slot 2 is: _____________ C. The probability of no packet going through in slot 2, either because of no transmission or a collision is: _____________ D. The long run efficiency (as the number of packets goes to infinity) of the channel is: (a number between 0 and 100): _____________
Madhur L.
Recommended Textbooks
Computer Science and Information Technology
Introduction to Programming Using Python
Computer Science - An Overview
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD