6.3-1. Multiple Access protocols (a). Consider the figure below, which shows the arrival of 6messages for transmission at different multiple access wireless nodes at times t = 0.3, 1.7, 1.8, 2.5,4.2, 4.6. Each transmission requires exactly one time unit.t=0.0OO1U2304LOt=1.0For the pure ALOHA protocol, indicate which packets are successfully transmitted. You can assumethat if a packet experiences a collision, a node will not attempt a retransmission of that packet untilsometime after t=5.623t=2.04t=3.05t=4.06t=5.0

Pure ALOHA can be defined in such a way that it is a easy and unslotted random entry to protocol…

6.3-1. Multiple Access protocols (a). Consider the figure below, which shows the arrival of 6 messages for transmission at different multiple access wireless nodes at times t = 0.3, 1.7, 1.8, 2.5, 4.2, 4.6. Each transmission requires exactly one time unit. t=0.0 O O O 1 N t=1.0 4 23 t=2.0 4 For the pure ALOHA protocol, indicate which packets are successfully transmitted. You can assume that if a packet experiences a collision, a node will not attempt a retransmission of that packet until sometime after t=5. t=3.0 5 t=4.0 6 t=5.0

6.3-1. Multiple Access protocols (a). Consider the figure below, which shows the arrival of 6 messages for transmission at different multiple access wireless nodes at times t = 0.3, 1.7, 1.8, 2.5, 4.2, 4.6. Each transmission requires exactly one time unit. t=0.0 O O O 1 N t=1.0 4 23 t=2.0 4 For the pure ALOHA protocol, indicate which packets are successfully transmitted. You can assume that if a packet experiences a collision, a node will not attempt a retransmission of that packet until sometime after t=5. t=3.0 5 t=4.0 6 t=5.0

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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. Consider a packet of length L that begins at end system A and travels over three links to a destination end system. These three links are connected by two packet switches. Let di, si, and Ridenote the length, propagation speed, and the transmission rate of link i, for i=1,2,3. The packet switch delays each packet by dproc. Assuming no queuing delays, in terms of di, si, Ri, (i=1,2,3), and L, what is the total end-to-end delay for the packet? Suppose now the packet is 1,500 bytes, the propagation speed on all three links is 2.5-108m/s, the transmission rates of all three links are 2 Mbps, the packet switch processing delay is 3 msec, the length of the first link is 5,000 km, the length of the second link is 4,000 km, and the length of the last link is 1,000 km. For these values, what is the end-to-end delay?
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6.3A-1. Multiple Access protocols (1). Consider the figure below, which shows the arrival of 6 messages for transmission at different multiple access wireless nodes at times t=0.1, 1.4, 1.8, 3.2, 3.3, 4.1. Each transmission requires exactly one time unit. t=0.0 O o 1 O o 1 2 3 For the pure ALOHA protocol, indicate which packets are successfully transmitted. You can assume that if a packet experiences a collision, a node will not attempt a retransmission of that packet until sometime after t=5. 4 5 t=1.0 9 2 t=2.0 45 t=3.0 6 t=4.0 t=5.0
Suppose A is connected to B via an intermediate router R, as in the previous problem. The A-R link is instantaneous, but the R–B link transmits only one packet each second, one at a time (so two packets take 2 seconds). Assume A sends to B using the sliding window protocol with SWS = 4. For Time = 0, 1, 2, 3, 4, state what packets arrive at and are sent from A and B. How large does the queue at R grow?
6.3-2. Multiple Access protocols (b). Consider the figure below, which shows the arrival of 6 messages for transmission at different multiple access wireless nodes at times t = 0.3, 1.7, 1.8, 2.5, 4.2, 4.6. Each transmission requires exactly one time unit. t=0.0 U 3 U चं n 50 U t=1.0 60 23 t=2.0 For the slotted ALOHA protocol, indicate which packets are successfully transmitted. You can assume that if a packet experiences a collision, a node will not attempt a retransmission of that packet until sometime after t=5. t=3.0 5 t=4.0 6 t=5.0
Suppose two hosts (Host-A and Host-B) are connected through a shared Ethernet bus of 1 Mbps. The distance between two nodes is 5 meters. The signal propagation speed over physical media is 2.5 x 10^5 meters/second. Compute the propagation delay in this case. What will be the propagation delay for a shared bus of 10 Mbps instead Suppose both hosts sense idle channel at the same time and starts transmission. Will it result in collision (yes or no) If yes: How much time is needed to detect this collision at Host-A? If yes: How much time is needed to detect this collision at Host-B?
6.3B-5. Multiple Access protocols (5). Consider the figure below, which shows the arrival of 6 messages for transmission at different multiple access wireless nodes at times t=0.1, 0.8, 1.35, 2.6, 3.9, 4.2. Each transmission requires exactly one time unit. t=0.0 n [ 2 3 t=1.0 4 t=2.0 4 For the CSMA/CD protocol (with collision detection), indicate which packets are successfully transmitted. You should assume that it takes .2 time units for a signal to propagate from one node to each of the other nodes. You can assume that if a packet experiences a collision or senses the channel busy and that that node will not attempt a retransmission of that packet until sometime after t=5. If a node senses a collision, it stops transmitting immediately (although it will still take .2 time units for the last transmitted bit to propagate to all other nodes). Hint: consider propagation times carefully here. Hint: consider propagation times carefully here. t=3.0 5 6 t=4.0 t=5.0