# Recent questions tagged slotted_aloha

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16. In a CDMA/CD network with a data rate of 10 Mbps, the maximum distance between any station pair is found to be 2500 m for the correct operation of the collision detection process. What should be the maximum distance if we increase the data rate to 100 Mbps? To 1 Gbps? To 10 Gbps?
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15. In a CDMA/CD network with a data rate of 10 Mbps, the minimum frame size is found to be 512 bits for the correct operation of the collision detection process. What should be the minimum frame size if we increase the data rate to 100 Mbps? To 1 Gbps? To 10 Gbps?
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11. We have a pure ALOHA network with 100 stations. If $T_{fr} = 1 \mu s$, what is the number of frames each station can send to achieve the maximum efficiency. 12. Repeat Exercise 11 for slotted ALOHA.
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In an infinite-population slotted ALOHA system, the mean number of slots a station waits between a collision and a retransmission is 4. Plot the delay versus throughput curve for this system.
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A large population of ALOHA users manages to generate 50 requests/sec, including both originals and retransmissions. Time is slotted in units of 40 msec. (a) What is the chance of success on the first attempt? (b) What is the probability of exactly k collisions and then a success? (c) What is the expected number of transmission attempts needed?
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Consider the delay of pure ALOHA versus slotted ALOHA at low load. Which one is less? Explain your answer.
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Shall I cover token passing and aloha in flow control methods in computer network. Please suggest as I don't want to waste time if it's not in syllabus. Thanks
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The bandwidth of a given medium for transferring the data is 100 Mbps. The user starts with pure aloha for transmission after half of the data is transferred user switched to slotted aloha. Then how much throughput will be gain or loss by the user in the second half? A 50% loss B 100% loss 100% gain D 200% gain i am getting 100% tell me what u are getting
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Consider 2 stations at a distance of 1 km from each other. A station transmits frames of length 100 bits at the rate of 1 Mbps. Velocity of propagation is 2 * 108 m/s. Assume that each station generates frames at an average rate of 10000 frames per second. What is the probability of collision for pure ALOHA and slotted ALOHA ?
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Let N station share 60 kbps of slotted aloha channel. Frame size is 1024 bits which are send at every 40 seconds. The value of N is ?
1 vote
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A slotted ALOHA network transmits 200-bit frames using a shared channel with a 200 Kbps bandwidth. Find the throughput of the system (all stations put together) produces 250 frames per second: 49 368 149 151
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A large population of ALOHA users manages to generate $50 \hspace{0.1cm} requests/sec$, including both originals and retransmissions. Time is slotted in units of $40 \hspace{0.1cm} msec$. What is the chance of success on the first attempt? What is the probability of exactly k collisions and then a success? What is the expected number of transmission attempts needed?
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In an infinite slotted ALOHA system the mean number of slots a station waits between a collision and a retransmission is 4. Give the relationship between the delay versus throughput of this system.
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6000 stations are competing for use of single slotted aloha channel. The average station makes 30 requests/hr ,where each request is for 500 us(micro sec) duration. calculate normalized total traffic on channel
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measurements of a slotted aloha channel shows that 20% of slots are idle. 1.what is normalized total traffic in channel? 2.what is normalized throughput?
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I have a lot of problems to solve numericals of Aloha. In Test series they are asking such questions which i'm unable to understand. Is there any good material for it? Please provide it or explain some concepts.
1 vote
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A group of N stations share 100 Kbps slotted ALOHA channel. Each station output, a 500 bits frame on an average of 5000 ms; even if previous one has not been sent. What is the required value of N?
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Suppose there are 4 nodes N1, N2, N3 and N4 are using a slotted ALOHA channel to send their own huge data. When competing all the nodes to transfer their data only one node will get succeeded with a probability P. The time is divided into slots S1, S2, S3 ….and so on. What is probability of N1 succeeded in slot 5? 4*(1-P)3(P(1-P)3) P(1-P)3(1-P(1-P)3) 4*P(1-P)3(1-P(1-P)3) 4*P(1-P)3(1-P3(1-P)3)
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In a aloha implemented shared channel probability of transmission of a station in a time span of T is p. Given, probability such that NO station transmit in a time duration of $2T$ is $50\%$ , where T = one frame transmission time. What is the value of p is if total no of station = $100$
1 vote
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Consider a system generating 20 bit frames and connected through a shared 20kbps channel. Find throughput in percent if slotted ALOHA is used and frame rate is 1000 fps.
You have two computers, $A$ and $B$, sharing a wireless network in your room. The network runs the slotted Aloha protocol with equal-sized packets. You want $B$ to get twice the throughout over the wireless network as $A$ whenever both nodes are backlogged. You configure $A$ to send packets with ... of $B$ to, in order to achieve your throughout goal? $p/(1+p)$ $p/(1+2p)$ $2p/(1+p)$ $1/2$