The Gateway to Computer Science Excellence
First time here? Checkout the FAQ!
x
0 votes
83 views
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 ?
asked in Computer Networks by Loyal (6.5k points) | 83 views
0
Is it 863?
0
is aloha in syllabus?
0
I think flow and access control are in syllabus.

3 Answers

+1 vote
Best answer

Given Bandwidth (B) = 60 Kbps = 60*103

Bitrate for each host (b) = 1024/40 = 25.6 b/s

 

In slotted ALOHA, Number of stations N = (0.368 * Bandwidth) / Bitrate of each station.

= (0.368 * 60*103) / 25.6

= 862.5 stations

 

answered by (183 points)
selected by
0
Can u explain how u got the formula ?
+2 votes

The maximum throughput for Slotted aloha is $36.8$%, $0.368$
Hence, effective bandwidth $= 0.368*60kbps=22.08 kbps$
Bits per second outputted by each station $= 1024/40 = 25.6 bps = 25bps$

N station outputs 25 bits on a channel which has the effective B.W of 23.16 kbps
So, 
   $  (22.08*10^3)/25 = 22080/25= 883.2$, So 883 stations
 

answered by Junior (517 points)
edited ago by
0
Maximum throughout is 0.368 not 0.386 so answer is wrong..
0
@Prabhu thanks, i corrected my solution.
+1 vote
throughput of slotted aloha=(efficiency of slotted aloha)*(bandwidth of the channel)........(1)

throughput of slotted aloha=(number of stations in slotted aloha)*(throughput of each stations)...(2)

so from 1 and 2

(number of stations in slotted aloha)*(throughput of each stations)=(efficiency of slotted aloha)*(bandwidth of the channel)

where the efficiency of slotted aloha is 36.8% or 0.368......
answered by (211 points)


Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true

41,063 questions
47,662 answers
147,329 comments
62,381 users