I have multiple doubts based on this previous year gate question on computer network.
GATE2006-IT-67
Doubt 1 : How does this 100Mbps wire is multiplexed , Is it TDM(time division multiplex) or FDM(Frequency division multiplexed) . It matters because If it is TDM 10 stations can not use it at same time. If It is FDM 10 stations can use it at same time.
Doubt 2 : In solution to answer of part a, It is mentioned that with just 10 stations we can use it's full capacity(I am assuming FDM here). I think it is not possible. As each stations is transmitting only in 1 slot out of 3 slot. Lets say all 10 stations used it at first slot. then no station will be using wire for next two slots(IDEAL) , also it is nowhere mentioned that packets will be wire for next two slots(i.e. we can assume propagation time is negligible)
Doubt 3 : for part 3 , I have following understanding , Can someone please verify it ? (here also I am assuming FDM). This calculation is based on worst case. If there are 30 stations with each one having probability of transmitting in on of three slot is 1/3 then approximately 10 stations will be transmitting in each slot.(This will be observed over long period) hence for each slot there will be 10 stations. hence 30 is correct answer
