1.

Solve : number of links not affecting transmission time in a circuit-switched network ??

Answer»

Quote

Suppose that all links in the network use TDM with 24 slots and
have a BIT rate of 1.536 Mbps. Also suppose that it takes 500 msec to establish an
end-to-end circuit before Host A can begin to transmit the file. How long does it take
to send the file? Each circuit has a transmission rate of ( 1.536 Mbps)/24 = 64 kbps,
so it takes (640,000 BITS)/(64 kbps) = 10 seconds to transmit the file. To this 10 seconds we add the circuit establishment TIME, giving 10.5 seconds to send the file.
Note that the transmission time is independent of the number of links: The transmission time WOULD be 10 seconds if the end-to-end circuit passed through one link or a hundred links.

Why does the number of links not affect the transmission time ?

Thanks.

I think you mean TDMA. Right?
Quote
TDM with 24 slots
Is this hoe work?
Quote
..through one link or a hundred links.
Who said that? It was 24 slots, now how did it get to hundreds of links?
Either it has 24 slots or is is not.
Read over the definition of TDM.
Simple TDM is not a dynamic system.
But if is, it is not.

Better systems use a more complex protocol. But if you don't need it, you don't do it. The idea is to deliver just what is needed, not more.

Piratical example. Some 48 people decide that maybe they want to have 24 conversations. Possibly all at the same time. But now always. So they invest in a communication system that can PROVIDE 24 voice channels using TDMA. The quality is good voice quality. They have no intention of sending video or any pictures ever. Just conversation when they want. They do not want to share their system with anybody. Never. So they install simple TDMA. They get what they pay for. Up to 24 conversations whenever they want. The system is private. Nobody else is on it. They like simple plain TDMA. Nothing else.


Discussion

No Comment Found

Related InterviewSolutions