The difference between multilevel tdm multislot tdm and pulse-stuffed tdm?

they are all techniques used to handle a disparity/inequality in the i/p lines data rates.

1-Multilevel TDM.

it's used when the i/p lines data rates are multiple of each other.

for example if u have two i/p lines with data rate of 100kbps each

and another (third) i/p line with data rate of 200kbps

we multiplex the 1st two together (100k + 100k) to produce a data rate of 200kbps

2-Multislot TDM.

it's used to give a single i/p line two slots in the o/p frame, to do this we use a serial to parallel converter

for example if u have one i/p line with data rate of 200kbps

and another (second) i/p line with data rate of 100kbps

we apply serial to parallel converter on the 1st one to change into two i/p lines with data rate of 100kbps each

3-Pulse-Stuffed TDM

it's used when the i/p lines data rates are NOT multiple integers of each other

we make the i/p line with largest data rate the dominant one and add dummy bits to the other i/p lines data rates to be equal to it

for example if u have one i/p line with data rate of 100kbps

and another (second) i/p line with data rate of 99kbps

we make the 1st one the dominant one and add 1kbps of dummy bits to the second one (99k + 1k) to be equal the first one