A pproximate model for cSMA/CD Simplified approximation for added insight ● Consider a s| otted system with“mini- slots” of duration2τ packet minislots If a node starts transmission at the beginning of a mini-slot, by the end of the mini-slot either No collision occurred and the rest of the transmission will be uninterrupted A collision occurred, but by the end of the mini-slot the channel would be idle again Hence a collision at most affects one mini-slot Eytan Modianoτ Approximate model for CSMA/CD • Simplified approximation for added insight • Consider a slotted system with “mini-slots” of duration 2τ −> 2τ<− <----------- 1 ----------------> packet minislots • If a node starts transmission at the beginning of a mini-slot, by the end of the mini-slot either – No collision occurred and the rest of the transmission will be uninterrupted – A collision occurred, but by the end of the mini-slot the channel would be idle again • Hence a collision at most affects one mini-slot Eytan Modiano Slide 4