There are only 2 stations, A and B in a bus

Question

1-persistence CSMA/CD network with TP =25.6 micro sec. and Tfr = 120 micro sec.

Station A has frame to send to Station B at time T=0.0 micro sec and station B sending a frame at 23.0 micro sec . Do frame collide?If yes, does station A and B detects collision.

 

Please answer this question with working.

Answer 1

Given $T_p=25.6 \mu s$ and $T_{fr}=120 \mu s$

Station A sends at $t=0$. B will receive this frame at $t=25.6 \mu s$. Meanwhile, B has already sent its own frame at $t=23 \mu s$. So collision occurs.

Now, since average transmission time for a frame is $T_{fr}=120 \mu s$, A will sent the last bit of the frame only at $t=120 \mu s$. A will receive the frame sent by B at $t=48.6 \mu s$. Thus A can detect collision at $t=48.6 \mu s$.

Take the case of B. B receives the frame sent by A at $t=25.6 \mu s$. B will sent last bit of its frame only at $t=143 \mu s$. So B will also detect collision at $t=25.6 \mu s$.