Consider the star topology network:

H$1-$ H$3-$ H$4$

$|$ H$2$

where Hosts CPU speeds and receiving bandwidths are considered infinite, each link is $4$km and reliable propagation speed is $2*10^8$ m$/$s$.$

Given the transmitting bandwidth of $1$Mbps between H$1-$H$3$ and H$2-$H$3.$

If H$1$ and H$2$ each simultaneously start transmitting $20$ frames, $50$KB$/$frame$,$ to node H$3,$ how long it would take for node H$3$ to receive all frames. Show calculations.