A communication line is divided in two identical channels each of which will

serve a packet traffic stream where all packets have equal transmission time T

and equal inter$-$arrival time R $>$ T$.$ Consider, alternatively, statistical

multiplexing of the two traffic streams by combining the two channels into a

single channel with transmission time T $/2$ for each packet. Show that the average

system time of a packet will be decreased from T to something between T $/2$ and

$3$T$/4,$ while the variance of waiting time in queue will be increased from $0$ to as

much as T

$2$

$/16.$