  Using instantaneous aggregate arrival rate as an admission control parameter
will contribute to either bandwidth under-utilization or over-utilization.
Being bursty in nature and variable in rate, video flows might encode any rate
between a range of minimum and maximum values. At the time the decision is
made, if the measured rate is at the minimum value, the bandwidth might be
over-utilized due to accepting more sessions than the link can accommodate. In
contrast, it might be under-utilized if the measured rate is at the maximum
value due to rejecting more sessions than the link can accommodate. The
burstiness can be taken into account by considering the past history of the
traffic. This paper investigates the suitability of the average aggregate
arrival rate instead of the instantaneous aggregate arrival rate for video
admission decisions. It establishes a mathematical model to predict the
relationship between the two rates. Simulation results confirm that the average
aggregate arrival rate is a more efficient decision factor for a small number
of flows. Although it has no additional advantage for moderate and large number
of flows, it still can stabilize the admission decision by smoothing the
burstiness of a set of the instantaneous rates (within the measurement period)
over a period of time.
