Modeling Premium Service Low priority queue analysis –Approximation method 1 (coarse bound) Non-preemptive priority queue (Kleinrock bound) ER 2 = 1/  * 1/(1-  1 ) * 1/(1-  ) –Approximation method 2 (tight bound) Single M/M/1/K queue with delay busy periods Only approximates the priority queue ER 2 = E  2 +  B j (  2 ) Discussion on computing E  2 : –Is this a tighter or coarser bound.