Effect of class clustering on delay differentiation in priority scheduling

Priority scheduling is the most viable way to implement QoS differentiation in telecommunication networks. Most studies on priority scheduling do not take into account possible class clustering. In particular, they assume that different classes occur randomly and independently in the arrival stream of packets. In reality, however, packets of the same class may have the tendency to arrive in clusters. By using existing results, it is shown that class clustering may have a severe impact on the achievable delay differentiation in priority scheduling.