Analysis of queuing systems with multiple servers under athreshold-type scheduling

摘要

A queuing system with multiple servers of different rates under athreshold-type scheduling is analyzed. The authors derive the generalexpressions for state probabilities and the average queuing delay inwhich the conventional M/M/n queuing is also included as thespecial case of the zero-threshold policy. A numerical calculation iscarried out for a queuing system with three servers under threshold-typescheduling in order to consider the impact of the multiple thresholds onthe average queuing delay of the system. It is found that the averagequeuing delay of the queuing system with multiple servers of differentrates can be reduced under threshold-type scheduling by selecting thethreshold values appropriately. Threshold-type scheduling is moreeffective as the difference between the service rates becomes larger. Itis also shown that computer simulation results agree well with thetheoretical results