tailieunhanh - Hiệu suất của hệ thống thông tin máy tính P4

IN the previous chapter we have already presented birth-death processes as an important class of CTMCs. In this chapter, we will see that a birth-death model can be used for analysing various types of elementary queueing stations. | Performance of Computer Communication Systems A Model-Based Approach. Boudewijn R. Haverkort Copyright 1998 John Wiley Sons Ltd ISBNs 0-471-97228-2 Hardback 0-470-84192-3 Electronic Part II Single-server queueing models Performance of Computer Communication Systems A Model-Based Approach. Boudewijn R. Haverkort Copyright 1998 John Wiley Sons Ltd ISBNs 0-471-97228-2 Hardback 0-470-84192-3 Electronic Chapter 4 M M 1 queueing models IN the previous chapter we have already presented birth-death processes as an important class of CTMCs. In this chapter we will see that a birth-death model can be used perfectly for analysing various types of elementary queueing stations. Furthermore by the special structure of the birth-death process the steady-state probability vector p can be expressed explicitly in terms of the model parameters thus making these models attractive to use. In Section we consider the solution of the most fundamental birth-death model an M M 1 queueing model with variable service and arrival rates. In principle all other queueing models discussed in this chapter are then derived from this model. In Section we deal with a single server queueing model with constant arrival and service rates. We then discuss the important PASTA property for queues with Poisson arrivals in Section it is used in the derivation of many interesting performance measures. The response time distribution in such a queueing model is addressed in Section . We then address multiserver queueing stations in Section and infinite-server queueing stations in Section . A comparison of a number of queueing stations with equal capacity but different structure is presented in Section . We address the issue of limited buffering space and the associated losses of jobs in Section for single servers and in Section for multi-server stations. In Section we address a queueing model in which the total number of customers is limited. We finally present a mean-value