Class Qsys_mapphc

java.lang.Object
jline.api.qsys.Qsys_mapphc

public final class Qsys_mapphc extends Object
The MAP/PH/c FCFS queue, solved exactly. THE STATE SPACE. With c identical servers the server identities carry no information, so the service phases are held as a MULTISET: a configuration is n = (n_1..n_ms) with sum(n) = k servers busy in phase i. There are binomial(ms+k-1,k) of them, the count of Asmussen and Moller (2001), against ms^k for the ordered space. Levels 0..c-1 are the boundary (level = servers busy), levels >= c repeat and carry the queue. THE WAITING TIME. An arrival that finds j customers waiting ahead of it waits for j+1 service completions, so Wq is the (j+1)-st event time of the configuration MAP (Lc, Cdep) started at the arrival-epoch configuration. Folding the matrix-geometric level distribution over j gives the LINEAR matrix ODE G'(t) = G Lj + R G Cj with G(0) = (I-R)^-1 kron(D1,I)/lambda and P(Wq > t) = pi_c G(t) e, so Wq is matrix-exponential. Its transform obeys the generalized Sylvester equation g(sI-Lj) - R g Cj = G(0), and every moment reuses that one operator with a different right-hand side. References: S. Asmussen and J.R. Moller, "Calculation of the steady state waiting time distribution in GI/PH/c and MAP/PH/c queues", Queueing Systems 37(1):9-29, 2001. D.P. Gaver, P.A. Jacobs, G. Latouche, "Finite birth-and-death models in randomly changing environments", Adv. Appl. Probab. 16:715-731, 1984.
  • Method Details

    • qsys_mapphc

      public static QsysMapPhcResult qsys_mapphc(Matrix D0, Matrix D1, Matrix alpha, Matrix S, int c)
    • qsys_mapphc

      public static QsysMapPhcResult qsys_mapphc(Matrix D0, Matrix D1, Matrix alpha, Matrix S, int c, int maxNumComp, int numWMoms, Matrix wPoints)
      Parameters:
      D0 - arrival MAP hidden block, order ma
      D1 - arrival MAP arrival block, order ma
      alpha - PH service initial vector, order ms
      S - PH service sub-generator, order ms
      c - number of servers
      maxNumComp - cap on the queue length probabilities returned
      numWMoms - how many waiting-time moments to return
      wPoints - times at which to evaluate P(Wq > t), or null
      Returns:
      the exact solution