M/D/1 queue: Difference between revisions
No edit summary |
Gareth Jones (talk | contribs) →Finite capacity: clearer labelling of stationary result |
||
Line 17: | Line 17: | ||
==Finite capacity== |
==Finite capacity== |
||
===Stationary distribution=== |
|||
An analytical solution is described in <ref>{{cite jstor|3215497 }} </ref> |
|||
A stationary distribution for the number of customers in the queue and mean queue length can be computed using [[probability generating function]]s.<ref>{{cite jstor|3215497}}</ref> |
|||
===Transient solution=== |
===Transient solution=== |
||
Revision as of 06:47, 18 August 2013
In queueing theory, a discipline within the mathematical theory of probability, an M/D/1 queue represents the queue length in a system having a single server, where arrivals are determined by a Poisson process and job service times are fixed (deterministic). The model name is written in Kendall's notation.[1] Agner Krarup Erlang first published on this model in 1909, starting the subject of queueing theory.[2][3] An extension of this model with more than one server is the M/D/c queue.
Model definition
An M/D/1 queue is a stochastic process whose state space is the set {0,1,2,3,...} where the value corresponds to the number of customers in the system, including any currently in service.
- Arrivals occur at rate λ according to a Poisson process and move the process from state i to i + 1.
- Service times are deterministic time D (serving at rate μ = 1/D).
- A single server serves customers one at a time from the front of the queue, according to a first-come, first-served discipline. When the service is complete the customer leaves the queue and the number of customers in the system reduces by one.
- The buffer is of infinite size, so there is no limit on the number of customers it can contain.
Delay
Define ρ = λ/μ as the utilization; then the mean delay in an M/D/1 queue is[4]
Finite capacity
Stationary distribution
A stationary distribution for the number of customers in the queue and mean queue length can be computed using probability generating functions.[5]
Transient solution
The transient solution of an M/D/1 queue of finite capacity N, often written M/D/1/N, was published by Garcia et al in 2002.[6]
References
- ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1214/aoms/1177728975, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1214/aoms/1177728975
instead. - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1007/s11134-009-9147-4, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1007/s11134-009-9147-4
instead. - ^ "The theory of probabilities and telephone conversations" (PDF). Nyt Tidsskrift for Matematik B. 20: 33–39. 1909.
- ^ Cahn, Robert S. (1998). Wide Area Network Design:Concepts and Tools for Optimization. Morgan Kaufmann. p. 319. ISBN 1558604588.
- ^ Attention: This template ({{cite jstor}}) is deprecated. To cite the publication identified by jstor:3215497, please use {{cite journal}} with
|jstor=3215497
instead. - ^ Attention: This template ({{cite jstor}}) is deprecated. To cite the publication identified by jstor:3216008, please use {{cite journal}} with
|jstor=3216008
instead.