25 research outputs found
Asymptotic Expansions for the Sojourn Time Distribution in the -PS Queue
We consider the queue with a processor sharing server. We study the
conditional sojourn time distribution, conditioned on the customer's service
requirement, as well as the unconditional distribution, in various asymptotic
limits. These include large time and/or large service request, and heavy
traffic, where the arrival rate is only slightly less than the service rate.
Our results demonstrate the possible tail behaviors of the unconditional
distribution, which was previously known in the cases and (where it
is purely exponential). We assume that the service density decays at least
exponentially fast. We use various methods for the asymptotic expansion of
integrals, such as the Laplace and saddle point methods.Comment: 45 page
Asymptotic Expansions for the Conditional Sojourn Time Distribution in the -PS Queue
We consider the queue with processor sharing. We study the
conditional sojourn time distribution, conditioned on the customer's service
requirement, in various asymptotic limits. These include large time and/or
large service request, and heavy traffic, where the arrival rate is only
slightly less than the service rate. The asymptotic formulas relate to, and
extend, some results of Morrison \cite{MO} and Flatto \cite{FL}.Comment: 30 pages, 3 figures and 1 tabl
A stochastic network with mobile users in heavy traffic
We consider a stochastic network with mobile users in a heavy-traffic regime.
We derive the scaling limit of the multi-dimensional queue length process and
prove a form of spatial state space collapse. The proof exploits a recent
result by Lambert and Simatos which provides a general principle to establish
scaling limits of regenerative processes based on the convergence of their
excursions. We also prove weak convergence of the sequences of stationary joint
queue length distributions and stationary sojourn times.Comment: Final version accepted for publication in Queueing Systems, Theory
and Application