2 research outputs found
Signaling for Decentralized Routing in a Queueing Network
A discrete-time decentralized routing problem in a service system consisting
of two service stations and two controllers is investigated. Each controller is
affiliated with one station. Each station has an infinite size buffer.
Exogenous customer arrivals at each station occur with rate . Service
times at each station have rate . At any time, a controller can route one
of the customers waiting in its own station to the other station. Each
controller knows perfectly the queue length in its own station and observes the
exogenous arrivals to its own station as well as the arrivals of customers sent
from the other station. At the beginning, each controller has a probability
mass function (PMF) on the number of customers in the other station. These PMFs
are common knowledge between the two controllers. At each time a holding cost
is incurred at each station due to the customers waiting at that station. The
objective is to determine routing policies for the two controllers that
minimize either the total expected holding cost over a finite horizon or the
average cost per unit time over an infinite horizon. In this problem there is
implicit communication between the two controllers; whenever a controller
decides to send or not to send a customer from its own station to the other
station it communicates information about its queue length to the other
station. This implicit communication through control actions is referred to as
signaling in decentralized control. Signaling results in complex communication
and decision problems. In spite of the complexity of signaling involved, it is
shown that an optimal signaling strategy is described by a threshold policy
which depends on the common information between the two controllers; this
threshold policy is explicitly determined
Product Forms for FCFS Queueing Models with Arbitrary Server-Job Compatibilities: An Overview
In recent years a number of models involving different compatibilities
between jobs and servers in queueing systems, or between agents and resources
in matching systems, have been studied, and, under Markov assumptions and
appropriate stability conditions, the stationary distributions have been shown
to have product forms. We survey these results and show how, under an
appropriate detailed description of the state, many are corollaries of similar
results for the Order Independent Queue. We also discuss how to use the product
form results to determine distributions for steady-state response times.Comment: 32 pages, 5 figure