A two-way communication system is modeled in this paper. A retrial queueing system
with a finite and an infinite sources is used in the model. The system has two sources.
The first source is finite, the second source is infinite. Jobs from the first source
are the primary jobs (requests). They can be called as first order job, as well. Jobs
from the second source are the secondary jobs. They can be called as second order
job, as well. In case of an idle server, the second order customers are called for
service. This situation is said as a special search for customers. The non-reliable
server is subject to random breakdowns. Two types of breakdowns are considered: the
regular breakdown, when the first or second order customer under service is sent back
to the orbit or the infinite source, respectively, and the catastrophic breakdown,
when all of the requests at the server and in the orbit are sent back to the corresponding
sources. The novelty of this paper is to investigate the effect of catastrophic breakdown
in a two-way communication environment. The goal is to determine the steady-state
probabilities and the system characteristics. The system balance equations are formulated
for different cases, but the analytic solution is very difficult. A software tool
is used instead. Figures illustrate the effect of the system parameters on the performance
measures in scenarios of regular and catastrophic breakdowns.
