In this paper, we consider markovian retrial queue with two-way communication and unreliable server. Input process is Poisson with constant rate. Incoming calls that find the server busy join the orbit and reattempt to get the service after an exponentially distributed delay. In its idle time the server makes outgoing calls. There are multiple types of outgoing calls in the system. Service durations and rates of making outgoing calls are different and depend on type of outgoing call. The unsteadyness of the server is characterised by breakdown and restoration periods and its durations are exponentially distributed with rates depending on the server state.
Современные стохастические модели и проблемы актуарной математики, 25 сентября 2020, Карши, Узбекистан : тезисы докладов конференции. Карши, 2020. С. 40-41