Investigating the effect of network service breakdown in multilayered cognitive communication system

In this paper a finite source retrial queueing model is considered to study the performance measures of a communication network subject to random system breakdowns. The sources of the queueing model represent the communication entities, which are divided into two groups: The first group of sources is the class of “Intelligent items”, where the items are able to sense and get information about the condition of the network environment, and so they are able to retry the started processing request in the case of special network communication issues. The second class is the “Dummy sources” (e.g. automated equipements), where the source item starts the network communication, but is not able to sense the changes in the network conditions, so it is unable to retry the transmission in the case of any errors.