On reliability in the performance analysis of cognitive radio networks

Satisfying the quality of service (QoS) requirements of users in the form of channel availability and ser-vice retainability within the resource limited environment has been a major problem in cognitive radio networks. In this connection, several research studies have been carried out in the literature to improve the QoS of users by proposing dynamic channel reservation algorithms. However, the studies have a number of limitations in their conceptual and mathematical modeling of channel availability and service retainability, which render their performance evaluation unreliable. In this paper, we address these lim-itations for leading to more realistic, reliable, and practically valid modeling. For conceptual modeling, we use connection availability in place of channel availability, motivated by the fact that the latter does not necessarily lead to a successful establishment of connection and, thus, is not a suitable performance indi-cator. For instance, obtaining a channel for transmission is of no avail if the intended receiver is inacces-sible. Similarly, we consider service retainability with accessibility/inaccessibility of the intended receiver incorporated. For mathematical modeling, we use CTMC and the resultant closed from expres-sions to include all the required states of channel availability yet unsuccessful connection establishment. Additionally, we derive closed form equations for channel availability and service retainability that are in exact conformance with the CTMC model. Results confirm that considering the impact of receiver's acces-sibility leads to performance difference for the channel availability and service retainability presented in the sate-of-the-art.(c) 2021 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Satisfying the QoS requirements of users is a major problem in cognitive radio networks. Existing research studies have limitations in their conceptual and mathematical modeling, leading to unreliable performance evaluation. This paper proposes a more realistic and reliable modeling approach by using connection availability instead of channel availability and considering the accessibility of the intended receiver.