On the Retrial-Queuing Model for Strategic Access and Equilibrium-Joining Strategies of Cognitive Users in Cognitive-Radio Networks with Energy Harvesting

Kalpana Devarajan,Muthukrishnan Senthilkumar

doi:10.3390/en14082088

Abstract

This article studies the strategic access of single-server retrial queue with two types of customers, where priority is given according to their category. On the basis of this concept, a cognitive-radio network was developed as retrial queue with energy harvesting. Cognitive radio allows for a secondary user to opportunistically access the idle spectrum of a primary user (PU). Upon arrival of a primary user, the service given to the secondary user by the cognitive radio is interrupted, and the PU band is available for the primary user. After completion of service for the primary user, the PU band is again available to secondary users. Performance metrics are derived to study the equilibrium strategies of secondary users. A Stackelberg game was formulated and Nash equilibrium was derived for the noncooperative strategy of the secondary user. Game-theory concepts are incorporated with queuing theory ideas to obtain the net benefit for the noncooperative strategy and social benefit for cooperative strategy. Lastly, analytical results are verified with numerical examples, and the effects of energy-harvesting rate are discussed.

Highlights

This paper focuses on energy harvesting as a major factor in cognitive radio (CR) networks, the performance metrics and equilibrium-joining strategies [15] of secondary users with the help of queuing theory in addition to a game-theory aspect
Even though the PU band is in transmission for a secondary user, transmission is interrupted by the arrival of a primary user, and the PU band allocates the spectrum to the primary user
A CR network system was presented equipped with energy harvesting, treated as a retrial queue with two types of customers where priority is given according to their category

Summary

Introduction

In computer and telecommunication technologies, there exists a phenomenon called retry that often occurs to obtain a service, i.e., users try for their service while the server is serving another user. In these circumstances, they enter the waiting pool called orbit and try for their service after a random time period. For the detailed study about retrial queues one can refer Falin and Templeton [1]. These features apply for wireless communication systems

Objectives

Methods

Results

Discussion

Conclusion