Secondary Users’ Balking Strategies In Models Of Retrial Queues And Processor Sharing

With the constant development of wireless communication technology, the avail-able spectrum experiences a growing decrease, much less than decades ago. And this limit of resource is mainly caused by the unreasonable division of spectrum of different wireless access technology, which led to the rapid development cognitive radio net-works (CRN). The main research object of CRN is the secondary user(SU), and SU is capable of detecting spectrum usage, changing the communication parameters based on the self-adaption, and communicating on the spectrum band which is temporarily vacant. Besides, all these features show the flexibility and efficiency of CRN.The equilibrium balking strategy and related pricing problems of the SUs have become the research focus in recent years. Retrial queues and processor sharing (PS) are two important queueing models which attract great attention. Retrial queueing theory is widely used in the communication network, computer network and supply chain research, while PS models focus on describing network sharing problems and packet switching.The thesis mainly focuses on the equilibrium strategies of the SUs under certain conditions as retrial and PS respectively, and proposes two models:1. Equilibrium Secondary Users’Strategies in the Cognitive Radio Networks with constant retrialsIn the cognitive radio networks, the primary user (PU) has the priority to use the band while the SUs may occupy the band when it is available. The service for sec-ondary user will be interrupted when the PU arrives, and after that the SU transmitting information in the band will back off to the head of the retrial queue. The retrial phe-nomenon will exist when the first SU tries to cognize the service situation of the band. This thesis studied the equilibrium SUs’Strategies in CRN with constant retrials.2. Equilibrium balking strategies of Secondary Users in Cognitive Radio Network with processor sharingWhen a certain number of SUs are waiting for the band, the new entrants will expe-rience a longer waiting time. The advantage of PS model is that there is no waiting time for the new entrants, and it is worthy of discussion that what the situation will be when the SUs share the same channel based on CRN. This thesis integrates the traditional PS model and CRN model, then we study the band-sharing model with multiple SUs, finally obtain the thresholds strategy under the observable case, and Nash equilibrium strategy under the unobservable case.