Survey of Spectrum Sharing for Inter-Technology Coexistence

Increasing capacity demands in emerging wireless technologies are expected to be met by network densification and spectrum bands open to multiple technologies. These will, in turn, increase the level of interference and also result in more complex inter-technology interactions, which will need to be managed through spectrum sharing mechanisms. Consequently, novel spectrum sharing mechanisms should be designed to allow spectrum access for multiple technologies, while efficiently utilizing the spectrum resources overall. Importantly, it is not trivial to design such efficient mechanisms, not only due to technical aspects, but also due to regulatory and business model constraints. In this survey we address spectrum sharing mechanisms for wireless inter-technology coexistence by means of a technology circle that incorporates in a unified, system-level view the technical and non-technical aspects. We thus systematically explore the spectrum sharing design space consisting of parameters at different layers. Using this framework, we present a literature review on inter-technology coexistence with a focus on wireless technologies with equal spectrum access rights, i.e. (i) primary/primary, (ii) secondary/secondary, and (iii) technologies operating in a spectrum commons. Moreover, we reflect on our literature review to identify possible spectrum sharing design solutions and performance evaluation approaches useful for future coexistence cases. Finally, we discuss spectrum sharing design challenges and suggest future research directions

A Survey on Dynamic Spectrum Sharing Using Game Theory in Cognitive Radio Networks

Due to the tremendous increase in wireless data traffic, a usable radio spectrum is quickly being depleted. Current Fixed Spectrum Allocation (FSA) strategy give rise to the problem of spectrum scarcity and underutilization. Cognitive Radio (CR) is proposed as a new wireless paradigm to overcome the spectrum underutilization problem. CR is a promising technology which for future wireless communications. CRs can change its operating parameters intelligently in real time to account for dynamic changes in a wireless environment. CR enables a technique called Dynamic Spectrum Allocation (DSA) where the users are able to access unlicensed bands opportunistically. Since idle spectrum from PU is a valuable commodity, many cognitive users will be competing for it simultaneously. Therefore, there arises competition among the users. Users may be only concerned about maximizing their own benefits by behaving rationally and selfishly. Thus spectrum allocation problem falls under NP-hard complex based on its complexity to solve. Out of several solution approaches, Game theory is found to be an efficient mathematical tool since it deals with solving the conflicts among the users. This survey is aimed at providing a comprehensive overview on dynamic spectrum allocation using game theory