Joint Spectrum Access and Pricing in Cognitive Radio Networks with Elastic Traffic

This paper studies the economic interactions between Secondary Users and Primary Operators in a Cognitive Radio Network scenario. Secondary Users transmit their traffic, eventually splitting it over multiple available frequency spectra, each owned by an independent primary network operator. Users are charged a fixed price per unit of bandwidth used, and face spectrum access costs. The transmission rate of each secondary user is assumed to be function of network congestion (like for TCP traffic) and the price per bandwidth unit. Primary operators sell spare bandwidth to secondary users, and set spectrum access prices to maximize their revenue. We provide sufficient conditions for the existence and uniqueness of the Nash equilibrium considering a peculiar class of spectrum pricing functions, viz. polynomial functions, which lead to efficient spectrum allocation, and we derive optimal price and spectrum allocation settings. Finally, we discuss numerical cognitive radio network examples that provide insights into the model´s solution.