Abstract
Device-to-device (D2D) communication is offering smart phone users a choice to share files with each other without communicating with the cellular network. In this letter, we discuss the behaviors of two characters in the D2D data transaction model from an economic point of view: the data buyers who wish to buy a certain quantity of data, as well as the data sellers who wish to sell data through the D2D network. The optimal price and purchasing strategies are analyzed and deduced based on game theory.