  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 paper, 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.
