Rally: Device-to-Device Content Sharing in LTE Networks as a Game

Even with modern physical-layer technologies in LTE networks, the capacity of cellular networks is still far from sufficient to satisfy the insatiable bandwidth demand of mobile applications. Owing to common interests among mobile users, Device-to-Device (D2D) communication has emerged as a viable alternative to offload cellular traffic, with the promise of substantially alleviating the need for cellular network bandwidth. In this paper, we first carry out an extensive theoretical analysis based on a game theoretic approach, and show that the objective of maximized cellular offloading is equivalent to maximizing the social welfare in a trading network, where the content to be shared is the commodity, and mobile users are buyers or sellers. We next design Rally, a set of distributed strategies that can converge to a sub game perfect Nash equilibrium in the content sharing game. Both our theoretical analyses and simulation results have shown the effectiveness of Rally, in that it can indeed maximize cellular traffic offloading through D2D communication.