A Two-Layer Game Approach for Traffic Offloading in Unlicensed Spectrum

License assisted access (LAA) is considered as a solution to the challenge of satisfying high throughput requirement in future 5G. However, the throughput of both LAA and WiFi systems still need to be improved. In this paper, a two-layer Coalition-Auction Game-based Transaction (CAGT) mechanism is proposed to optimize the performance of the two systems. In the first layer, a coalition among Access Points (APs) is built to balance the WiFi stations and maximize the WiFi throughput. Next, an auction game between the LAA and WiFi systems is used to gain a win-win strategy. Simulation results demonstrate that the proposed scheme in this paper can improve the performance of both two systems effectively.