Cognitive cooperative traffic offloading scheme over heterogeneous networks

Traffic offloading over heterogeneous networks allows the traffic to be offloaded between networks, in order to ease the strain on the overloaded network. In this paper, a cognitive cooperative traffic offloading scheme over heterogeneous networks is proposed. In the proposed scheme, the shifted users which are offloaded from the overloaded network to the under-loaded network are treated as the secondary users (SU) for the target under-loaded network, and the users in the under-loaded network are primary users (PU). SU cooperates with PU's transmission with a reward of access to the PU's spectrum. More importantly, Stackelberg game is applied to optimize the strategies of both under-loaded and overloaded networks, in order to ensure both of their utilities in terms of data rate and cost are maximized. Simulation results reveal that the proposed scheme improves the utility of the overloaded network, and enhances the user satisfaction and spectrum efficiency of the under-loaded network, which indicate the traffic is effectively offloaded from overloaded network to under-loaded network and at the same time the performance of under-loaded network is improved.