Data offloading in load coupled networks: Solution characterization and convexity analysis

We provide a general framework for data offloading in a cellular network, where some demand of users is served in a complementary network. The complementary network is either a small-cell network that possibly shares the same resources as the cellular network, or a WiFi network that uses orthogonal resources. For a given demand served in a cellular network, the load, or the level of resource usage, of each cell depends in a non-linear manner on the load of other cells due to the mutual coupling of interference seen by one other. Taking into account this load-coupling effect, we choose the users´ demand to be served in the cellular network or the complementary network, so as to maximize a utility function. We establish conditions for which the optimization problem has a feasible solution and is convex, and hence tractable to numerical computations.