Session-level control in heterogeneous mobile radio networks with device-to-device connections

In the emerging fifth-generation mobile networks, the challenge of system capacity and user connection quality boosting becomes increasingly important. To this aim, it is possible to apply a novel direct communication technique that is built upon device-to-device (D2D) connectivity. Such heterogeneous interactions allow to offload data flows from a cellular network into the D2D system, which may operate in unlicensed frequencies. However, there emerge several problems with interference coordination and radio resource allocation. This work considers a model of the direct communication system with cellular assistance, which serves user-initiated data flows (sessions), as well as proposes an algorithm to control traffic offloading from a cellular network onto the D2D connections. Analytical and simulation results are offered to investigate this heterogeneous system with D2D communication capabilities.