Enabling D2D communications in LTE networks

Device-to-Device (D2D) communications provide the means to users of cellular networks for spatially reusing licensed spectrum by establishing direct connections. Considering the benefits for operators and consumers, a plethora of resource and interference management approaches in the literature deal with parallel cellular and D2D transmissions. However, this feature is not yet supported by modern cellular systems, such as the Long Term Evolution (LTE). The current paper targets at filling this gap by enabling D2D transmissions in LTE networks. Standardized LTE capabilities are utilized to provide a comprehensive framework on which existing or future resource and interference management schemes for D2D communications may be applied. The proposed framework is assessed under a moderate scenario where the cellular resource management policy is not affected. Results show that multiple D2D connections can be established in parallel to cellular uplink transmissions, while a satisfactory percentage of the cell region is available for spatial spectrum reuse.