Radio Resource Management for Device-to-Device Communications in Long Term Evolution Networks

Device-to-Device (D2D) communications enables direct and low-power communication among devices, leading to an increased and intelligent spatial reuse of radio resources and allowing to offload traffic from the primary data network. Furthermore, the proximity between devices allows data transfer with low delays and high rates without requiring extra power from devices’ batteries. Other benefits of D2D communication when underlying a conventional cellular network are the reuse gain and hop gain. However, in order to realize the potential gains of D2D communications as a secondary network, some key issues must be controlled. First, at each transmission request for a D2D-capable device, it is necessary to determine the neighbors, i.e., other D2D-capable devices that are in the vicinity of the latter and therefore may establish a D2D communication. Then, once neighbors are discovered and the target device is determined to be in the neighbors’ poll, the actual link (channel) conditions must be evaluated. Radio Resource Management (RRM) techniques are employed so that the co-channel interference caused in cellular devices is mitigated. Such techniques may be summarized as: band selection, grouping, mode selection, and power control. In this chapter, we focus our attention in the RRM for D2D communications underlying a LTE-like network, and the main RRM techniques to mitigate the co-channel interference. Namely, we draw the basis for grouping, mode selection, and power control techniques, and present some results that show their benefits.