Wirelesscellularnetworksfeaturetwoemergingtechnologicaltrends.ThefirstisthedirectDevice-to-Device(D2D)communications,whichenablesdirectlinksbetweenthewirelessdevicesthatreutilizethecellularspectrumandradiointerface.ThesecondisthatofMachine-TypeCommunications(MTC),wheretheobjectiveistoatta