This video explains the basic principle of direct discovery: how a device sends (announces) and receives (monitors) a discovery message on the uplink frequency using defined resource pools. It also demonstrates effective RF measurements based on the R&S®CMW500 wideband radio communication tester. Since the R&S®CMW500 emulates the LTE network and the receiving device simultaneously, the correct sending of the discovery message can be verified in addition.
Direct discovery is part of LTE device-to-device proximity services (LTE D2D ProSe) standardized in 3GPP Release 12. This feature enables a device to discover what is in its close proximity in a power efficient way.