Example 63 includes apparatus of an eNodeB, the eNodeB configured to a assist an user equipment (UE) to perform inter-frequency and inter-public land mobile network (PLMN) discovery, the apparatus comprising one or more processors and memory configured to: process, for transmission to the UE, a serving PLMN system information block (SIB)19 for a carrier frequency of a serving PLMN of the UE to enable the UE to acquire inter-frequency and inter-PLMN discovery system information acquisition assistance signaling information from the SIB19; process, for transmission to the UE, using the inter-frequency and inter-PLMN discovery system information acquisition assistance signaling information, a non-serving PLMN SIB19 for one or more carrier frequencies of a non-serving PLMN to enable the UE identify inter-frequency and inter-PLMN discovery announcement rate information and monitoring control configuration information for the one or more carrier frequencies of the non-serving PLMN to enable the UE to perform device-to-device (D2D) discovery with a UE in the non-serving PLMN according to the inter-frequency and inter-PLMN discovery announcement rate information and monitoring control configuration information.