User equipment, wherein the user equipment is in a device-to-device D2D communications system, and the user equipment comprises a receiver, a processor, and a transmitter, wherein: the receiver is configured to receive a monitoring parameter broadcast by a base station, wherein the monitoring parameter comprises an energy threshold corresponding to a busy resource, a reporting condition corresponding to the busy resource, an energy threshold corresponding to an idle resource, a reporting condition corresponding to the idle resource, a resource pool, at least one discovery time domain used to indicate that the user equipment should perform monitoring, wherein the discovery time domain corresponds to a given number of subframes, and a predetermined quantity of consecutive discovery time domains, wherein the predetermined quantity is greater than 1; the processor is configured to monitor energy of at least one discovery resource in the resource pool within the at least one discovery time domain; the processor is further configured to determine a busy resource and an idle resource in the at least one discovery time domain according to the energy of the at least one discovery resource, the energy threshold corresponding to the busy resource, and/or the energy threshold corresponding to the idle resource; the processor is further configured to generate a monitoring report when a proportion of the busy resource in the at least one discovery time domain during the predetermined quantity of consecutive discovery time domains meets the reporting condition corresponding to the busy resource, or when a proportion of the idle resource in the at least one discovery time domain throughout the predetermined quantity of consecutive discovery time domains meets the reporting condition corresponding to the idle resource, wherein the monitoring report comprises the proportion of the busy resource in the consecutive discovery time domains or the proportion of the idle resource in the consecutive discovery time domains; and the transmitter is configured to send the monitoring report to the base station. the receiver is configured to receive a monitoring parameter broadcast by a base station, wherein the monitoring parameter comprises an energy threshold corresponding to a busy resource, a reporting condition corresponding to the busy resource, an energy threshold corresponding to an idle resource, a reporting condition corresponding to the idle resource, a resource pool, at least one discovery time domain used to indicate that the user equipment should perform monitoring, wherein the discovery time domain corresponds to a given number of subframes, and a predetermined quantity of consecutive discovery time domains, wherein the predetermined quantity is greater than 1; the processor is configured to monitor energy of at least one discovery resource in the resource pool within the at least one discovery time domain; the processor is further configured to determine a busy resource and an idle resource in the at least one discovery time domain according to the energy of the at least one discovery resource, the energy threshold corresponding to the busy resource, and/or the energy threshold corresponding to the idle resource; the processor is further configured to generate a monitoring report when a proportion of the busy resource in the at least one discovery time domain during the predetermined quantity of consecutive discovery time domains meets the reporting condition corresponding to the busy resource, or when a proportion of the idle resource in the at least one discovery time domain throughout the predetermined quantity of consecutive discovery time domains meets the reporting condition corresponding to the idle resource, wherein the monitoring report comprises the proportion of the busy resource in the consecutive discovery time domains or the proportion of the idle resource in the consecutive discovery time domains; and the transmitter is configured to send the monitoring report to the base station.