A method of reducing power consumption is provided. The method includes categorizing a plurality of cells including a serving cell into an identified cell set and a non-identified cell set based on received power of the plurality of cells, measuring received power of the plurality of cells including the serving cell based on a first measurement period during a first time interval, determining whether received power of the serving cell is greater than a predefined threshold or whether a number of cells included in the identified cell set or a configuration of the plurality of cells changes, or if one of the received power of the serving cell is greater than the predefined threshold and if the number of cells included in the identified cell set or the configuration of the plurality of cells does not change, changing the first measurement period to a second measurement period.