A wireless communication system includes a plurality of WTRUs and a network. The plurality of WTRUs are pre-configured so that N WTRUs are identified to be in a specific paging group. Each WTRU in the paging group is configured to monitor related paging channels with an interval longer than the desired paging cycle of the network, thereby reducing power consumption. Each WTRU in the specific paging group takes turns in monitoring related paging channels so that the DRX scheme of the specific paging group is equivalent to the desired DRX scheme of the network, thereby reducing the likelihood of network signaling being missed or delayed.