UE states: RRC_CONNECTED, RRC_IDLE, RRC_INACTIVE

Three RRC States

5G NR defines three RRC states, which is a key improvement over 4G LTE that had only two. RRC_CONNECTED means the UE has an active RRC connection with a specific gNB, full radio resources are allocated, and data can flow immediately. RRC_IDLE means the UE has no RRC connection, uses minimum power, autonomously performs cell reselection, and monitors paging occasions to check if the network has data for it. The third state is entirely new to 5G.