An NR communication system is used as an example. In NR, the terminal device may be in different states, and one of the states is a radio resource control connected (RRC_CONNECTED) state. In the RRC_CONNECTED state, the UE has established an RRC context, that is, the terminal device has established an RRC connection. In other words, a parameter necessary for communication between the terminal device and the radio access network device is known to both the terminal device and the radio access network device. The RRC_CONNECTED state is mainly used by the terminal device to transmit data.

Usually, a packet-based data stream is usually bursty. There is data transmission in a time period, but there is no data transmission in a following relatively long time period. Therefore, in NR, a discontinuous reception (DRX) processing procedure may be configured for the terminal device. When there is no data transmission, the terminal device may be enabled to stop monitoring a physical downlink control channel (PDCCH), to reduce power consumption, thereby increasing battery use time.

FIG. 2 is a schematic diagram of a discontinuous reception cycle according to an embodiment of this application. As shown in FIG. 2, in DRX, a network device may configure a DRX cycle for a terminal device in an RRC_CONNECTED state. The DRX cycle includes an “on duration” time range, and in the “on duration” time period, the terminal device may monitor a PDCCH. The terminal device starts an on duration timer (or referred to as drx-onDuration Timer) at a start location of each DRX cycle (that is, a start location of the “on duration” time period). The time range may be a time length of the on duration timer, and a range of the time length may be 1 millisecond to 1200 milliseconds (ms).