Patent attributes
When cell system information changes, a first terminal device receives, during on duration of the first terminal device, system information sent by a second terminal device, so that the first terminal device can receive the system information through a sidelink between the first terminal device and the second terminal device without a need to maintain a cellular link, thereby reducing complexity and power consumption of system information transmission. Alternatively, when cell system information changes and a first terminal device has only one receive radio frequency chain, the first terminal device obtains system information within a gap period of communication between the second terminal device and the first terminal device through a link between the first terminal device and a network device, so that the first terminal device maintains a cellular link only within the gap period, thereby reducing complexity and power consumption of system information transmission to some extent.
