Optionally, device to device (D2D) communication may be performed between the terminal devices 120.

Optionally, the 5G system or 5G network may also be referred to as a new radio (NR) system or NR network.

FIG. 1 illustratively shows one network device and two terminal devices. Optionally, the communication system 100 may include multiple network devices, and the coverage of each network device may include another number of terminal devices, which is not limited in the embodiment of the present application.

In FIG. 1, the network device may be an access device, for example, it may be an access device in an NR-U system, such as 5G's new radio access technology (NR) base station (next generation Node B, gNB) or a small station, a micro station, and may also be a relay station, a transmission and reception point (TRP), a road side unit (RSU), etc.

The terminal device may also be called a mobile terminal, a user equipment (UE for short), an access terminal, a user unit, a user station, a mobile station, a mobile console, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. Specifically, it may be a smart phone, a cellular phone, a cordless phone, a personal digital assistant (PDA) device, a handheld device with wireless communication functions, or other processing devices connected to a wireless modem, an in-vehicle device, a wearable device, etc. In the embodiments of the present application, the terminal device has an interface for communicating with the network device (for example, a cellular network).