Methods, systems and apparatus for communications are provided. In the methods, a network device sends first indication information to a terminal device, where the first indication information indicates a first bandwidth part (BWP) that is to be activated, other than a primary BWP, to the terminal device, and the primary BWP is a BWP that remains activated between the terminal device and the network device. The network device communicates with the terminal device in an activated first BWP and the primary BWP.