Communication method, communications apparatus, and communications system

A communication method, comprising:

• receiving, by a first network device, a first paging message, the first paging message being from a core network device when a paged first terminal device is in an idle state or being from a second network device when the paged first terminal device is in an inactive state, the first paging message being used to page the first terminal device, the first paging message comprising seventh information, the seventh information being related to a second network associated with the first paging message, the seventh information indicating a network identifier of the second network associated with the first paging message;
• wherein the first network device is configured to work for a first network, the first network being of a first network type and the second network being of a second network type;
• wherein the first network type is a public network and the second network type is a non-public network, or the first network type is a non-public network and the second network type is a public network.