In accordance with an embodiment, a method includes: accessing, by a first terminal device based on a listen before talk (LBT) process, a channel and determining a channel occupancy time; determining, by the first terminal device, a sidelink resource in the channel occupancy time; and sending, by the first terminal device on the sidelink resource, sidelink information to a second terminal device, or receiving, on the sidelink resource, sidelink information from the second terminal device.