A communication method and system, and a related apparatus. The communication method is applied to the communication system including a first device and a second device. In the communication method, the first device may indicate the second device to reserve a channel resource, and the second device does not perform data transmission on the reserved channel resource. This prevents the second device from occupying channel resources for long time, to release channel resources for a cellular communication system. The first device may schedule a terminal device other than the second device by using the released channel resources. This improves data transmission efficiency.