A method includes: obtaining, by a first communications device, a first carrier, where the first carrier is used to transmit a first message and a second message; obtaining, by the first communications device, a first transmission resource and a second transmission resource of the first carrier, where the first transmission resource is used to send the first message, the second transmission resource is used to send the second message, and the first transmission resource and the second transmission resource are different transmission resources; sending, by the first communications device, the first message on the first transmission resource by using a first wireless access technology; and sending, by the first communications device, the second message on the second transmission resource by using a second wireless access technology, where the first wireless access technology and the second wireless access technology are different inter-device direct communications technologies.