Transmission parameter determination method, terminal device and network device

A method for transmission parameter determination, comprising:

• determining, by a first terminal device, a transmission parameter of the first terminal device according to a channel busy ratio (CBR), a priority of a service to be transmitted and a first mapping relationship, the first mapping relationship being used to indicate a correspondence among CBRs, priorities of services and transmission parameters of the first terminal device, wherein the transmission parameters of the first terminal device comprise a first transmission parameter and a second transmission parameter,
• acquiring, by the first terminal device, at least one proportion coefficient;
• determining, by the first terminal device, the second transmission parameter according to the CBR and the priority of the service to be transmitted;
• and
• processing, by the first terminal device, the second transmission parameter using the at least one proportion coefficient to obtain the first transmission parameter,
• wherein the transmission parameter of the first terminal device further comprises a modulation and coding scheme (MCS) index, an MCS table corresponding to the MCS index of the first terminal device is different from an MCS table corresponding to an MCS index of a second terminal device, and the second terminal device is a terminal device supporting a version of a communication protocol different from a version of a communication protocol supported by the first terminal device.