In the foregoing method, in the downlink EDT process, because the LCP priority of the first MAC CE is higher than the LCP priority of the first MAC SDU, the channel quality information may be preferentially sent, so that a success rate of sending the channel quality information can be increased.

In the first and the second possible scenarios, the reported channel quality information is carried by the first MAC CE, and does not involve an RRC layer. The terminal device may determine, at a MAC layer based on a TBS of the MAC PDU of the message 3, whether to send, in the message 3, the first MAC CE including the channel quality information.

In this embodiment of this application, because the LCP priority of the first MAC CE may be configured to be lower than an LCP priority of data of any logical channel, when the terminal device needs to send data, but the TBS of the MAC PDU is not sufficiently large for simultaneously sending the data and the first MAC CE, the terminal device preferentially sends the data, to ensure that data transmission is not affected by the reported channel quality information.

In addition, because the LCP priority of the first MAC CE may be configured to be higher than an LCP priority of data of any logical channel, when the terminal device needs to send data, but the TBS of the MAC PDU is not sufficiently large for simultaneously sending the data and the channel quality information MAC CE, the terminal device preferentially reports the channel quality information, and the data of the terminal device may be sent in subsequent transmission.