| 摘要 |
A higher layer at a base station generates and passes messages to Layer 2, which generates and appends a CRC value to each message. The messages are encapsulated in frames at the physical layer, which generates and appends a CRC value to each frame. The base station transmits the frames on a control channel. The physical layer at a wireless device processes the control channel and decodes each received frame to obtain a decoded frame. The physical layer forwards the decoded frame to Layer 2, regardless of whether the frame passes or fails a CRC test. Layer 2 processes the decoded frame, even if the decoded frame fails the CRC test, to extract messages sent in the decoded frame. Layer 2 checks each extracted message based on its CRC value and forwards each message that passes the CRC test to the higher layer. |
