This application discloses a method for compensating for a clock frequency deviation between two ends of a link, and a communication port. The method may be applied to a first port. The first port detects a quantity of protocol-aware signal extenders in a link between the first port and a second port, and generates a padding packet based on the quantity of protocol-aware signal extenders in the link. Then, the first port inserts the padding packet into a data stream to be sent to the second port.

A wireless transmit/receive unit (WTRU) may receive configuration information. The configuration information may include channel state information (CSI) reference signal (RS) (CSI-RS) resource configuration information and/or CSI feedback reporting configuration information. The WTRU may determine a downlink (DL) CSI estimate based on one or more CSI-RSs received in accordance with the CSI-RS resource configuration information. The WTRU may generate a CSI feedback report based on a comparison between the DL CSI estimate and historical DL CSI estimates. The WTRU may send the CSI feedback report.