Provided are a method and apparatus for sending data, a method and apparatus for processing data, as well as a network side device and a terminal. The method for sending data includes: performing first predetermined processing on data to be transmitted to obtain a first processing result; concatenating the first processing result with the data to be transmitted to obtain concatenated data; performing second predetermined processing on the concatenated data to obtain processed data; and transmitting a segment of data in the processed data and corresponding to a current data transmission of a network side device.