a method and apparatus for detecting discontinued transmission frames in data frames received over a link or channel , is described , where a dtx frame is a frame that does not carry data and which is transmitted with zero power over the link or channel . the method calculates a data rate of a channel over which data frames are being transmitted , sets a threshold based on the data rate , and determines whether a received data frame is a dtx frame based on the threshold . the apparatus can effectively discriminate a case where a data frame is received as an erasure , and a case where a transmitted data frame is received as a dtx frame .