A radio base station (RBS) is described herein that detects when a high-speed downlink shared channel (HS-DSCH) data frame (110) is lost after it was transmitted by a radio network controller (RNC) over a transport link (Iub) towards the RBS (104). To accomplish this, the RBS (104) upon receiving a HS-DSCH data frame (110) inspects a frame sequence number (302) located within the received HS-DSCH data frame (110) to determine if the frame sequence number (302) is in sequence with a frame sequence number (302) located within a previously received HS-DSCH data frame (110). If the two frame sequence numbers (302) are not in sequence, then one or more HS-DSCH data frames (110) that were previously transmitted towards the radio base station (104) have been lost. If the radio base station (104) detects to many lost HS-DSCH data frames (110a), then it can correct the problem by reducing the bit rate of a certain HS user flow or by reducing the maximum bit rate for all of the HS traffic which is going to be sent by the radio network controller (102) over the transport link (106) to the radio base station (104).