A method and apparatus are disclosed whereby noise is introduced at one or more base stations in non-HSDPA cells into the uplink signal from one or more user devices. As a result, the apparent quality of the uplink channel in those cells will appear to be lower than the actual quality of that channel. The power control commands issued from the base station to the user device will, therefore, reflect this lower estimated channel quality and, as a result, the user device will follow power control commands from the base station in the HSDPA cell. Therefore, the transmit power of the user device will remain adequate to communicate with the base station in the HSDPA cell and, as a result, the UL and DL in the HSDPA cell will remain synchronized.