In a UMTS Terrestrial Radio Access Network (UTRAN), a method of switching from a current common channel to a dedicated channel for a UE. The method comprises estimating the round trip delay for data packets travelling between the UE and a peer node with which the UE is communicating. The product of the estimated round trip delay and the bandwidth of the common channel or the dedicated channel is determined and a threshold defined on the basis of that product. A switch from the common channel to a dedicated channel is initiated when the fill level of the RLC buffer(s) in the UTRAN for the UE reaches or exceeds said threshold.