In a data communication network (SYS) a first and second network site (BSS), (MS) communicate by sending a first data transmission (DT1) from the first network site (BSS) to a second network site (MS) and by sending a second data transmission (DT2) from said second network site (MS) to said first network site (BSS). In accordance with the invention data transmission characteristics (DTC1) of said first data transmission (DT1) are determined and radio resources for said data transmission (DT2) are allocated based on the determined first data transmission characteristics (DTC1). Thus, the radio resources for the second data transmission (DT2) are correlated with characteristics of the first data transmission (DT1) and thus delays in the data transmission between the first and second network site (BSS, MS) can be avoided. The invention finds particular application in data transmission networks, for example in a TCP/IP network, in which a link layer protocol context, for example a Temporary Block Flow (TBF), has to be set up for the data transmissions. In such applications the invention can reduce the data packet transmission delay by avoiding unnecessary TBF setup/tearing down procedures.