The task of this paper is to derive some basic relations between pilot measurements and dedicated traffic channel (DTCH) performance. It has been demonstrated that E_c/I₀ alone does not provide enough information about the performance of dedicated channels. At least the cell load of the node B, expressed by the transmitted signal strength indicator (TSSI), must also be known. For a target cell load, a certain minimal E_c/I₀ is required to provide the quality of service given by the target block error rate (BLER). This value can be derived from the equations stated in the paper and from physical layer simulation results. Also some hints on how this concept can be used in cell planning are given.