In this paper, we address the radio dimensioning issue that arises from the introduction of novel services in WCDMA networks. To investigate the impact and entailed limitations of the deployment of new services on the performance of the offered ones, we propose plain methods and a simulator for radio interface dimensioning. The tool (based on throughput estimates and snapshots of the system status) supports essential radio resource management functions, as admission control and packet scheduler with QoS differentiation. For each of the accessible services, we define the corresponding user satisfaction criterion, and performance results, at a given QoS, are presented as the maximum number of subscribers a WCDMA cell can satisfactorily accommodate. Several case studies on the deployment of PoC (Push to talk Over Cellular) in realistic mixed service scenarios are analyzed in this work. Simulation results show that no extra capacity is required for PoC launch.