e can often adjust all services to the same cell range by individually adjusting the emitted power of each service. Medium Data Rate Speech and Low Data Rate High Data Rate Figure 7.2 Transmission rates and coverage. 7.3.1 Circuit and Packet Switched Services When dimensioning a 3G network in the FDD mode, e.g. the number of concurrent channels derived to cope with the different service requirements becomes the main in- put of the link budget analysis. Thus, if we have to manage traffic beyond a cell loading of 30%, any small load variation will have direct impact on the cell radius. We then have to achieve a dimensioning to meet the peak traffic during the busy hour in order to obtain a stable network. This stability will depend on how we treat the different types of service, i.e. Real Time (RT) or Circuit Switched and Non Real Time (NRT) or packet switched types. 7.3.1.1 Circuit Switched (CS) To dimension capacity for CS services we can follow the classical approach, i.e. given the offered load (Erlangs) and the blocking rate, we derive from the traffic assumptions the offered traffic at the busy hour per cell (Erlang). Here we would assume the cell radius gets optimized iteratively with the link budget. Then, from Erlang B table we would determine the number of concurrent channels required during the busy hour for a given blocking rate. Although the traditional solution may allow us to estimate CS capacity easily, it may also over dimension the required number of channels. Thus, it seems imperative that we use the multi-service Erlang B formulation and pool the resources for better availability on demand. This implies that we offer the CS channels depending on the required num- ber, e.g. if one service requires 2 channels and the other 10, both can benefit from the pool, which may contain 20 channels. The latter would also imply that we could use different blocking rates for each service. For example, voice calls can tolerate degrada- tion better than video calls. 7.3.1.2 Packet Switched Services As in the CS,