echnology becomes transparent; if a user's request for service is satisfied, few will notice the underlying technology. Now, most innovative applications tend towards transmission asymmetry (e.g. multimedia Internet). Thus, we can meet areas with small cell sizes and a high data asymmetry more appropriately 10 with TDD than FDD. The lower efficiency of FDD results from larger number of soft handovers in small cells, while the dynamic DL/UL resource allocation makes TDD more efficient. Hot spot Traffic Traffic Microcell Avg. traffic Microcell Microcell FDD Macrocell Figure 7.5 Combining FDD and TDD coverage. Thus, it seems reasonable to think that we do not need to wait for TDD until we need overall network capacity; we can exploit it at the introduction of UMTS in hot spot areas. This means that 3G coverage planning can benefit from TDD from the start. In 10 FDD needs 2 X 5 Mhz instead of 1 x 5 Mhz as for TDD in small cells with asymmetric traffic. Deploying 3G Networks this field study, we assume that TDD can apply to dense urban areas and concentrate on macrocell dimensioning for FDD or WCDMA. 7.6.2 Radio Network Parameter Assumptions Figure 7.6 illustrates the coverage within a geographical area. Logically, an operator or service provider will aim to have 99% coverage for the populated area while maximiz- ing the geographical coverage. On the other hand, the penetration of UMTS at the intro- duction will not necessarily include all populated 11 environments. Thus, starting in the main cities and suburban areas, 3G network coverage can progress in three phases, i.e. 50%, 75 (80)%, and 99%. For business strategic reasons within a region, e.g. it would be expedient to cover also major vacation centres even if these areas do not have per- manent population, but transitory during a quarter of the year. Which means a sound business case for the introduction of UMTS would start with more than just 50% cover- age of the populated area. With the assumptions above, in the following we outline key issues when designing a