ond to those with high rates, e.g. 384 kbps in the PS mode within the DU and U areas. As mentioned in Section 7.6.8, the cell range decreases in areas where high transmission rates become predominant, e.g. DU and U. 7.8.2 Upper Bound Results Realizing a radio network for the minimum traffic and for the minimum subscriber growth in the immediate term will minimize investment costs. However, it may limit the flexibility in service strategy if rapid increase in subscribers and traffic occurs. Hence, in the following we assume upper limit bounds and project the network based on higher traffic profiles. This does not imply that deployed networks will be operating with the illustrated upper limits, specially at the introduction of UMTS. To simplify the propagation environments we group the six areas into three as follows: urban (DU + U); suburban (SU + IND), and rural (OP + FO). We increase traffic pro- files at the busy hour (BH) for every service and harmonize the subscriber base for the three areas as well. Clearly, we keep the assumptions on traffic patterns for the DL and UL, i.e. we assume higher volumes in the DL than in the UL. Such asymmetric traffic will allows us to exploit the benefits of the TDD technology in the dense areas by in- corporating micro- and picocells already at the introduction of UMTS, the latter assum- ing the technology has sufficient commercial maturity. Table 7.11 illustrates the con- solidated traffic for the three aforementioned propagation environments. In addition, it also shows the total traffic generated per area and the overall traffic proposed for the total number of subscribers proposed and referenced. The activity factor for LCD 12.2 (e.g. voice with AMR codec) is 0.5; for the other LCD and UDD services it is 1.0. The UMTS Network and Radio Access Technology Table 7.11 Upper Bound Traffic Flow with Consolidated Areas 75% population coverage reference projection 2005 Areas Urban (DU + U) Suburban (SU + IND) Rural (OP + FO) Subs no. 127000 663000 210000 Bearer (kbps) UL/DL UL/DL 