pplications based on user needs and the possibilities offered by the network. The FPs shown in Figures 3.2 and 3.21 are now insufficient and a number of service- oriented plans are added. The service, security and QoS plans embrace functions in all layers (e.g. security in numbering and routing, QoS over the air). QoS and security can be seen as attributes to the service. In fact, certain services, security and QoS requirements have existed before. One could for example argue that ordinary voice and associated supplementary and/or intelligent network services have been around for a long time. Security may have been represented Understanding Changing Telecommunications - Building a Successful Telecom Business User data FAB = Actor-user Charges User segments Content interface, with Life-style analysis provision fulfilment, Youth, or content assurance and Roles (Billing) life enhancement, reception billing executives etc. (peer) Services, Qos, Security SM = Service management Application logic, Resources (API) Tuning NM = Network ROCE etc. Layering FP impl management Stable economic Network service interfaces Processing Platform Fundamental service technical plans Network interfaces interfaces Investments Distribution Figure 3.25 A service part is added for client-server communication (the horizontal network will further be presented using a three-dimensional view) by for example intelligible crosstalk requirements. In the old analogue days an acceptable 'historical' quality of service required amplifiers to make it possible to reach a sufficient voice level without shouting. In the non-layered days of telecom this QoS type of require- ment resided in the transmission plan, since the transmission part was the deteriorating part worth mentioning. Considering the historical background, we only need to make the incorporation of the three plans more formal. A fourth plan may occur here: the charging plan. Initially both the control layer and service layer provide charging. On the management side a service management pla