hnical interworking Networks and Technologies Marketing expenses, Competitors Business Pricing Total market (all users) User needs Revenue User segments Market share, churn (regulations) Service offerings Operating expenses Other operators and service providers Financial calculations Interconnect ROCE, NPV ROI, Risk Investments Network Accounting Figure 3.29 The multi-operator environment also requires an interconnect plan which embraces many of the other plans, such as routing, QoS and numbering that UMTS provides the functions for both systems. Loose interworking means that the technologies work more autonomously. For the new generation network the following list gives examples of further plans under review: Technical framework/Network modelling Traffic handling Call processing Service management Call data management 3.9 THE CONNECTIVITY LAYER The three basic layering models or stacks are shown in Figure 3.30. From a management point of view a minimum number of networks is optimal. The possibility of handling all services in one network should justify the choice of just one network, shouldn't it? The only possible common transfer mode is IP, which is installed in practically all computers. The demands from voice services and data services are, however, very different and IP was designed for data. IP voice packets become quite different from IP data packets with much overhead (at least before header compression). See Figure 3.31. The answer to the question could be: 'One network eventually, but the convergence from many tailored Understanding Changing Telecommunications - Building a Successful Telecom Business TCP/IP Open systems Interconnection Common protocols Reference model Application Upper Application Presentation layers Session Error Transport Transport Destination Internet Network Error & Host-to- Could be Data link physical network any network Physical Physical Figure 3.30 Models for layered communication The voice packets are short to minimize delay and jitter Voice 64kb/s CS-Time slots Voice 64kb/s AA