create the end-user services. When there is a lack of a clear consecutive chain (which is the case in the Internet service area), 'value chain' might be replaced by 'value web'. 'Service provider' is not a very precise term, but it is used a lot, also in User data Business relationship Business relationship FAB = Actor-user User segments Content interface, with providers fulfilment, Retailers Life stage dimension assurance and Value/attitude dimension billing Business relationship Services, QoS, Security neutral to Application SM = Service Service providers Applications providers management Service enablers NM = Network management neutral to Control FP = Fundamental technical plans Core connectivity Carriers Access Access Figure 4.15 A horizontal network gives horizontal roles Understanding Changing Telecommunications - Building a Successful Telecom Business Terminal Other network(s) (CPN, if any) Service network, if any Content Content Service network External MM networks Network control and intelligence PLMN/PSTN/ISDN Access Core connectivity User information flow The reference model - distributed model to show network segmentation and reference points Figure 4.16 Reference points enhancing actor separation and cooperation - the target network interfaces are preferable this publication. Adding a further word, for example Internet service provider, creates clarification. One actor, e.g. Telia Sonera in Sweden-Finland, can take on many roles. Network providers or network operators own and operate access and core networks. They sell network capacity and quality of service to service providers and mobile virtual network operators (MVNOs). This relationship is explained in Section 4.4.1. Network providers have often global ambitions in order to leverage on economy of scale. Service providers own user subscriptions. They package services and sell them to their users. To be able to offer, handle and charge for compelling services they normally own and operate some kind of service networks. They purchase capacity and q