 API interfaces interfaces (application programming interface, API) See Figure 9.5 and Chapter 3. The services provided by the service network respond to the needs of the actor: New marketing and sales channels. Efficient tools and development environments. Another related important concept is virtual home environment (VHE), offering ser- vice roaming. The VHE is defined as a concept for personalized service portability across network boundaries and between terminals. The idea with VHE is that subscribers are consistently presented with the same personalized features, user interface and services, regardless of their access network or terminal (within the capabilities of the terminal). Bundling sets of services forms personalized service portfolios for subscribers belonging to a home environment. VHE is further treated in Chapter 15. The standardized OSA interface needs to be secure, independent of vendor-specific solutions and independent of programming languages, operating systems etc. used in the service capabilities. Furthermore, the OSA interface is independent of the location within the home environment where service capabilities are implemented and independent of supported server capabilities in the network. 9.6.3 THE SERVICE CAPABILITY SERVICES (SCS) A kind of bridge between applications and network resources is required. Services and appli- cations negotiate the resources with the control layer over standardized APIs. Resources in Understanding Changing Telecommunications - Building a Successful Telecom Business Application 1 Application 2 Application N Service capability servers Packet-switched domain Network control layer Circuit-switched IP multimedia domain domain Figure 9.6 Bridge between applications and bearer resources the packet, circuit or multimedia domain can (ideally) be negotiated. The bridge is illustrated in Figure 9.6. API is explained in Chapter 3. See more below. The bridge consists of software enablers connected to a network. The original name was service capability services (SCS), whi