riptions, marketing, sales, after-sales, bundling of offerings, customer care and invoicing. They sell handsets and other customer premises equipment in shops. Today this role is often part of the activities of the network operators, but it is sup- posed to become more and more independent. One-stop shopping is often part of the business idea. The TINA-C international body includes this role. The TINA business model from 1999 defines the following business roles: The consumer role. The broker role, which enables other business roles to locate service providers. The retailer role, which is concerned with providing services to the consumer role. The third-party provider role, which is concerned with providing services to retailers or other third-party providers, but not directly to consumers. The connectivity provider, which owns a network and provides connectivity services over it to other business roles. Example 2: The Mobile Virtual Network Operator (MVNO). An MVNO offers mobile subscription and transport service to end users, but does not have a licensed allocation of spectrum. The host network operator owning a spectrum license is supposed to be willing or forced to open his access to other players. See also section 4.4.2. An MVNO can have any background: fixed operator; mobile operator going for new markets; media group content provider; portal provider; content aggregator; bank etc. An MVNO competes with service differentiation and a branded name as the main weapons. Example 3: Horizontal layer players in the core connectivity network. Common names are carriers and transport provider. See Figure 4.24. An example is the carrier MCI, offering as an example ATM PVC ABR, ATM PVC VBRnrt (variable bit rate, non real time) and ATM CBR (constant bit rate). This is an example of network internal services. Understanding Changing Telecommunications - Building a Successful Telecom Business Transfer modes Voice 64kb/s CS (Time slots) Voice 64kb/s AAL1 Voice compressed AAL2 Internet Data AAL5 Data IP Voice IP Circuit Data