 situation the main tool, that is to say the network, must permit flexibility and agility to respond to the actual development. This is a main reason for the 'horizontal network'. In addition there is an increased need for flexibility in the connected terminals, which leads to a development where services are downloaded to the terminals. This does not mean that the actors can ignore their services once they can provide a large flexibility. With a good 'service feeling' and professional marketing the actors can increase their market share. And the network is by no means self-adaptive to the actual service load. On the contrary, service control becomes a matter for terminals well as the network. This is because the services entail a number of attributes. Service implementation is treated in Chapter 8. A specific success factor in the network is the introduction of a service layer. Success Factors: Services 1 Östen Mäkitalo in Sweden has proposed the following criteria for successful services (also mentioned in Chapter 1): Sufficient security Sufficient QoS Sufficient bandwidth (sometimes included in QoS) Availability of terminals Sufficient coverage Sufficiently cheap and easy to use These requirements are considered later in this chapter. Success Factors: Services 2 Quoting Wireless World Research Forum services have to be attractive, intuitive and easy to use, with personalization and ubiquitous access. The services must also be developed easily, deployed quickly and, if necessary, altered efficiently. Understanding Changing Telecommunications - Building a Successful Telecom Business Regarding the easy-to-use goal there is a concept called 0-1-2-3 that is used by Ericsson. It can be explained as follows: 0. Manuals: no manual should be needed for a user to get started with mobile Internet services. Configuration parameters are automatically sent to the user's phone over the air. 1. One-button access to your personalized homepage: each user has a personalized portal home page that is automatically set up from the 