use WAP to present the content efficiently on the screen. Then an operator might introduce positioning support in the network and now the applications developer can present the weather report differently depending on where the user is currently located. MMS is one of the key enablers. Content is created on top of MMS. Some content will be downloaded via WAP or created on the handset. With a camera built into the phone or attached to it, the user can more easily create appealing content on top of MMS. We need to view MMS as an enabler in order to create focus on the dearly needed content. Then there will be sites that not only host ring tones and logos showing Britney Spears but also advanced MMS shows with animations, pictures and sound clips that create early multimedia experiences on the nice colour screen handsets. 8.7.4 ADAPTATION AND BEARERS When combining service groups, service enablers and the stack from the QoS chapter, the peer-to-peer or client-server communication system in Figure 8.21 can be drawn. Because of space problems MPLS and RSVP are left out in this particular figure. Since the client and the server (terminal device and service network) cooperate in enabler creation, it is fair to draw the enabler as an end-to-end function. What now remains are the 'Economy of service' functions mentioned in Figure 8.18. As seen from Chapter 6 there are security protocols as well (IPsec, WEP 128, WTLS etc.) at different layers in the stack. See for example Figure 6.13. Tunnelling further adds to the complexity. To make the picture even more complete let us take another look at the service layer. OMA and others are working with web services, in particular for the service layer. Intro- duction of such technology makes service enablers accessible to any service provider. Among the web service protocols are WSFL, UDDI, WSDL, SOAP, XML and others. See Appendix 1. Every protocol belongs normally to a fundamental plan. 8.7.5 SERVICE IMPLEMENTATION SUPPORT IN THE SERVICE LAYER Among the six segments in the service g