rvices Server (TWSS) [27] enables Telecom operators to provide third parties with controlled, reliable access to Telecom net- work capabilities such as location, messaging, presence, and call control. In particu- lar, the 3PCC (third-party call control) functionality of TWSS is used by Business Finder to initiate a SIP call between the devices of Linda and Chris. Telecom proxies can be used to compose mashups such as Business Finder involv- ing Telecom functionality and third-party services. A code sample is demonstrated in Figure 1.11 that combines the Location proxy in JavaScript format along with the Service Delivery Platforms Business Finder 2.0-your search results on Google maps Poligon B Barberà Santiga-Provasa del Valles Florida Bob is Free Poligon A la Llagosta Rating: Click To Call el Besos, Can Migjans Polizur Pla d'en Coll Clota Ripollet N-150 Cerdanyola del Valles adesbank BV-1411 Parc Tecnológic del Vallés BP-1314 Ferreria Santa Maria de Montcada Montce Santjoan Parc de Can Cuyas Sant Mateu Santelvira Can'Cerda Santa Coloma POWERED BY de Gramenet VISITOR PASS REQUIRED Welcome to Barcelona! To access the requested service during your visit you'll need to purchase a visitors pass. Available pass types are $10.00 pass $20.00 pass $50.00 Accept Decline Figure 1.8 (a) Business Finder mashup, (b) visitor pass prompt to activate a visitor account at runtime. Service Composition and Control Google Call-a-Cab Online charging Service composition system Diameter Ro (via SCL CEP) Telecom Web Session Service Server state Business Finder service SCL triggers Web 2.0 "Prompt" Widget 3rd party call and finalises charging according to control Charging response (via SCL CEP) SOA services rules JSR 116 Presence IMS Control Plane (NG Location Factory) Service Interaction e.g., SIP INVITE Figure 1.9 Call-a-Cab: device model. Google Maps service. This simple code receives updates on the location information and displays it on Google Maps; note that this currently has no application logic com- ponent. However, the code hig