The Internet has become the dominant platform for applications and services after two decades of impressive growth. Currently, the Internet is ubiquitous and is the key infrastructure of our information society with a high socio-economic value with its key role in supporting the operation of many cr ...

The Internet has become the dominant platform for applications and services after two decades of impressive growth. Currently, the Internet is ubiquitous and is the key infrastructure of our information society with a high socio-economic value with its key role in supporting the operation of many critical services in areas such as education, healthcare, transportation, finance, and e-business. Technological innovations in different fronts such as the Web (and its associated standards), wireless networks and pervasive computing have significantly enhanced the functionality and capabilities of new applications and services. Hardware developments including large performance gains and reducing cost have encouraged the emergence of a wide range of multimodal, multimedia applications on the Internet. In addition, new service-oriented architectures make it easier to integrate new applications and services, enabling a more compelling user experience and encouraging rapid innovation in terms of