Convergence of application services in next-generation networks [Guest Editorial]

The next-generation network is based on an all-IP endto- end network-layer infrastructure that comprises access, backbone, and egress, using different underlying wired or wireless technologies, and is enabled with quality of service (QoS) capabilities. An ever expanding set of sophisticated application services will take advantage of the QoS-enabled connectivity infrastructure of next-generation networks. These application services, their variety, their ease of use through a large variety of intelligent enduser devices, and their convergence and interworking across multiple domains will constitute the hallmarks of success in the next-generation service universe. Rudimentary forms of some of these application services are already deployed over the Internet. They range from communication services (e.g., VoIP, video, IM, email), to entertainment services that involve content delivery (e.g., music on demand, low to medium quality video on demand, gaming), to a vast array of data and information services (browsing, searching, e-commerce, information retrieval, software distribution, etc.). Since the Internet currently is not QoS-enabled, these services are typically offered on a best effort basis, often with inconsistent or unpredictable quality and fragmented end-user experience. Furthermore, most applications today have a "stovepipe" nature; that is, they are offered independent of one another, each typically with its own user interface and other ancillary features like authentication, charging, and session management. This paradigm will begin to change in next-generation networks, first by enabling the applications to use the QoS capabilities of the underlying connectivity infrastructure to provide a consistently high-quality user experience. More significantly, however, applications will progressively lose their stovepipe nature to become increasingly more intertwined and composite, thereby becoming far more attractive and useful to the end user. This convergence, mash-up, blending, composition, and brokering of application services, and the reusable components or enablers that form the foundational building blocks for their realization across the domains of communication (IMS), entertainment (IPTV), information (web), and others, will constitute a defining, as well as differentiating, attribute of service architecture in next-generation networks.