Abstract
As the technological scene of the 21st century changes rapidly, new facts for telecom and networks are coming to the front. Users’ growing demands for enhanced multimedia services on one hand and expanding infrastructure on the other lead to the realization of innovative networks, able to serve more subscribers more efficiently. Past technologies have failed to meet the present and immediate needs for integrated services and applications of real time traffic and high data volumes, high speed Internet, video on demand, and mobile communications everywhere and all the time (Chochliouros & Spiliopoulou, 2003). Globalization and deregulation of the market stimulate increased competition and call for integration of existing switching, optical, satellite, and wireless technologies (Commission of the European Communities, 2006). In the telecom industry new commercial opportunities are introduced. Internet and data services growth, in combination with increased maturity of packet-based technologies, results in the redrawing of traditional telecommunications architectures (Barnes, & Jackson, 2002). High quality, distributed, multiservice networks, with advanced features of flexibility and reliability, are now feasible, accommodating both circuit-switched voice and packet-switched data (Chochliouros & Spiliopoulou, 2005). This key architectural evolution in telecommunication core and access networks is described under the broad term “next generation networking (NGN).” Next generation networks, which are expected to be deployed in the markets over the next years, base their operation on packet transport of all information and services, voice, data, or multimedia. Encapsulation into packets is commonly implemented via the Internet protocol (IP), whereas services become independent of transport details, thus enabling improved functionality at the edge of the network, extreme scalability, and higher availability (European Commission, 2005). Nevertheless, the industry shift from centralized switches to “next generation” distributed, enhanced service platforms arises very important issues. Interoperability with existing networks is implicit, while great challenges appear in the conversion strategies towards implementing and exploiting the new architecture. Conventional communication systems need to evolve smoothly to NGN, through well-defined and carefully- planned transition procedures, in order for true convergence to take place.
TopBackground
According to the International Telecommunication Union (ITU) Study Group 13 Recommendation Y.2001 (ITU-T, 2004a), a NGN is defined as a packet-based network able to provide telecommunication services and make use of multiple broadband, quality-of-service (QoS)-enabled transport technologies. Consequently, such a “network” possesses various service-related functions that are all independent from any underlying transport-related technologies. Therefore, it enables unfettered access of users to competing providers and services of their choice. In addition, it can support generalized mobility which allows consistent and ubiquitous provision of a great portfolio of services to users.
The first provision of next generation networks was specified by the 3rd Generation Partnership Project (3GPP) with the IP multimedia subsystem (IMS) architecture (Grida Ben Yahia, Bertin, & Crespi, 2006a; Grida Ben Yahia, Bertin, Deschrevel, & Crespi, 2006b), which can be adapted to implement common services over various types of networks such as wireless local area networks (WLANs). The European Telecommunications Standards Institute (ETSI) Group of Telecommunication and Internet Converged Services and Protocols for Advanced Networking (TISPAN) also specified the interfaces and adaptations to control digital subscriber line (xDSL) access networks with IMS. In addition, TISPAN defined gradual public switched telephone network (PSTN) replacement by NGN technology. Oncoming NGN services need to be configured for coherent interaction with Internet service elements in order to provide a complete and integrated session-based service (European Commission, 2006).
Key Terms in this Chapter
Instructivism: A perspective on learning that places emphasis on the teacher in the role of an instructor that is in control of what is to be learned and how it is to be learned. The learner is the passive recipient of knowledge. Often referred to as teacher-centred learning environment. Learning as receiving content and exploring ideas in pursuit of teacher defined goals.
Reflective Practice: Refers to the notion that educators need to continuously think about and evaluate the effectiveness of the strategies and learning environment designs they are using.
Connectivism: A perspective on learning that views learning as a continual process of connecting, nurturing and maintaining information sources. The ability to see connections is a core skill. The learner’s aim is ultimately to maintain current and accurate knowledge. There is emphasis on informal learning. Learning as a continual and embedded process.
Social Constructivism: Founded in principles of constructivism, and developed by Lev Vygotsky, social constructivism emphasises the collaborative nature of learning. Social constructivism emphasises the role of language and culture in cognitive development.
Constructivism: A perspective on learning that places emphasis on the learners as being mentally active, building their own internal and individual representation of knowledge. Knowledge is actively constructed in response to interactions with environmental stimuli. Learning as self-directed.
Multimedia: “The entirely digital delivery of content presented by using an integrated combination of audio, video, images (two-dimensional, three-dimensional) and text” along with the capacity to support user interaction (Torrisi-Steele, 2004, p. 24).
OELE: Multimedia learning environments based on constructivist principles tend to be OELEs. OELE’s are open-ended in that they allow for the individual learner some degree of control in establishing learning goals and/or pathways chosen to achieve learning.