Enabling technologies for the 'Always Best Connected' concept

'Always Best Connected' (ABC) is considered one of the main requirements for next generation networks. The ABC concept allows a person to have access to applications using the devices and network technologies that best suits his or her needs or profile at any time. Clearly, this requires the combination of a set of existing and new technologies. at all levels of the protocol stack, into one integrated system. In this paper, a considerable set of the technologies. that are expected to play a key role towards the ABC vision, are presented. Starting from a reference architecture, the paper describes the required enhancements at certain levels of a traditional protocol stack, as well as technologies for mobility and end-to-end Quality of Service (QoS) support. The paper concludes with a case stud), that reveals the advantages of the ABC concept. This article replaces a previously published version (Wireless Communications and Mobile Computing; 5(2): 175-191.