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1. Introduction In the last decade several wireless access technologies have emerged. Some of them are competing, most are complementary. Today it is clear that there will not be a single wireless access solution appropriate for all the application scenario. On the contrary, it is expected that many of them will coexist in heterogeneous wireless access systems. Users are willing to access the network infrastructure through the best available solution. This leads to the Always Best Connected (ABC) concept. Recently, there has been much buzz about ABC, however, a clear statement of the concepts involved is still missing. In fact there are many questions waiting for an answer. The first and most important regards the meaning of best. In fact, which is the best solution strictly depends on the application scenario, on the requirements and on the perspective (e.g., the best in the user perspective does not necessarily coincide with the best in the network operator perspective!). 2. Always Best Connected Concept The “Always Best Connected” concept, or ABC as it is also known, was traditionally the vision behind vertical handoff technologies from GSM, EDGE, GPRS or UMTS accesses and networks to unlicensed spectrum technologi