This work considers the legal fundamentals of EC telecommunications law. The liberalization process in die telecommunications sector was mainly developed by three important Court of Justice cases. Firstly, the British Telecommunications case1 was an early example of the application of competition rules in the telecommunications sector. Secondly, the Tetra Pak case" answered the question whether competition rules can be used to restrain anticompetitive practises in a particular market or market segment. The Court found that Tetra Pak was "in a situation comparable to that of holding a dominant position on the markets in question as a whole". In the literature, this is referred to as Associated Market Dominance. Thirdly, the Oscar Bronner v. Mediaprint3 case examined the essential facility doctrine, and that ruling, though restrictive, suggests that the doctrine may still be of relevance in the telecommunications field. In particular, the case showed that it is likely that an operator with strength on a related market (a mobile market compared to a fixed market) can be found to have control of an essential facility to which access is needed. In particular, incumbent fixed operators, which have benefited from a monopoly regime and its network, funded by the state through taxes, can be considered to control an essential facility. The study examines EC telecommunications law on its way to full liberalization, from the 1987 Green Paper to the fully liberalized market, which was in place in 1998. The considerable achievement over this ten-year period must be acknowledged. It is also shown how Article 86 EC was used by the Commission to force the liberalization process. The conclusion is drawn that "enforcement is the key to success", with some consideration being given to the energy and postal services. Part I ends with a more practical discussion of interconnection, which is considered to be the key element of Community telecommunications policy. In addition, the study examines consumer expectations in the converged fixed/mobile market. It shows that the majority of customers in the telecommunications market will actually subscribe to some form of converged service and that the regulator}' regime for that kind of service needs, therefore, to be carefully tailored to this new environment. As a result, the distinction between fixed and mobile will be less clear, and this requires that the regulatory framework adopts a consistent approach towards the two markets. The study further notes that given the complexity of the sector, consumer protection authorities seem to be willing to let specialist regulators handle the problems. It also discusses the possibility of applying competition rules in the area by, firstly, discussing the level of competition in the market for services and, secondly, the desirability of a market where operators and providers are encouraged to meet the needs of the customers in order to win their business. It continues by discussing the changeover from sector-specific regulation to the application of competition rules, with a special emphasis on significant market power. It also shows that the Commission needs to balance against the application of subsidiarity, tire need for greater certainty, as tire scope of the relevant product and service markets vary among tire different member states. Finally, tire study argues that conversion to reliance on competition rules is dependant on tire degree to which competition law can acquire tire analytical tools to deal with tire technical and commercial aspects of convergence in the field of mobile markets.