  This thesis will be focused on the classical capacity of quantum channels,
one of the first areas treated by quantum information theorists. The problem is
fairly solved since some years. Nevertheless, this work will give me a reason
to introduce a consistent formalism of the quantum theory, as well as to review
fundamental facts about quantum non-locality and how it can be used to enhance
communication. Moreover, this reflects my dwelling in the spirit of classical
information theory, and it is intended to be a starting point towards a
thorough study of how quantum technologies can help to shape the future of
telecommunications.
  Whenever it was possible, heuristic reasonings were introduced instead of
rigorous mathematical proofs. This finds an explanation in that I am a
self-taught neophyte in the field, and just about every time I came across a
new concept, physical arguments were always more compelling to me than just
maths. The technical content of the thesis is twofold. On one hand, a quadratic
classification based on optimization programs that I devised for distinguishing
entangled states is presented in Chapter 4. In second place, a less difficult
yet I hope equally interesting technical part consists of versions of some
proofs throughout the text.
