Introduction to the transmission
1) Definition of the telecommunicationses:
The telecommunicationses comprise every transmission, emission or reception of marks them representatives signs, written, images, radioelectric, optical sounds of every nature through cables, means or other electromagnetic systems.
2) System of telecommunicationses:
It is with of finishes them, circuits and electromagnetic atmospheres in which propagano it marks containing them the information.
3) carrying Service and teleservizio:
A teleservizio it realizes the treatment and the transfer of the information, a carrying service instead is only taken care of its transfer.
4) perfect Transmission:
The system of transmission excited in entrance from marks
them sand(t) carries out a
perfect transmission if it marks them that it supplies in escape is 
that is only differs from that one in income
for a factor of delay and a factor of amplification, such factors are
famous a priori therefore do not constitute vehicle of information.
5) trasmissivi Means:
to) carrying lines of transmission or physicists
b) carrying drafts radio or radio
draft in both the cases of average is passed to you and linear.
6) Channel of perfect transmission:
It is constituted from trasmissivo means which it attenuates and therefore so that the gain of the draft is unitary, they must be present of the amplifiers is in transmission that in reception. It is important are dispositive absent not linear you.
7) Ways in order to execute N connections on a same tracing:
to) the information capacities from the N it marks them fiscal come grouped in marks them multiplato that propaga on an only physical way
b) to everyone of the N physical line marks is associated them one.