N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 2 - Data Communications Basics and Legacy Technologies                                                 Slide 6 of 45 _________________                                                                                  __________

                             Building Blocks - Information Signal Transmission

                                          An Analogue Signal    

                                          A Digital Signal      

_________________                                                                                  __________

The information signals are in two forms: Analogue and digital. The Public Switched Telephone Networks (PSTN) and the TV broadcasting systems still use Analogue signal transmission and are gradually moving towards digital transmission.

An analogue signal is continuous in nature i.e. it has continuous lowest and highest frequencies with power. It can be amplified and transmitted over the copper, Cable, Optical fiber and wireless facilities.

                               
                                                Analogue Signal

A digital signal is discontinuous and discreet in nature i.e. it does not have all the frequencies and the strength of the signal located on discreet frequencies. It can be regenerated and transmitted over the Copper, Cable, Optical fiber and wireless facilities.

                               
                                                  Digital Signal