Data Communication Fundamentals

Module  Data Communication Fundamentals This module is concerned with some of the important issues of the physical layer, which provides services to the layer above it, namely the data link layer
. In the data link layer, the data consists of es and 1st, which are organized into frames to be sent through some transmission media
. It is necessary to convert this data into another entity called signal
. After introducing the fundamental model of communication, Lesson introduces the basic elements of communication such as data, signal and channel characteristics
. Different data types, concept of time domain and frequency domain representation of signal, various channel characteristics such as bandwidth, bit interval and bit rate of a digital signal are considered in this section
. Lesson  introduces different transmission media, which are broadly divided into two categories, namely guided and unguided media
. Typical characteristics and uses of each type of media starting from twisted-pair cables, coaxial cable, and optical fiber to line-of-sight and satellite communication have been covered in this lesson
. Lesson  will introduce various sources of impairments, such as attenuation, distortion and noise, that a signal suffers as it passes through a communication media
. This lesson also will introduce the concept of channel capacity, which specifies the amount of information that can be sent through a medium
. Lesson deals with the transmission of digital signals, which involves encoding of data
. Encoding of digital data involves two types of coding namely line coding and block coding
. Various line coding techniques such as uni polar, polar, and bipolar and block coding techniques are presented in this lesson
. Encoding of analog data involves conversion to digital form by using techniques like pulse code modulation and delta modulation, which are also discussed in this lesson
. Transmission of analog signals is discussed in Lesson 
. It is necessary to perform modulation to convert analog data to analog signal
. Various aspects of the three possible modulation techniques, namely amplitude, phase and frequency have been discussed in this lesson
. Similarly, to convert digital data to analog signal, possible approaches such as amplitude, phase and frequency shift keying have been covered in lesson