CS601 Midterm Notes 2020

CS601 Midterm Notes 2020 · 123 Topics: · CS601 Data Communication · ALI RAZA · Virtual University · Of Pakistan · Data Communication · Topic # 01

Introduction the course: Data communication course basically about communication.

Data: Data can take different forms but it is need for communication.

Communication as always been a human need just like food water, shirt, from the very begging of time. We cannot survive without communication. Communication in initial times took different forms.

Trends and advancements: Today the trends and advancements given us means and ways of Communication which are much better than actually use and what we use in initial time. We don't have those fires, anymore. We have got laptop, we have got smartphones, we have got ability to communicate to send text, to send audios, videos from point A to point B in split second today.

What is taught in this course?

In this course we will cover only those topics which are related to communication That What happened, if we want to send anything from point A to point B. We will go behind the scenes and we will understand and try to understand what happens.

What is not taught in this course?

we will not cover this course, we will not look at things like software applications, things like what happens when the information leaves your local machine or phone or sending device.

Tips and tricks to do well:

Text books and if u have text book so only read Data communication topic and Skip all those topics which are related to networking

Text and References:

Data Communication is a reference book if you want to buy you can easily buy. Data Communication is a very interesting Subject you will enjoy.

Topic # 02 · Introduction to Data · Communication:

It's all about Sharing of information between two parties. It can be remote or local.

Telecommunications:

Tele means distance, communication is the Sharing information. Communication at a distance includes telephony, telegraph and television etc.

Data communication:

Exchange of data between two devices via some form of transmission media. Both the source and transmission make up a source system. Whatever connects the Source system to the destination system is called Transmission system or medium. Then the Receiver receives the data and then as part of the destination system. It converts that data into format that Can be understood by the destination. we send data from workstation like laptop, Computer, mobile. Our modem took It and transfer to next device and then other reviver modem receive data and send to Server.

Topic # 03

Effectiveness of a Communication

We have already read about data Communication. Today we discuss some Characteristics of data communication. There are your characteristics: Delivery Accuracy Timeliness. Jitter

Delivery:

Delivery is the basic characteristics for any digital system. Delivery of information basically characterized that now well data communication is performing. Accuracy: The system must deliver the data accurately. Data that have been altered in a transmission and left uncorrected are unusable. So only accurate and efficient data should be sent to others.

Timeliness:

The system must deliver data in a timely manner. Data delivered late is useless. In the case of video and audio, timely delivery means delivering data as they are produced, In the same order that they are produced, and without significant delay. Jitter: Jitter refers to the variation in the packet arrival time. It is the uneven delay in the delivery of audio or video packets.

Topic # 04

In lecture no # 4 we just explore more about characteristics of data Communication, with the help of diagrams.

Topic # 05

Components of a Data Communication system

There are five components of a data communication system.

1. Sender 2. Receiver 3. Transmission medium 4. message 5. protocol

Message: Message is the information of data which you want to send point A to B. Sender: Sender is the device like computer, laptop, mobile phone, it can be mic if you make audio call, it can be camera of video call. Receivers: Receiver is the device which receive the data. It can be anything. Transmission medium: It is the physical path from De the sender to the receiver. There is also fixed transmission medium, like copper wire, it can be Libre optic cable. There is also wireless transmission medium it can be radio waves etc. Protocol: A protocol is a standard Set of rules that allow electronic devices to commune with each other. Those rules include what type of data may be transmitted, what commands are used to send and receive data and. how data transfers and confirms. you can think of a protocol as a spoken language.

Topic # 06

Data Representation and Data flow

As we know about data that data can be Text. Numbers. images. Audio, video. Data Representations: Data Representation refers to the form in which data is stored, processed and transmitted. Such as text Images into digital data that can be manipulated by electronic devices. Data flow: How data flows from point A to B. There are 3 modes that we are going to talk about simplex mode, Half-Duplex, full Duplex. Simplex: It's mean if we send data from one device to another is unidirectional, as in a one-way. Street, only one of the two devices on a link can transmit, the other can only receive. The simplex made is used to send data in one direction. Hall-Duplex: In half duplex mode, each station can both transmit and receive, but not at the same time. When one device is sending the other can only receive. full-duplex mode: In fall duplex modes transmission is simultaneously bidirections. The devices can transmit and receive Simultaneously.

Topic # 07

Networks

Networks: Interconnection of a set of devices Capable of communication. whether local or wide network. It consists of two components, Host and Connecting device. Host: A network host is a computer or the other device Connected to a computer network. A host may work as a server offering information resources, services and applications to users or other hosts on the network. Connecting Device: connecting devices are bridges between the different parts of a document that all the pieces together into one Coherent package. A network also must be able to meet a certain number of criteria.

1. Performance:
2. Reliability:
3. Security:

Performance: Performance of a network Pertains to the measure of service quality of Perceived by the user. The characteristics of performance are (Throughout, Delay). Reliability: The problem of sending a packet from a source to a destination as a single data link is considered. Reliable communication is defined as the delivery of a set of packets in order, and without any losses or duplicate. Security: Data Security is a process of Protecting files, database, and accounts on a network by adopting a set of controls, applications and techniques, that identify the relative importance of different data sets their sensitivity, regulatory compliance requirements and then applying appropriate protections to secure those resources. (Throughput): tells you how much data was transferred from a source at any given time. (Delay :-) network delay refers to the amount of time it takes.

Topic # 08

Physical Structure

Physical Structure consists of network. Attribute. link