Introduction to networks

Define Network Data and Might Bit Lesson Objectives: Define Network Data and Might Bit Understand the data flow and the binary digit Understand methods of signal transmission used in network Bandwidth Vs. Throughput

Collect your candy..

Data

Data is a value that represents something.

DATA can be : Customer Data Personal Data Health Data Census Data

Alphabetic characters DATA can be represented as : Alphabetic characters Numbers Formulas Pictures

Alphabetic Characters Activity – Think & Share Classify the following words as in the following table: Student number – date of birth - icons – student name – charts and diagrams - city – subtraction– equation –bank a/c – pictures Data Type Examples Numbers Formulas Alphabetic Characters Pictures

Alphabetic Characters Think & Share ,,,, Set an example of theses data : Data Type Examples Numbers Formulas Alphabetic Characters Pictures Date of birth , bank account , student number subtraction- equation Student name, city, Pictures, icons, charts and diagrams

Using Data: Most people use networks to transmit their data in order to share with others or for long-term storage. Every time you hit ‘send’ or ‘share’ in an app or computer application, you are telling your device to send your data to a destination somewhere on the network. Sometimes data is being sent by your devices and you may not even be aware that this is happening. Examples of this are when you set up an automatic backup utility, or when your device automatically searches for the router in a wi-fi hotspot.

Activity P-20 What kind of data do you share on a day-to-day basis? Would you share different data online than you would in person?

Do you know which language does your computer speaks or understand ?? Discussion Do you know which language does your computer speaks or understand ??

The might Bit: Did you know that computers and networks only work with binary digits, zeros and ones? It can be difficult to imagine that all of our data is stored and sent as a series of bits. Each bit can only have one of two possible values, 0 or 1. The term bit is an abbreviation of ‘binary digit’ and it represents the smallest piece of data. Humans interpret words and pictures; computers interpret only patterns of bits.

The might Bit: A bit is stored and sent as one of two possible states. For example, a light switch can be either on or off; in binary representation, these states would correspond to 1 and 0 respectively. Wires carry information through the machine in the form of electricity. The two options that a computer uses with respect to this electrical information are ‘off’ and ‘on’. Off On

Data Flows: Input Devices : translate human interaction into binary code for the CPU to process and store Output Devices : will take binary data and translate it back into human recognizable form All data is processed and stored as binary

ASCII: A commonly used code is the American Standard Code for Information Interchange (ASCII). With ASCII, each character is represented by eight bits. For example: Capital letter: A = 01000001 Number: 9 = 00111001 Special character: # = 00100011 Each group of eight bits, such as the representations of letters and numbers above, is known as a byte.

ASCII: Codes can be used to represent almost any type of information digitally: computer data, graphics, photos, voice, video and music. Let’s look at an example. In figure you can see a binary decoder key. It gives an example of how computers might use ‘on’ and ‘off’ (ones and zeros) to represent letters. Each spot where you have a binary option is called a ‘binary digit’ or ‘bit’, for short.

Be Ready for the Activities >>

Book Activity ,,, P-22 Using the binary decoder, write the first letter of your name below. 1 1 1 1

Activity ,,, Look at the six images below. Work with a partner to figure out how you can encode them into binary code in such a way that another team can use the code to figure out what the image is that you selected. Choose an image with your partner. Figure out what your binary alphabet is going to be. Encode your image using your new binary alphabet. Trade your encoding with another team and see if you can figure out which picture they worked on. Choose a level - * Easy: Let the other team know what your encoding method was. * Tough: Have the other team guess your encoding method.

Getting bits moving: After the data is transformed into a series of bits, it must be converted into signals that can be sent across the network media to its destination. Network Media refers to the physical medium on which the signals are sent. Examples of media are: Copper wire Fiber-optic cable Electromagnetic waves through the air.

Methods of signal transmission used in network: In most homes and small businesses, network signals are transmitted across copper wires (cables) or wi-fi-enabled wireless connections. Larger networks employ fiber-optic cables in order to reliably carry signals for longer distances. Copper wires Fiber-optic Wi-fi

Methods of signal transmission used in network: Copper wires Fiber-optic Wi-fi Wireless signals – Transmission is achieved by using infrared, microwave, or radio waves through the air. Electrical signals – Transmission is achieved by representing data as electrical pulses on copper wire. Optical signals – Transmission is achieved by converting the electrical signals into light pulses.

Measuring bandwidth: Streaming a movie or playing a multi-player game requires reliable, fast connections. In order to support these ‘high-bandwidth’ applications, networks have to be capable of transmitting and receiving bits at a very high rate. In computer networks, bandwidth is used as a synonym for data transfer rate, the amount of data that can be carried from one point to another in a given time period (usually a second). Network bandwidth is usually expressed in bits per second (bps); modern networks typically have speeds measured in the millions of bits per second (megabits per second, or Mbps) or billions of bits per second (gigabits per second, or Gbps).

Measuring bandwidth: Different applications require different bandwidths: Types Bandwidth An instant message (such as WhatsApp) take less than 1,000 bits per second (bps) A voice over IP (VoIP) conversation requires 56 kilobits per second (Kbps) to sound smooth and clear Standard definition video (480p) works at 1 megabit per second (Mbps) HD video (720p) wants around 4 Mbps HDX (1080p) more than 7 Mbps.

Measuring bandwidth: Bandwidth is the rate or the capacity of an electrical signal that can be moved through a medium. (wire – cable – channel) Common bandwidth measurements are: Thousands of bits per second (kb/s) Millions of bits per second (Mb/s) Billions of bits per second (Gb/s) GB MB KB Introduction to networks

Measuring bandwidth: Physical media properties, current technologies and the laws of physics all play a role in determining available bandwidth. The table shows the commonly used units of measure for bandwidth.

Activity ,,,, Visit a website such as http://speedtest.net to check your internet speed. What are the speeds of the different networks listed below? Network Speed Internet speed at school   Internet speed on your mobile Internet speed next to your home internet Internet speed when you are very far from your router Introduction to networks

My Home Test Result.. Share me yours..

Home Activity ,,,, Book P-26 Why do you think the speed changes the further you move away from your wi-fi router? What other things do you think can affect the speed of your internet?

Home Activity ,,,, Why do you think the speed changes the further you move away from your wi-fi router? What other things do you think can affect the speed of your internet? The distance and amount of obstruction can effect the signal strength you receive. Type of router Network media (type of cables)

Throughput:

Throughput Vs Bandwidth: Bandwidth is the measure of the maximum speed you can get. throughput is the measure of the transfer of bits across the media over a given period of time. Or it can be the rate of successful message delivery over a communication channel

Home Activity ,,,, Book P-27 What factors do you think affect throughput? Channel width Encryption/ Decryption