Network Types & Data Transmission

Network Types

Internet

The internet is not owned by any individual or group. The internet is a worldwide collection of interconnected networks, cooperating with each other to exchange information using common stadards.

 

Everything that you access online is located somewhere on the global internet. all of these internet destinations are connected to local networks that send and receive information through the internet.

 

 

Local Network

Local networks *come in all sizes. They can range from simple networks consisting of two computers, to networks connecting hundreds of thousands of devices

 

*come in : ~로 존재하다.

*come in all sizes : 모든 크기로 존재하다. = 다양한 크기로 존재한다.

 

Neteworks referred to as small office/home office (SOHO) networks.

SOHO networks let you share resources such as printers, documents, pictures, and music, between a few local u

 

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Data Transmission

Types of Personal Data

Volunteer data is data that you offer yourself. You realize the data is being collected about you, and you are agreeing to share it or to store it somewhere on the network.

 

Inferred data is data that you generate by your activities. You may not realize is actually being collected about you

 

for example, your credit card. Every place that you use your credit card keeps a record, and therefore, if you move about and go to different stores, things are being collected about you preferences, the places that you typically eat or shop

 

and also, information that helps pinpoint your location. For example, I'm  here in Portland today, and I used my ATM card. Now, I live in Florida So my bank has now data that indicates that I traveled from Florida to Portland 

 

Observed data

for example, your phone probably keeps track of your location. Most people have their location services on. That information is also being stored and is being transmitted to your carrier

 

So you have a lot of information out there that is being collected and stored

 

The Bit

All of data is stored and transmitted 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 represents the smallest piece of data. Humans interpret words and pictures, computers interpret only pattern of bits.

 

*abbreviation : 약어

*interpret : 해석하다

 

A bit is stored and transmitted as one of two passible discrete states.

Every input device will translate human interaction into binary code for the CPU to process and store. Every output device will take binary data and translate it back into human recognizable form. the computer itself, all data is processed and stored as binary.

 

Computers use binary codes to represent and interpret letters, numbers and special caracters with bits. 

 

ASCII, American Standard Code for Information Interchange

commonly used code, each character is represented by eight bits.

For example:

• Capital Letter :  A = 01000001 
• Number :  9 = 00111001
• Special character :  # = 00100011

Each group of eight bits is known as a byte.

 

 

Common Methods of Data Transmission

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. Media refers to the *physical medium on which the signals are transmitted. A signal consists of electrical or *optical patterns that are transmitted from one connected device to another.

 

*physical medium : 물리적 매체

*optical : 광학적

 

There are three common methods of signal transmission used in network:

Transmission is achieved by 

• Electrical signals - representing data as electrical pulses on *copper wire
• Optical signals - converting the electrical signals into light pulses
• Wireless signals - *using infrared, microwave, or radio waves through the air

*copper wire : 구리선

*using infrared : 적외선

 

homes and small businesses, network signals are transmitted across copper wires(cable) or Wi-Fi enabled wireless connecitons. Lager networks employ fiber-optic cables in oder to reliable carry signals for longer distances.