Presentation

Plan:

1. Data transmission technologies

2. A) The idea of ​​data transmission over a distance

• Letters

• Messengers

• Devices emitting loud noises

B) Wired data transmission

• Can with wire

• First phone

• Telegraph

• Analog communication

C) Digital communication

• Types of connectors

• Baud rate and application

D) The birth of the internet

• History of the uprising

• Speed gain and range of applications

E) Wireless communication

• Femtocells, DECT, Bluetooth, Wi-Fi, 2,4Ghz, 2,5Ghz,

• Commercially used technologies: LTE, 5G, HSPA, 3G, 2G

F) Possible future technologies and summary

3. New words:

Access Channels, Active Satellite, ADSL - Asymmetric Digital Subscriber Loop, Asynchronous Communication, Audio Frequency, Bandwidth, Data Communications, Digital Transmission, Domain, Electromagnetic Spectrum, Encryption, Frequency, Gb – Gigabit, Interface, LAN, Microwave, Modem – Modulator, Packet, Protocol, Satellite Earth Terminal, Server, Synchronous Transmission:,

Script:

Hello, today I am going to show a short presentation about technology development over the years. To do this I need to log in, so give me a second.

OK, I’m in. So, the subject of the presentation is distance communication.

Let me start first with the definition:

„Any interpersonal communication in which the physical gap between the participants is beyond the physiological limits of unaided human perception.”

The definition may be unclear, but it means any communication of people who are not in sight.

Distance Communication includes communication by means of telephone, radio, letetrs and others. But it's in modern times – we will get to that.

For now, I will explain what synchronous and asynchronous communication is and then we'll look at the first ways to communicate at a distance.

So, asynchronous communication is any type of communication where one person provides information, and then there is a time delay before the recipients take in the information and offer their responses.

On the other hand, synchronous communication is when information or conversation can be sent and understood at the same time.

Before the invention of writing, the first ways for communicate synchronously with other people were loud sounds or smoke signs. But in those days synchronous communication was cumbersome, so a much better solution was to send messengers, who at first orally, then in written form, passed messages between people. Messengers mostly used animals to get to their destinations as quickly as possible.

Now let's get to the point. After some time, inventors began to create new designs to increase the distance between the interlocutors and to improve the speed of data transmission. The first step is the string cans used by children to this day. When the string between the cans is stretched taut, it allows voice-induced vibrations to be transmitted over a distance. This is an example of asynchronous communication.

Telephone, an instrument designed for the simultaneous transmission and reception of the human voice.

The invention of the telephone was the culmination of work done by many individuals, and led to an array of lawsuits relating to the patent claims of several individuals and numerous companies.

But Alexander Graham Bell is credited with developing the telephone because he received the first patent. After obtaining it in February 1876 (eighteen seventy six) in short time it has become the most widely used telecommunications device. Billions of telephones are in use around the world.

Meanwhile, some more great inventions like the telegraph were invented. This is where the concept of analog communication was born.

An analog signal is time-varying and generally bound to a range, but there is an infinite number of values within that continuous range. An analog signal uses a given property of the medium to convey the signal’s information, such as electricity moving through a wire. In an electrical signal, the voltage, current, or frequency of the signal may be varied to represent the information. Analog signals are often calculated responses to changes in light, sound, temperature, position, pressure, or other physical phenomena.

A digital signal is a signal that represents data as a sequence of discrete values. A digital signal can only take on one value from a finite set of possible values at a given time. With digital signals, the physical quantity representing the information can be many things.

In summary, an analog signal is a waveform of any value that we decode by assigning a value to the value. A digital signal, on the other hand, is a sequence of zeros and ones - that we can simply decode.

Analog signals are used in older equipment because they are simpler and less expensive to use since they do not require microprocessors to interpret the signal.

In 1962(nineteen sixtytwo), a scientist from M.I.T. and ARPA named Licklider proposed a solution to this problem: a “galactic network” of computers that could talk to one another. Such a network would enable government leaders to communicate even if the Soviets destroyed the telephone system.

In 1965(nineteen sixtyfive),, another M.I.T. scientist developed a way of sending information from one computer to another that he called “packet switching.” Packet switching breaks data down into blocks, or packets, before sending it to its destination. That way, each packet can take its own route from place to place. Without packet switching, the government’s computer network—now known as the ARPAnet—would have been just as open to enemy attacks as the phone system.

Is how it all started.

The Internet today is much more advanced and widespread. Leaving aside the complicated technical details, the internet is a collection of computers communicating with other devices. They form a network in which the largest access points connect to each other. They do this through wired (traditional and fibre optic) and wireless networks.

In 1894(eighteen ninetyfour), Guglielmo Marconi began developing a wireless telegraph system using radio waves, which had been known about since proof of their existence in 1888(eighteen eightyeight) by Heinrich Hertz, but discounted as a communication format since it seemed, at the time, to be a short range phenomenon. Marconi soon developed a system that was transmitting signals way beyond distances anyone could have predicted.

But, The wireless revolution began in the 1990s when Several technology companies created The Wireless Ethernet Compatibility Alliance. This event is considered to be the symbolic beginning of wireless networking.

Now, I will discuss some wireless technologies that you may be familiar with.

First one is in my opinion the most important because it has made possible to provide Internet access virtually anywhere in the world.

The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as mobile phones and tablets.

The maximum cell range implied by the GSM specification is about 25 km.

The technology developed rapidly and thanks to it we can enjoy the fifth generation today. It allows you to browse the internet at very high speed.

Next one is Bluetooth. This is technology that is still fitted as standard in smartphones today. It allows free data sharing directly to other device. The range doesn’t exceed 10 metres. Today, instead of file sharing, it is used to communicate with smart devices.

Next is Wi-Fi

It is a wireless networking technology that allows devices such as computers mobile devices (smart phones and wearables), and other equipment (printers and video cameras) to interface with the Internet. It allows these devices to exchange information.

Wi-Fi most commonly uses the 2.4 gigahertz (120 mm) and 5 gigahertz (60 mm) radio frequency; these bands are subdivided into multiple channels. Channels can be shared between networks but only one transmitter can locally transmit on a channel at any moment in time.

And the last one is special, because unlike previous technologies, infrared uses light waves instead of radio waves. Infrared was installed in telephones giving the possibility to share files directly. The maximum transmission speed is 115 kbps and the range is less than a metre. Because of this poor performance it has been replaced by Bluetooth.