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Wi-fi

Wi-Fi is a popular technology that allows an electronic device to exchange data wirelessly (using radio waves) over a computer network, including high-speed Internet connections. The term "Wi-Fi" is used in general English as a synonym for wireless local area network (WLAN).

A wireless network uses radio waves, just like phones, televisions and radios do. In fact, communication across a wireless network is a lot like two-way radio communication. A computer's wireless adapter translates data into a radio signal and transmits it using an antenna.

A wireless router receives the signal and decodes it. The router sends the information to the Internet using a physical, wired Ethernet connection. The process also works in reverse.

The radios used for WiFi communication are very similar to the radios used for walkie-talkies, cell phones and other devices. They can transmit and receive radio waves, convert 1s and 0s into radio waves and the radio waves back into 1s and 0s. But WiFi radios have a few notable differences from other radios: they transmit at frequencies of 2.4 GHz or 5 GHz. This frequency is considerably higher than the frequencies used for cell phones, walkie-talkies and televisions and allows the signal to carry more data.

A device that can use Wi-Fi (such as a personal computer, video-game console, smartphone, tablet, or digital audio player) can connect to a network resource such as the Internet via a wireless network access point. Such an access point (or hotspot) has a range of about 20 meters indoors and a greater range outdoors. Hotspot coverage can comprise an area as small as a single room with walls that block radio waves or as large as many square miles.

WiFi has a lot of advantages. Wireless networks are easy to set up and inexpensive. They're also unobtrusive - unless you're on the lookout for a place to use your laptop, you may not even notice when you're in a hotspot.

Then there’s also a Wi-Fi’s downside. Firstly, its range is rather limited. Unless an area has numerous hotspots, one has to be as close to the source of the signal as possible. Otherwise, the connection will be terrible. There are likewise security concerns involving the use of public Wi-Fi networks. Since these networks are purposely or unintentionally unsecure, malicious users can sniff the data of others that are sent and received in the network and use it for criminal purposes like identity theft; but this can be covered by having an antivirus program and a firewall set up on an individual’s computer.
Exercise 1. Answer the questions

1. 
   Which device is necessary to connect to the Internet using Wi Fi connection?
   
2. 
   Does it happen to WiFi users to experience interference and when?
   
3. 
   How many frequency bands can WiFi radios transmit on?
   
4. 
   Are there differences in frequencies between WiFi radios and cell phones, walkie talkies and televisions?
   
5. 
   What does wireless network look like?
   

Exercise 2. Fill in the blanks

adapters slot built-in gear wireless hotspots

1. 
   If you want to take advantage of public WiFi (….....) or start a wireless network in your home, the first thing you'll need to do is make sure your computer has the right (….......).
   
2. 
   Most new laptops and many new desktop computers come with built-in (…...) transmitters.
   
3. 
   If your laptop doesn't come with (…...) wireless transmitters, you can buy a wireless adapter that plugs into the PC card slot or USB port.
   
4. 
   Desktop computers can use USB adapters, or you can buy an adapter that plugs into the PCI (…..) inside the computer's case.
   
5. 
   Many of these (…..) can use more than one 802.11 standard.
   

Exercise 3. Translate into Russian
The name "WiFi" doesn't really stand for anything. Rather, it's a play on the term "hi-fi," which stands for high fidelity, an audio term for music recordings that faithfully recreate the sound of original performances.
Exercise 4. Translate into English

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1. 
   Так как все устройства имеют адаптеры, то они одновременно могут подключаться Интернет через рутер. Насколько я знаю, этот рутер уже устарел.
   
2. 
   Имеет ли это оборудование дополнительную защиту от несанкционированного подключения?
   
3. 
   Насколько мощный маршрутизатор установлен в Вашем кафе?
   
4. 
   Ваши междугородние автобусы оборудованы Wi-Fi?
   

Exercise 5.

Describe an idea of a technology similar to WiFi but with new functionality. Give examples of its usage and prove that it is innovative.

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Internet

People always wanted to communicate and share information. That was the main reason for the development of computer network.

Computer network is a group of computers that can interact by means of a shared communication link. There are two types of network:

• 
  Local area network (LAN) is a network where computers are connected together directly, usually by cable. It is used in offices etc.
  
• 
  Wide area network (WAN) is a network of local area networks connected together. The connection might be a cable or a mixture of cable, fiber optic, and satellite connectivity.
  

Modem (abbreviation for modulate / demodulate) is a device that allows computers to communicate over ordinary phone lines. There are two types of modems: internal and external. Internal means that modem goes inside your computer. External modem is outside your computer and must be plugged into it.

A server is a computer designed to provide various services for an entire network. It is typically either a workstation or a mainframe because it will usually be expected to handle far greater loads than ordinary desktop systems.

The roots of the Internet go to 1969, when the Defense Advanced Research Projects arm of the Department of Defense created ARPANET for research in networking. The work centered around the problem in the Department of Defense - how to keep military sites in communication across the country in the event of a nuclear war.

In the beginning research was the main goal of the system. In 1994 an explosion of direct connections to the Internet occurs. Not only universities, research companies and other organizations became part of the Internet, but many of small businesses and homes were connected.

The estimate for year 2000 was 40 million people connected to the Internet and the large majority were home connections in more than 50 countries.

The Internet provides many services. Among them:

• 
  E-mail You can send or receive electronic messages from anyone on the Internet. Anything that can be stored in text file can be mailed.
  
• 
  File Transfer. The File Transfer Protocol (FTP) provides for the copying of files from one computer to another.
  
• 
  Communication. You can communicate with the help of the Internet with one person or a group of persons simultaneously.
  
• 
  Information.
  

On the Internet all addresses / domain names refer to «electronic Addresses», e.g.:

person-id@computer name.domain name

There is never blank space between the components of the Internet address. User ids need not be unique (id - identification), e.g. two people with the same name can have it as login name as long as they operate on separate domains. But the domain name of the computer must be unique, however:

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austin@galaxi.isr.umd.edu, austin@euler.berkeley.edu

Austin is the person-id, «galaxy» and «euler» are computer names, «isr.umd.edu» and «berkeley.edu» are domain names. Domain names are composed of sub-domain names: esr, umd, edu.

In the computer address isr.umd.edu the sub-domain «edu» tells that the computer is located at an educational institution. The sub-domain name «umd» stands for the University of Maryland, and «isr» means the collection of computers at the Institute for System Research, at the University of Maryland.

If you want to send a message put down the word «mail» before the address.

Today computers are seen as indispensable tools not only for computation and typing but for communications. The merging of computation and communications is making essential changes to day-to-day business activities of engineers. Suppose an engineer belongs to a geographically dispersed team. He can:

• 
  Use the Internet / E-mail for day-to-day communications.
  
• 
  Conduct engineering analyses at remote sites.
  
• 
  Share results among the team members.
  
• 
  Participate joint ventures assembled over a network, and online bidding of projects etc.
  

The table summarizes commonly used sub-domain names:

Domain	Meaning
com	Commercial Organization
edu	Educational Organization
gov	Government
int	International Organization
mil	Military Organization
net	Networking Organization
org	Non-profit Organization
at	Austria
au	Australia
br	Brazil
ca	Canada
de	Germany (Deutschland)
dk	Denmark
fr	France
jP	Japan
nz	New Zealand
uk	United Kingdom (England, Scotland, Wales, Ireland)
ru	Russian Federation

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Exercise 1. Check up your understanding. Give full answers.

• 
  What is the Internet?
  
• 
  What is “computer network”?
  
• 
  Which types of network do you know?
  
• 
  Why do we need modem?
  
• 
  What are the «duties» of server?
  
• 
  What kind of computers are used as servers?
  
• 
  What can you tell about the roots of the Internet?
  
• 
  Which services provides the Internet?
  
• 
  Which of the internet services do you prefer to use mostly?
  
• 
  What does the FTP provide?
  
• 
  What does the domain name of the computer mean?
  
• 
  Does the Internet help you in your study or work? How?
  

Exercise 2. Retell the text briefly using the following expressions and terms:
network, LAN, WAN, modem, the Internet, server, the roots of the Internet, provide services, domain name.
Exercise 3. What's missing? If you are in doubt refer to the text. Take it into account that in each item the first letter of the missed word is used.

1. 
   N.... is a group of computers that can i.... by means of a shared communication link.
   
2. 
   M.... is a device that allows computers to communicate over ordinary phone lines.
   
3. 
   A server is either a w.... or a m.... because it will be expected to handle much more loads than ordinary desktop system.
   
4. 
   E..... modem is outside your computer and must be plugged into it.
   
5. 
   With the help of the Internet you can communicate with a group of persons s..... .
   
6. 
   If you are going to send a message write down the word «m....» before the address.
   

Exercise 4. Rearrange the words and get the right sentences.
1. information / to communicate / and / share / want / people /

2. plugged / is/it / your

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