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WIRELESS TAKES MANY FORMS

 

Radios work by using the electromagnetic spectrum to send information. When an electrical current travels through a wire it creates an electromagnetic field, sending out waves in all directions—rather like light, which is also a part of the spectrum but at much higher frequencies. An antenna and extra power allow the signal to be transmitted over long distances. The frequency of the wave can be changed so that signals do not interfere with one another, allowing more of the spectrum to be used.

 

Radio waves exist in nature, from sound and light to cosmic rays in space. The man-made sort can do things like transmit music or heat food in a microwave. At the low end of the spectrum are the frequencies used for things like television and mobile phones. The lower the frequency of the wave, the farther it can travel or penetrate physical objects. Thus FM radio at relatively high frequencies is used for local stations but does not travel far, whereas short-wave radio, at low frequencies, can stretch around the world.

 

Wireless technology can be split into five main sorts, roughly ranked by the distance that the signals travel. The top travellers are satellite communications such as the Global Positioning System (GPS). This is a constellation of 24 satellites, managed by the American armed forces, that constantly send out signals to devices on the ground. But the signals travel only one way, from satellite to device.

 

A little closer to home, and with signals going both ways, are “wide-area” mobile-phone technologies such as GSM or CDMA. Advanced “third-generation” (3G) versions include HSDPA* and LTE*, developed by the mobile-phone industry. A promising rival is WiMax, based on the Internet standard and supported by the computer industry. A third category takes in shorter-range signals used to connect things in a building or room. Examples include the popular Wi-Fi standard to access the Internet in hotels or airports, and Zigbee to link sensors. A new advance is ultra-wideband (UWB) technology, which uses very high frequencies at very short range to transmit huge amounts of data, as in sending video from an iPod-like device to a TV screen.

 

A fourth type connects things in a “personal-area network” or PAN. An example is Bluetooth, which is used to link mobile phones with earpieces. The last is near-field communications (NFC), where contact needs to be close, as in passes for buildings and public transport. A variant is radio-frequency identification (RFID) tags used by retailers and others.

 

* HSDPA - High-Speed Downlink Packet Access

* LTE - Long Term Evolution

 

Abbreviation Meaning
1. GSM  
2. UWB  
3. PAN  
4. NFC  
5. RFID  

 

Task 4. Find words or phrases in the text which mean the following:

 

1. intersect (paragraph 1) interfere
2. diapason (paragraph 1)  
3. device allows you to heat your food (paragraph 2)  
4. divided into (paragraph 3)  
5. consist of (paragraph 4)  
6. competitor (paragraph 4)  
7. seller (paragraph 5)  

Task 5. Which of these statements are true? Correct the false ones.



 

  1. The frequency of the wave can be changed.
  2. The higher the frequency of the wave, the farther it can travel or penetrate physical objects.
  3. Wireless technology can be split into four main sorts.
  4. Ultra-wideband (UWB) technology is a new advance.
  5. Bluetooth is used to link mobile phones with earpieces.
  6. Radio-frequency identification (RFID) tags are used by retailers.

Task 6.Watch the video “How Satellite Radio Works” and retell the main work principles of a satellite radio.

 

Task 7.Read the article and answer the questions.

 

  1. What does a wireless device refer to?
  2. What resources can a computer on the network share?
  3. What does a computer have to join a wireless LAN?
  4. What is Bluetooth?

 

WHAT IS A WIRELESS DEVICE?

 

A wireless device can refer to any kind of communications equipment that does not require a physical wire for relaying information to another device. Wireless headphones fitted with a receiver use either radio frequency (RF) or infrared technology to communicate with a transmitter that is connected to the sound source, say a television. In most cases, however, when someone refers to a wireless device, they are speaking of a networking device that can pass data to other wireless network gear without being physically connected.

 

In today's world, where people put a premium on staying connected to the Internet and to each other, there are several types of wireless technologies. In the home and office, wireless routers with built-in modems, hubs and switches broadcast a local area network (LAN) for computers in the area to join. Broadcasting distance varies widely depending on many factors, but a LAN generally spans 300 feet (91.44 m) or more. Any computer on the network can share resources that are connected to the network, including a high-speed Internet connection, printer or other office equipment.

 

In order to join a wireless LAN (WLAN), a computer must have a wireless network card or adapter installed. A network card is an internal wireless device manufactured to use the same language or protocol that wireless routers use. These protocols periodically evolve into new standards, however, causing compatibility issues in the interim. If a router uses a protocol that is not supported by an internal wireless device, an external wireless adapter can be used in an external port. The most common type is a USB dongle, but wireless network adapters are also available in ExpressCard® formats, giving laptop users a choice as to which port they would rather use.

 

Another type of wireless device might be part of a Personal Area Network (PAN). A PAN is created with Bluetooth technology, designed to connect personal digital devices over very short distances of just a few feet, though the standard extends to 30 feet (9.14 m).

 

Bluetooth is a very flexible and convenient type of network. It can be used to send print jobs from a laptop to a nearby printer without the hassle of setting up shared resources over a LAN. It is also used to connect Bluetooth-enabled cell phones, personal digital assistants (PDAs), or Apple products to each other or to other Bluetooth-enabled equipment including headsets, external speakers, or computers. Since Bluetooth uses a different frequency range than LANs, you can use a Bluetooth network "within" a LAN without interference.

Task 8.Work in small groups. Discuss these questions.

 

  1. Why is the technology called Bluetooth?
  2. How is Bluetooth used?
  3. Can Bluetooth products be used on aircraft?

Task 9. Check your answers (p. 69) and watch the video “What Is Bluetooth”.

 

Task 10. Prepare a short presentation on any sort of wireless technology.

 

ADDITIONAL TASKS.

RADIO SHOW “BUY ANS SELL”

Task 1a. In pairs, discuss the following questions.

 

  1. Do you own any of the things: a camera, a smartphone, a notebook, a computer?
  2. Approximately how much do they usually cost?
  3. What functions do these things usually have?
  4. Which ones would you like to have? Why?

 

Task 2a. You are going to listen to five teenagers. They are each taking part in a local radio show called “Buy and Sell”. In the show, people phone up and leave a message describing something that they want to buy second-hand or something that they want to sell. First, listen to their names, ages and phone numbers and write the information.

 

Name Age Phone number
   
   
   
   
   

 

Task 3a. Now listen to what they say next. Do they want to buy or sell something? Tick the correct column.

 

Buy Sell
 
 
 
 
 

Task 4a. Now listen to their complete messages. Circle the correct words or phrases to complete the notepad.

  1. Ticon X3-400 / X34-100 camera

Black / blue

Case included / extra

£25 / £20

  1. CD / DVD player

Must be easy to carry / use

With headphones / earphones

Not more than £50 / £25

  1. Video recorder / camera

Must/mustn’t have rechargeable batteries

Around £14 / £40

  1. mountain / racing bike

in very / fairly good condition

make: Taylor’s / Tiler’s

8 / 18 gears

Price: £65 / £56

  1. electric / electronic organizer

model: Handmate / Handmade Vdx

Price: £120 / £80

 

Task 5a. Listen one more time. For each question, write a word or short phrase.

 

Message 1  
What kind of photographs does he say the camera takes?  
Will he consider lowering the price?  
   
Message 2  
Why won’t she consider paying more?  
   
Message 3  
What does she not mind about?  
Who advised her to get one with rechargeable batteries?  
   
Message 4  
What kind of phone does he have?  
What reason does he give for selling his bike?  
How old is the bike?  
What depends on distance?  
   
Message 5  
When was her birthday?  
When did she get the organizer?  
How much will someone save by buying this organizer?  

 

Task 6a. Imagine you want to buy or sell something on “Buy and sell”. First fill in this information card. Don’t show anyone else your information.

 

 

Name:  
Age:  
Phone number:  
Buy or sell?  
Item:  
Make/model number:  
Age of product:  
Condition:  
Description:  
Any other information:  

 

Task 7a. As a class, take turns to say your messages. Imagine you are leaving the message on an answer phone so it can be played on the radio. When someone else is saying their message, note down their information on one of the cards below.

 

Name:  
Age:  
Phone number:  
Buy or sell?  
Item:  
Make/model number:  
Age of product:  
Condition:  
Description:  
Any other information:  

 

Name:  
Age:  
Phone number:  
Buy or sell?  
Item:  
Make/model number:  
Age of product:  
Condition:  
Description:  
Any other information:  

 

Answers:

 

Q: Why is the technology called Bluetooth?

A: The heart of the Bluetooth brand identity is the name, which refers to the Danish king Harald "Bluetooth" Blaatand who unified Denmark and Norway. In the beginning of the Bluetooth wireless technology era, Bluetooth was aimed at unifying the telecom and computing industries.

 

Q: How is Bluetooth used?

A: Bluetooth can be used to wirelessly synchronize and transfer data among devices. Bluetooth can be thought of as a cable replacement technology. Typical uses include automatically synchronizing contact and calendar information among desktop, notebook and palmtop computers without connecting cables. Bluetooth can also be used to access a network or the Internet with a notebook computer by connecting wirelessly to a cellular phone.

 

Q: Can Bluetooth products be used on aircraft?

A: The Federal Aviation Administration (FAA) and other aviation regulatory bodies worldwide are currently reviewing the use of Bluetooth products on private and commercial aircraft.

 


LESSON 3


Date: 2016-03-03; view: 232


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