4. Find synonyms of these words in the text:

follower; to offer; admiration; to assist; outside; jacket; to be invisible; leading.

5. Answer the questions to the text:

1. What have the proponents of the idea of the ‘sixth sense’ suggested?

2. What is the task of a true wearable computer?

3. How did early wearable computers work?

4. Who has finally created a design of a modern wearable computer? What does the idea consist of?

5. What is the MIT media lab’s model of wearable computing?

6. How many characteristics does a true wearable computer have? What are they?

7. What examples of this technology are available to the public at present?

6. Decide if the following sentences are true or false. Correct the false ones:

1. Hand-held devices, laptops and PDAs are not the same as wearable computers because they don’t operate like a natural part of a human body.

2. In 1960’s researches designed a computer allowing to overlay graphics onto special glasses and create a form of ‘mediated reality’.

3. Dr. Steve Mann’s recent model combines digital gloves, head-mounted camera and a projector all connected to a mobile phone.

4. One of the key characteristics of a wearable computer is that it doesn’t monopolize the user’s attention and cut him off from the outside world.

5. Nowadays a person can buy clothes with built-in controls or a keyboard.

7. Fill in the gaps using the information from the text:

People have always dreamed of wearable computers embedded directly into human being as if they were a ______. In other words, a true wearable computer should work like a ______.

The field of wearable computing began in ______. Early versions of such devices included ______, ______ and a ______ transferring images into a tactile grid for the ______ ______. Finally, ______ created a design allowing to ______ and create a form of ______. At present ______ is one of the key researches in this field. Their model combines such elements as ______, a ______ and a ______.

There are ______ basic characteristics of a wearable computer. It is ______ of the user’s attention, ______ to the user, ______ by the user, ______ to the environment and ______ to others.

Text 25. Wireless laNs

1. Discuss the following questions in pairs:

1. What is a computer network?

2. What are the benefits of connecting computers and peripherals in a network?

2. Match the following words and word combinations with their definitions and translate them into Russian:

1. wireless

2. interference

3. transceiver

4. indoor

5. LAN

6. protocol

a) situated in

b) any undesired signal that tends to interfere with the reception of radio waves

c) a network contained in a relatively small area

d) communicating without connecting wires or other material contacts

e) a device which transmits and receives radio or electronic signals

f) a set of rules that allows the exchange of information over a network

3. Read the text:

Wireless networking refers to technology that enables two or more computers to communicate using standard network protocols, but without network cabling. The current term however is generally used to mean wireless LANs. This technology has produced a number of affordable wireless solutions that are growing in popularity with business and schools as well as sophisticated applications where network wiring is impossible, such as in warehousing or point-of-sale handheld equipment.

Typically, a wireless LAN uses a frequency band where each unit is on a slightly different frequency, so that all units can communicate without interference. Usually there is a network access point (dedicated Hardware Access Point (HAP) or Software Access Point) and a PC that contains a transceiver and serves as the network hub. The hub computer can also be connected to a high-speed Internet service via DSL or cable. It has an antenna allowing it to communicate with wireless PCs up to several hundred feet away, depending on building configuration.

Each computer on the wireless network has an adapter with a transceiver so it can communicate with the access point. The adapter can be built-in (as is the case with some handheld computers), or mounted on a PC card (for laptops) or an ISA card (for desktop PCs) or connected to a USB port.

Simple home wireless LANs can be set up as a “peer network” where any two units can communicate directly with each other without going through an access point or hub. Applications needing Internet access (such as e-mail and Web browsers) can connect to the PC that has the Internet cable or DSL connection.

Several protocols or standards have been developed for wireless LANs. The most common today is IEEE 802.11b, also called WiFi with speeds up to 11 mbps transmitting on 2.4 GHz band. Although that would seem to be fast enough for most applications, there are the alternatives, 802.11g (with speeds up to 54 mbps) and a new 802.11n that theoretically can offer speeds up to 540 mbps. Since IEEE 802.11n uses the unlicensed 5 GHz frequency range it is not susceptible to interference from other devices.

Another wireless protocol called Bluetooth has been embedded in a variety of handheld computers, appliances, and other devices. It provides a wireless connection at speeds up to 1 MB/second.

The range of the wireless network can vary depending on the environment. Typical indoor ranges are 150-300 feet, but can be shorter if the building construction interferes with radio transmissions. Longer ranges are possible, but performance will degrade with distance. Outdoor ranges are quoted up to 1000 feet. There are ways to extend the basic operating range of Wireless communications, by using more than a single access point.

Using suitable radio frequencies to carry data among computers on a local network has several advantages. The trouble and expense of running cables (such as for Ethernet) in older buildings and homes can be avoided. With a wireless LAN a user could work with a laptop in the garden while still having access to a high-speed Internet connection. Moreover, a wireless LAN can help workers who have to move around within the building do their jobs. Examples might include physicians or nurses entering patient data in a hospital.