Wireless Trends

Name :Class :

Prateek Ahuja 9th

Sec. : D

Wireless Comes of Age

• Guglielmo Marconi invented the wireless telegraph in 1896– Communication by encoding alphanumeric

characters in analog signal

• Communications satellites launched in 1960s

• Advances in wireless technology– Radio, television, mobile telephone,

communication satellites

• More recently– Satellite communications, wireless

networking, cellular technology

Wireless?• A wireless LAN or WLAN is a wireless local

area network that uses radio waves as its carrier.

• The last link with the users is wireless, to give a network connection to all users in a building or campus.

• The backbone network usually uses cables• Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor

• The benefit of wireless networks is driving the explosive growth of the WLAN market.

Broadband Wireless Technology

• Higher data rates obtainable with broadband

wireless technology– Graphics, video, audio

• Shares same advantages of all wireless services: convenience and reduced cost– Service can be deployed faster than fixed

service– No cost of cable plant– Service is mobile, deployed almost anywhere

Limitations and Difficulties of Wireless Technologies

• Wireless is convenient and less expensive

• Limitations and political and

technical difficulties inhibit wireless technologies

• Lack of an industry-wide standard

• Device limitations

• Wireless technologies are currently defined in the following IEEE standards:– 802.11a: Operates at 5.0 GHz and has

a data rate of 54 Mbps– 802.11b: Operates at 2.4 GHz and has

a data rate of 11 Mbps– 802.11g: Operates at 2.4 GHz and has

a data rate of 54 Mbps

The IEEE 802.11 WLAN Standards

Modes of wireless communication

Wireless communication can be via:• Radio frequency communication.

• Microwave communication, for example long-range line-of-sight via highly directional antennas, or short-range communication.

• Infrared (IR) short-range communication, for example from remote controls or via Infrared Data Association (IrDA).

• Applications may involve point-to-point

communication, point-to-multipoint communication, broadcasting, cellular networks and other wireless networks.

Bluetooth Wireless Technology

• Bluetooth is a wireless technology built into electronic gadgets and lets you talk and share information like voice , music and videos wirelessly.• Bluetooth technology was invented in 1994 by Ericsson, a Swedish Company.

• Bluetooth technology also uses radio waves. The biggest difference between Bluetooth technology and devices like radios and TV is distance.• Bluetooth Technology sends information within your personal area space, which is call your Personal Area Network or “Pan” at a distance up to 10m.

Bluetooth Wireless Technology

• Bluetooth technology was originally intended to be a wireless replacement for cables and wires between things like phones , computers , keyboards and mice.• Bluetooth works great in those devices and it can do so much more connecting TV , music players and even home healthcare devices.

• With the rapid advancements in Bluetooth technology , we can now create new connections that we weren’t possible using wires.

Bluetooth Devices

Infrared Wireless Technology

•The light we see with our eyes is really a very small portion of what is called the “ Electromagnetic Spectrum “. The Electromagnetic spectrum includes all types of radiation – from the X-rays used at hospital.•Radiation in Electromagnetic Spectrum is often categorized by wavelength. Short wavelength radiation is of the highest energy and can be very dangerous.•Longer Wavelength radiation is of lower energy and is usually less harmful – examples include radio , microwaves and infrared.

Infrared Wireless Technology

• Although infrared radiation is not visible , humans can sense it – as heat. Infrared means below red , red being the color of the longest wavelengths of visible light.• IR light has a longer wavelength than that of red light , hence below. Infrared imaging is used extensively for military and civilian purposes.• Military applications include surveillance , target acquisition , night vision and tracking. Non-military uses include short-ranged wireless communication , remote temperature sensing and weather forecasting.

Infrared Wireless Technology

Advantages of infrared Wlan

Higher Security Infrared light does not go through walls , so it's nearly impossible for an unauthorized person from outside the physical controlled area of the facility to eavesdrop on the system.

No Radio frequency interference

Because infrared wireless LAN’s operate in the light frequency range , there is no possibility of either inward or outward interference with RF systems.

disadvantages of infrared Wlan

Limited rangeInfrared light doesn't propagate through walls, which demands an access point in each room when providing coverage throughout a facility. This could make the systems more expensive than deploying 802.11 access points that’s each cover several rooms.Proprietary productsOne of the biggest issues with infrared wireless LANs is the lack of conformance with standards. As a result the solutions are proprietary , meaning that the transducers and access points must be the same vendor.

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 Wi-Fi Alliance defines Wi-Fi as any "wireless local area network (WLAN) products that are based on the Institute of Electrical and Electronics Engineers' (IEEE) 802.11 standards".

•However, since most modern WLANs are based on these standards, the term "Wi-Fi" is used in general English as a synonym for "WLAN".

Wi-Fi•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 (65 feet) 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 — this is achieved by using multiple overlapping access points.

Wi-Fi Range•Wi-Fi networks have limited range. A typical wireless access point using 802.11b or 802.11g with a stock antenna might have a range of 32 m (120 ft) indoors and 95 m (300 ft) outdoors. IEEE 802.11n, however, can more than double the range.

•Range also varies with frequency band. Wi-Fi in the 2.4 GHz frequency block has slightly better range than Wi-Fi in the 5 GHz frequency block which is used by 802.11a and optionally by 802.11n.

•On wireless routers with detachable antennas, it is possible to improve range by fitting upgraded antennas which have higher gain in particular directions.

Wi-Fi working

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