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Sunday, July 13, 2008




‘Wireless’—mobile phones, cordless phones, radio equipment , today we use myriad devices that could merit the term however, ‘wireless’ generally means the ability to create a network sans wires. Networking is key to our computing experience, and the Internet is the biggest network of all. What good is a computer if you can’t connect to your Local Area Network or the Internet? Less than one per cent of the computers in the world are standalone machines that lack the ability to connect to others.
Technology advancement has seen the definition of a PC shift from ‘Personal Computer’ to ‘Portable Computer’. The new breeds of laptops are no longer the signature of the higher echelons of management. Today, sales executives and even delivery personnel have mobile devices such as laptops and PDAs to increase efficiency. With technology becoming more and more portable, networking had to catch up, and thus we have wireless networking, which is fast becoming the solution of the future.
Wireless: The Basics
Wireless technology has pervaded our lives—mobile phones, Cordless phones, and infrared remote control devices are just a few examples of the wireless devices we use. This book will steer clear of consumer electronics and mass communication devices , which use infrared, cellular and satellite transmission technologies , and stick to the definition of wireless in Information Technology (IT):“To establish communication without the use of cables or wires , where data distribution occurs through an unguided medium such as the atmosphere, by using radio wave technologies.”
Wireless devices can be used both by businesses and individuals.his book will
Focus on the individual, and address our personal needs and possible deployments of wireless. The most basic use for wireless is to set up a Wireless Local Area Network (WLAN) or Personal Area Network (PAN) at home. This can be achieved by using wireless technologies and protocols such as Wi-Fi and Bluetooth.

What can a wireless network do for me?
A wireless network can let you do the following:-
1.Connect all your devices together without any signs of ugly wires
2.Share files easily between devices
3.Share an Internet connection easily
4.Set up a multiplayer gaming network
5.Carry your mobile devices around your house, the way they were meant to be,
and not worry about losing connectivity to your LAN
6.Show off to your friends, as having a wireless network is the in-thing today
What is Wi-Fi?
A way to get Internet access, the term Wi-Fi is a play upon the decades-old term HiFi that describes the type of output generated by quality musical hardware, Wi-Fi stands for Wireless Fidelity and is used to define any of the wireless technology in the IEEE 802.11 specification - including (but not necessarily limited to) the wireless protocols 802.11a, 802.11b, and 802.11g. The Wi-Fi Alliance is the body responsible for promoting the term and its association with various wireless technology standards.
How Wi-Fi Works ?
Wi-Fi is the wireless way to handle networking. It is also known as 802.11 networking and wireless networking. The big advantage of Wi-Fi is its simplicity. You can connect computers anywhere in your home or office without the need for wires. The computers
Connect to the network using radio signals, and computers can be up to 100 feet or so apart.

Parts of a Wi-Fi Project

Every Wi-Fi project contains specific primary components to make the system work properly .These are broken down into five simple components:
Data signal (Ethernet, computer interface, USB, and so on)
Data to RF converter
Radio transceiver
Transmission line
Antenna system
Developers Of Wi-Fi.

IEEE The Institute of Electrical and Electronics Engineers (IEEE) was formed on January 1, 1963, by way of a merger between the American Institute of Electrical Engineers (AIEE) and the Institute of Radio Engineers (IRE), both leaders in their respective fields. The IEEE publishes 30 per cent of the world’s literature relating to computer science, electrical and electronics engineering. The group has developed almost a thousand industry standards. Visit for more information. For this book, we are only interested in a particular group of the IEEE.
802 IEEE 802 is a collection of networking standards that were designed or researched to run LANs and Metropolitan Area Networks (MANs). They are maintained by a specific committee called the LANMAN Standards Committee (LMSC). This committee oversees the functioning of smaller research groups. It is one of those groups—Group 11 to be precise—that we are getting to.
Group11(802.11) A working group of the LMSC researched and developed the IEEE 802.11 V/LAN standard, which is popularly called Wi-Fi today This family of wireless standards currently includes four major wireless modulation techniques that all run on the same protocol, all developed by the IEEE 802.11 group. The standards are 802.lla, 802.llb, 802.llg, and 802.lln. The very first wireless standard was released in 1997, and was simply termed 802.11. It offered theoretical speeds of 1 Mbps and 2 Mbps, and operated at the 2.4 GHz

1. Adding Wi-Fi to a Computer :-
One of the best things about Wi-Fi is how simple it is. Many new laptops already come with a Wi-Fi card built in -- in many cases you don't have to do anything to start using Wi-Fi. It is also easy to add a Wi-Fi card to an older laptop or a desktop PC. Here's what you do:
Buy a 802.11a, 802.11b or 802.11g network card. 802.11g has the advantage of higher speeds and good interoperability on 802.11b equipment.
Network adapters with the Wi-Fi
For a laptop, this card will normally be a PCMCIA card that you slide into a PCMCIA slot on your laptop. Or you can buy a small external adapter and plug it into a USB port.
For a desktop machine, you can buy a PCI card that you install inside the machine, or a small external adapter that you connect to the computer with a USB cable Install the card
Install the drivers for the card
Find an 802.11 hotspot
Access the hotspot.
A hotspot is a connection point for a Wi-Fi network. It is a small box that is hardwired into the Internet. The box contains an 802.11 radio that can simultaneously talk to up to 100 or so 802.11 cards. There are many Wi-Fi hotspots now available in public places like restaurants, hotels, libraries and airports.
2. Configuring Wi-Fi :-
On the newest machines, an 802.11 card will automatically connect with an 802.11 hotspot and a network connection will be established. As soon as you turn on your machine, it will connect and you will be able to browse the Web, send email, etc. using Wi-Fi. On older machines you often have to go through this simple 3-step process to connect to a hotspot:
Access the software for the 802.11 card -- normally there is an icon for the card down in the system tray at the bottom right of the screen.
Click the "Search button" in the software. The card will search for all of the available hotspots in the area and show you a list.
Double-click on one of the hotspots to connect to it.
On ancient 802.11 equipment, there is no automatic search feature. You have to find what is known as the SSID of the hotspot (usually a short word of 10 characters or less) as well as the channel number (an integer between 1 and 11) and type these two pieces of information in manually. All the search feature is doing is grabbing these two pieces of information from the radio signals generated by the hotspot and displaying them for you
Wi-Fi's Radio Technology
The radios used in Wi-Fi are not so different from the radios used in $5 walkie-talkies. They have the ability to transmit and receive. They have the ability to convert 1s and 0s into radio waves and then back into 1s and 0s. There are three big differences between Wi-Fi radios and Walkie-talkies:
Wi-Fi radios that work with the 802.11b and 802.11g standards transmit at 2.4 GHz, while those that comply with the 802.11a standard transmit at 5 GHz. Normal walkie-talkies normally operate at 49 MHz. The higher frequency allows higher data rates.
Wi-Fi radios use much more efficient coding techniques that also contribute to the much higher data rates. For 802.11a and 802.11g, the technique is known as orthogonal frequency-division multiplexing (OFDM). For 802.11b, it is called Complementary Code Keying (CCK). See this page for details.
The radios used for Wi-Fi have the ability to change frequencies. 802.11b cards can transmit directly on any of three bands, or they can split the available radio bandwidth into dozens of channels and frequency hop rapidly between them. The advantage of frequency hopping is that it is much more immune to interference and can allow dozens of Wi-Fi cards to talk simultaneously without interfering with each other.
Because they are transmitting at much higher frequencies than a Walkie-Talkie, and because of the encoding techniques, Wi-Fi radios can handle a lot more data per second. 802.11b can handle up to 11 megabits per second (although 7 megabits per second is more typical, and 802.11b may fall back as low as 1 or 2 megabits per second if there is a lot of interference). 802.11a and 802.11g can handle up to 54 megabits per second (although 30 megabits per second is more typical).
You might be wondering where the funny 802.11 nomenclature comes from. The Institute of Electrical and Electronics Engineers (IEEE) creates standards, and they number these standards in unique ways. The 802.11 standard covers wireless networks. The a, b and g notations identify different flavors of the 802.11 standard:
802.11b was the first version to reach the marketplace. It is the slowest and least expensive of the three. As mentioned above, 802.11b transmits at 2.4 GHz and can handle up to 11 megabits per second.
802.11a was next. It operates at 5 GHz and can handle up to 54 megabits per second.
802.11g is a mix of both worlds. It operates at 2.4Ghz (giving it the cost advantage of 802.11b) but it has the 54 megabits per second speed of 802.11a.
Fortunately, all of this radio technology is hidden in a Wi-Fi card and is completely invisible. Wi-Fi, in fact, is one of the easiest technologies that you will ever use

Wi-Fi Security
Wi-Fi hotspots can be open or secure. If a hotspot is open, then anyone with a Wi-Fi card can access the hotspot. If it is secure, then the user needs to know a WEP key to connect.
WEP stands for Wired Equivalent Privacy, and it is an encryption system for the data that 802.11 sends through the air. WEP has two variations: 64-bit encryption (really 40-bit) and 128-bit encryption (really 104-bit). 40-bit encryption was the original standard but was found to be easily broken (see this page for an explanation). 128-bit encryption is more secure and is what most people use if they enable WEP.
For a casual user, any hotspot that is using WEP is inaccessible unless you know the WEP key.
If you are setting up a hotspot in your home, you may want to create and use a 128-bit WEP key to prevent the neighbors from casually eavesdropping on your network.
Whether at home or on the road, you need to know the WEP key, and then enter it into the Wi-Fi card's software, to gain access to the network.
Just over a year ago, surveys revealed that most public and private Wi-Fi networks used no encryption at all, meaning that anyone with a laptop and Wi-Fi card could intercept and read data packets being sent or received by legitimate users. This could happen even without actually connecting to the wireless router. All that is needed is the ability to "sniff" the airwaves, a rudimentary function offered by dozens of easily downloadable utilities, such as those used by "wardrivers." (Wardrivers are those who wander the streets with Wi-Fi gear looking for networks to join -- most are hobbyists or simple bandwidth seekers, but some are malicious).

Is Wi-Fi the same as Bluetooth?
No. While both are wireless technology terms, Bluetooth technology lives under the IEEE protocol 802.15.1, while Wi-Fi falls under the 802.11 specification. What this means for consumers is that appliances using Wi-Fi technology and those using Bluetooth technology are not interoperable. Bluetooth and Wi-Fi are different in several ways, and are not necessarily in competition. Wi-Fi technology boasts faster data transfer speeds and range, making it a good replacement for Ethernet (802.3) systems, while Bluetooth requires less power and is therefore more prominent in small appliances, such as PDAs
What is a Wi-Fi Hotspot?
A Wi-Fi hotspot is defined as any location in which 802.11 (wireless) technology both exists and is available for use to consumers. In some cases the wireless access is free, and in others, wireless carriers charge for Wi-Fi usage. Generally, the most common usage of Wi-Fi technology is for laptop users to gain Internet access in locations such as airports, coffee shops, and so on, where Wi-Fi technology can be used to help consumers in their pursuit of work-based or recreational Internet usage.
Uses Of The Wi-Fi Technologies
Wi-Fi Hardware Accessories

Linksys WPC54G Wireless-G Notebook Adapter

Linksys WUSB11 Wireless-B USB Network Adapter

D-Link DBT-120 Bluetooth USB Adapter, PC/Mac

Linksys WRT54GX Wireless-G Broadband Router with SRX

Linksys WUSB54G Wireless-G USB Adapter

Linksys WRT54G Wireless-G Router

Netgear WGR614 802.11g Wireless Router

Linksys Compact Wireless-G Broadband Router WRT54GC

Linksys WRT54GS Wireless-G Broadband Router with SpeedBooster

Apple AirPort Express with Air Tunes (M9470LL/A)

Wi-Fi Connect all your devices together without any signs of ugly wires .It also Share files easily between devices, share an Internet connection easily, Set up a multiplayer gaming network, Carry your mobile devices around your house, the way they were meant to be, and not worry about losing connectivity to your LAN, show off to your friends, as having a wireless network is the in-thing today

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