WIRELESS NETWORKING
Introduction
A wireless network is any type of computer network that uses wireless data connections for connecting network nodes .Wireless networking is a method by which homes, telecommunications networks and enterprise (business).Installations avoid the costly process of introducing cables into a building, or as a connection between various equipment locations. Wireless telecommunications networks are generally implemented and administered using radio communication. This implementation takes place at the physical level (layer) of the OSI model network structure.
Examples of wireless networks include cell phone networks, Wi-Fi local networks and terrestrial microwave networks.
Wireless network made up of
There are two kinds of wireless networks: * An ad-hoc, or peer-to-peer wireless network * Access point

Ad-hoc or peer-to-peer wireless network
It consists of a number of computers each equipped with a wireless networking interface card. Each computer can communicate directly with all of the other wireless enabled computers. They can share files and printers this way, but may not be able to access wired LAN resources, unless one of the computers acts as a bridge to the wired LAN using special software. (This is called "bridging")

Each computer with a wireless interface can communicate directly with all of the others.

Access point or base station
A wireless network can also use an access point, or base station. In this type of network the access point acts like a hub, providing connectivity for the wireless computers. It can connect (or "bridge") the wireless LAN to a wired LAN, allowing wireless computer access to LAN resources, such as file servers or existing Internet Connectivity.

There are two types of access points: * Hardware access points (HAP) * Software Access Points

Hardware access points (HAP)
Dedicated hardware access points (HAP) such as Lucent's Wave LAN, Apple's Airport Base Station or Web Gear's Aviator PRO (See Figure 2). Hardware access points offer comprehensive support of most wireless features, but check your requirements carefully. Wireless connected computers using a Hardware Access Point.

Software Access Points
Software Access Points which run on a computer equipped with a wireless network interface card as used in an ad-hoc or peer-to-peer wireless network. (See Figure 1) The Vicomsoft Inter Gate suites are software routers that can be used as a basic Software Access Point, and include features not commonly found in hardware solutions, such as Direct PPPoE support and extensive configuration flexibility, but may not offer the full range of wireless features defined in the 802.11 standard.
With appropriate networking software support, users on the wireless LAN can share files and printers located on the wired LAN and vice versa. Vicomsoft's solutions support file sharing using TCP/IP. Wireless connected computers using a Software Access Point.

How can I use a wireless network to share an Internet connection?
Once you realize that wireless cards are analogous to Ethernet cards and that empty space is analogous to Ethernet cabling, the answer to this question becomes clear. To share an Internet connection across a LAN you need two things:
• An Internet sharing hardware device or software program
• A LAN
If your LAN is wireless, the same criteria apply. You need hardware or software access point and a wireless LAN. Any computer equipped with a wireless network card running suitable Internet sharing software can be used as a software access point. A number of vendors offer hardware access points.
A hardware access point may provide Internet Sharing capabilities to Wired LAN computers, but does not usually provide much flexibility beyond very simple configurations.

Software Access Point with Internet
Wireless connected computers using a Software Access Point for shared Internet access.

Hardware Access Point with Internet
Wireless connected computers using a Hardware Access Point for shared Internet access.

If I have more than one hardware access point, how can I share a single Internet connection?
If an existing wired LAN already has an Internet connection, then the hardware access points simply connect to your LAN and allow wireless computers to access the existing Internet connection in the same way as wired LAN computers.

IEEE 802.11:-
Wireless networking hardware requires the use of underlying technology that deals with radio frequencies as well as data transmission. The most widely used standard is 802.11 produced by the Institute of Electrical and Electronic Engineers (IEEE). This is a standard defining all aspects of Radio Frequency Wireless networking
Roaming:-
A wireless computer can "roam" from one access point to another, with the software and hardware maintaining a steady network connection by monitoring the signal strength from in-range access points and locking on to the one with the best quality. Usually this is completely transparent to the user; they are not aware that a different access point is being used from area to area. Some access point configurations require security authentication when swapping access points, usually in the form of a password dialog box.
Access points are required to have overlapping wireless areas to achieve this as can be seen in the following diagram:
A user can move from Area 1 to Area 2 transparently. The Wireless networking hardware automatically swaps to the Access Point with the best signal.

Not all access points are capable of being configured to support roaming. Also of note is that any access points for a single vendor should be used when implementing roaming, as there is no official standard for this feature.

ADVANTAGES OF WI-FI:

You get greater mobility: Since you're unthread you can move around with your laptop, and as long as you stay within range of your access point, you won't lose your connection. (You can usually rove about 75 to 150 feet from the access point if you're indoors; farther if you're outdoors.) So, go ahead and send e-mail while you lounge on the deck, or surf the web from the kitchen.
You get quick, easy installation: There are no wires to fish through walls or run along baseboards, so you won't need to drill holes in your floors or drywall. Because of this, a Wi-Fi network can be set up in a matter of minutes (not including the time it takes to configure the security measures. It's fairly fast For providing such serious gains in convenience and ease of installation, Wi-Fi doesn't require a significant tradeoff in speed. The version of Wi-Fi most recently implemented for the majority of consumer electronics and home computers — known to engineers as IEEE 802.11g — transfers data in the 2.4GHz frequency band, at speeds up to 54 Megabits per second. That's almost five times faster than the previous version, and faster than a wired Ethernet network (10Base-T). Plus, the current standard is backwards-compatible with the previous one (the still-popular 802.11b), so if you already own older gear, your brand-new Wi-Fi hardware will work with it to deliver up to 11Mbps data transfer (the maximum speed of the 11b standard).

Disadvantages of Wi-FI
• The 802.11b and 802.11g flavors of Wi-Fi use the 2.4 GHz spectrum, which is crowded with other devices such as Bluetooth, microwave ovens, cordless phones, or video sender devices, among many others. This may cause degradation in performance. Other devices which use microwave frequencies such as certain types of cell phones can also cause degradation in performance.
• Power consumption is fairly high compared to other standards, making battery life and heat a concern.
• Not always configured properly by user. Commonly uses WEP (Wired Equivalent Privacy) protocol for protection, though has been shown to be easily breakable. Newer wireless solutions are slowly providing support for the superior WPA (Wi-Fi Protected Access) protocol, though many systems still employ WEP.

CONCLUSION
Today, Wi-Fi is mainly used for making easy connections between a home computer and the Internet. But soon, we'll see even friendlier and easier solutions for all kinds of wireless transmissions — including streaming of music and video. This article is just a first step toward understanding Wi-Fi. Keep an eye on the Advisor as we continue to keep you up-to-date on this hot technology!