Thursday, September 18, 2008

What is Wi-Fi?

Wireless fidelity, WI-FI, was created by an organization called the Wi-Fi Alliance which supervises tests that certify product interoperability. A product that passes the alliance tests is given the label "Wi-Fi certified" (a registered trademark). It is sometimes spelled WiFi, Wi-fi, Wifi, or wifi.

Wi-Fi is an established world-wide networking standard which incorporates the use of radio waves to link computers and other network devices together. This limited-range wireless networking protocol uses the 802.11 standard, which was developed by the Institute of Electrical and Electronics Engineers (IEEE) and released in 1997. The 802.11 standard is often called wireless Ethernet since it is intended to replace networking cable.

Wi-Fi has gained acceptance in many businesses, agencies, schools, and homes as an alternative to a wired LAN. Many airports, hotels, and fast-food facilities offer public access to Wi-Fi networks. These locations are known as hot spots.

How does Wi-Fi work?

Like cell phones and radios, wireless networks use radio waves. These radio waves use 802.11 networking standards, which encompass several protocols.In fact, communication across a wireless network is a lot like a two-way radio communication. 1-The router receives the information from the Internet, translates it into a radio signal and sends it to the computer via a wireless adapter. 2-A computer's wireless adapter translates data into a radio signal and transmits it using an antenna.The wireless router receives the signal and decodes it.It sends the information to the Internet using a wired Ethernet connection.

Popular Wi-Fi devices currently on the market
(see all the Wi-Fi products available at the Wired for Wireless store)

Wireless Access Points: wireless switchboards that connect wireless devices on the network.
Wireless Routers: A router is a device that connects a local area network to the Internet. Wireless Routers are actually wired routers with built-in wireless access points. They will wirelessly connect other wireless devices to the network and therefore to the Internet.
Wireless Network Adapters: connect a computer to the network. The two most common are the PC cards and the USB adapters.
Wireless Range Extenders: also known as repeaters, increase the wireless network coverage.
Wireless Bridges: connect a wireless network segment to a wired network segment (Ethernet adapter)
Note: most of the access points on the market operate as repeater/bridge mode.
Wireless Network Storage:creates access to USB storage devices (USB hard drives or flash drives) that are then available for everyone on the network.
Wireless Printer Servers: provide USB ports, allowing any computer on the network to connect to one or several printers.
Network Cameras (IP Cameras): Stream live video to your home, office, vacation home, or anywhere else through the Internet.
Voice Over IP(VoIP): technology that allows someone to place voice telephone calls over the internet. There are several major companies like Vonage and Skype that now offer VoIP services.
Wi-Fi Internet Radios: Listen live to thousands of Internet radio stations from around the globe without a subscription!
Wireless Media Players: stream music, photos and videos from your PC to your TV and stereo system.
Power over Ethernet(PoE): enables electrical power to be sent to a device (an Access Point for instance) over an Ethernet networking. No electrical outlet needed!

The 802.11 family

- 802.11b
In July 1999, IEEE expanded on the original 802.11 standard (which is no longer manufactured), creating the 802.11b specification. 802.11b supports bandwidth up to 11 Mbps (on the 2.4GHz spectrum), comparable to traditional Ethernet. 802.11b is the old protocol. Most vendors no longer sell it.
- 802.11a
802.11a was created at the same time as 802.11b. 802.11a supports bandwidths up to 54 Mbps, much like a growing number of cordless phones, and signals in a regulated frequency spectrum around 5 GHz, preventing signal interference from other devices. This higher frequency compared to 802.11b shortens the range of 802.11a networks. Because 802.11a and 802.11b utilize different frequencies, the two technologies are incompatible with each other.
- 802.11g
In 2002 and 2003, WLAN products supporting a newer standard called 802.11g emerged on the market. 802.11g attempts to combine the bestof both 802.11a and 802.11b. 802.11g supports bandwidth up to 54 Mbps, and for greater range uses the 2.4 GHz frequency (appliances may interfere on the signal frequency). 802.11g is backwards compatible with 802.11b, meaning that 802.11g access points will work with 802.11b wireless network adapters and vice versa. 802.11g has become the new standard for Wi-Fi networking.
Note: Faster variants of 802.11g are available: super G, MIMO, pre-N.However, because these products are based on proprietary solutions, not a ratified standard, mixing and matching gear across vendors typically results in degraded performance.
- 802.11n
The newest IEEE standard in the Wi-Fi category is 802.11n. It was designed to improve the amount of bandwidth supported by utilizing multiple wireless signals and antennas (called MIMO technology) instead of one.
802.11n is a breakthrough technology that enables Wi-Fi networks to do more, faster, and over a larger area. 802.11n Wi-Fi provides the very best connection available for computer networking and home entertainment applications alike - delivering the range, bandwidth, and performance today's multimedia applications and products demand.
The new industry certification for 802.11n is called Wi-Fi certified 802.11n draft 2.0 and is the consumer's indication that a product has passed rigorous testing and can deliver the very best user experience.
The certification tests products based on a draft of the IEEE 802.11n standard ("draft 2.0"), and the program will be updated when that standard is fully ratified by IEEE, expected in late 2008 or early 2009.
Because the industry has been very eager to bring advanced Wi-Fi technology to market, there are numerous "pre-n" products currently available. However, consumers should be aware that only Wi-Fi certified 802.11n draft 2.0 products have been tested for interoperability, standards-based security protections, and backward compatibility with 802.11a, b, and g networks.
Note: If you want to set up a wireless network our advice is to buy Wi-Fi certified 802.11n draft 2.0 products, or other ‘pre-N’ or non certified N products as long as all the devices come from the same manufacturer.

Wi-Fi versus Bluetooth

Wi-Fi and Bluetooth are the most dominant technologies in today's wireless home networks. They are not competition but actually design to coexist in the network since these technologies respectively replace peripheral cables and networking cable (Ethernet).

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