Wireless Fidelity – popularly known as Wi-Fi, developed on IEEE 802.11 standards, is the recent technology advancement in wireless communication. As the name indicates, WI-FI provides wireless access to applications and data across a radio network. WI-FI sets up numerous ways to build up a connection between the transmitter and the receiver such as DSSS, FHSS, IR – Infrared and OFDM. The development on WI-FI technology began in 1997 when the Institute of Electrical and Electronic Engineers (IEEE) introduced the 802.11 technology that carried higher capacities of data across the network. This greatly interested some of major brands across the globe such as the world famous Cisco Systems or 3COM. Initially, the price of Wi-Fi was very high but around in 2002, the IT market witnessed the arrival of a break through product that worked under the new 802.11 g standards. In 2003, IEEE sanctioned the standard and the world saw the creation of affordable Wi-Fi for the masses.
Wi-Fi provides its users with the liberty of connecting to the Internet from any place such as their home, office or a public place without the hassles of plugging in the wires. Wi-Fi is quicker than the conventional modem for accessing information over a large network. With the help of different amplifiers, the users can easily change their location without disruption in their network access. Wi-Fi devices are compliant with each other to grant efficient access of information to the user. Wi-Fi location where the users can connect to the wireless network is called a Wi-Fi hotspot. Through the Wi-Fi hotspot, the users can even enhance their home business as accessing information through Wi-Fi is simple. Accessing a wireless network through a hotspot in some cases is cost-free while in some it may carry additional charges. Many standard Wi-Fi devices such as PCI, miniPCI, USB, Cardbus and PC card, ExpressCard make the Wi-Fi experience convenient and pleasurable for the users. Distance from a wireless network can lessen the signal strength to quite an extent; some devices such as Ermanno Pietrosemoli and EsLaRed of Venezuela Distance are used for amplifying the signal strength of the network. These devices create an embedded system that corresponds with any other node on the Internet.
Wi-Fi provides its users with the liberty of connecting to the Internet from any place such as their home, office or a public place without the hassles of plugging in the wires. Wi-Fi is quicker than the conventional modem for accessing information over a large network. With the help of different amplifiers, the users can easily change their location without disruption in their network access. Wi-Fi devices are compliant with each other to grant efficient access of information to the user. Wi-Fi location where the users can connect to the wireless network is called a Wi-Fi hotspot. Through the Wi-Fi hotspot, the users can even enhance their home business as accessing information through Wi-Fi is simple. Accessing a wireless network through a hotspot in some cases is cost-free while in some it may carry additional charges. Many standard Wi-Fi devices such as PCI, miniPCI, USB, Cardbus and PC card, ExpressCard make the Wi-Fi experience convenient and pleasurable for the users. Distance from a wireless network can lessen the signal strength to quite an extent; some devices such as Ermanno Pietrosemoli and EsLaRed of Venezuela Distance are used for amplifying the signal strength of the network. These devices create an embedded system that corresponds with any other node on the Internet.
The market is flooded with various Wi-Fi software tools. Each of these tools is specifically designed for different types of networks, operating systems and usage type. For accessing multiple network platforms, Aircrack-ng is by far the best amongst its counterparts. The preferred Wi-Fi software tools list for Windows users is: KNSGEM II, NetStumbler, OmniPeek, Stumbverter, WiFi Hopper, APTools. Unix users should pick any of the following: Aircrack, Aircrack-ptw, AirSnort, CoWPAtty,Karma . Whereas, Mac users are presented with these options: MacStumble, KisMAC, Kismet. It is imperative for users to pick out a Wi-Fi software tool that is compatible with their computer and its dynamics.
Wi-Fi uses radio networks to transmit data between its users. Such networks are made up of cells that provide coverage across the network. The more the number of cells, the greater and stronger is the coverage on the radio network. The radio technology is a complete package deal as it offers a safe and consistent connectivity. Radio bands such as 2.4GHz and 5GHz depend on wireless hardware such Ethernet protocol and CSMA. Initially, Phase Shift Keying (PSK), a modulation method for conveying data was used, however now it has been replaced with CCK. Wi-Fi uses many spectrums such as FHSS and DSSS. The most popular Wi-Fi technology such as 802.11b operates on the range of 2.40 GHz up to 2.4835 GHz band. This provides a comprehensive platform for operating Bluetooth strategy, cellular phones, and other scientific equipments. While 802.11a technology has the range of 5.725 GHz to 5.850 GHz and provides up to 54 Mbps in speed. 802.11g technology is even better as it covers three non-overlapping channels and allows PBCC. 802.11e technology takes a fair lead by providing excellent streaming quality of video, audio, voice channels etc.
Wireless Standards:
The official name for the specification is IEEE 802.11, and it is comprised of more than 20 different standards, each of which is denoted by a letter appended to the end of the name. The most familiar standards are 802.11b and 802.11g (Wireless B and G) which are used in the majority of commercial Wi-Fi devices. Both of these standards operate in the 2.4 GHz band, and the only major difference between the two is the transfer rate.
Some consumer electronics, however, use a different standard—Wireless A. These devices operate within the 5 GHz range and have transfer rates equivalent to 802.11g. However, since they operate on different frequencies, devices using the 802.11a standard cannot communicate with B and G-enabled devices. For this reason, it is important to check the compatibility of components with your wireless network prior to purchasing them.
Comparison of standards:
The table below provides a brief overview of the three most popular current 802.11 standards, as well as information about the next version of Wi-Fi — 802.11n.
Advantages of Wi-Fi
Now that we've covered the basics of the technology, let's check out some of the advantages Wi-Fi has over its wireless (and wired) competition.
Unparalleled mobility and flexibility:Now that we've covered the basics of the technology, let's check out some of the advantages Wi-Fi has over its wireless (and wired) competition.
If you've ever installed a multi-room stereo and had to run wires through a wall, you know the amount of time and effort it requires, not to mention the permanence of your installation. If you want to move the receiver to another room, the wiring has to be completely redone, and the holes patched.
Thanks to Wi-Fi, users are no longer confined by the cords that link their devices, enabling new levels of connectivity without sacrificing function or design options. Many new products, called music streamers, are being introduced that utilize Wi-Fi technology to wirelessly broadcast your music to speakers located throughout your house. Some systems are different than others, but typically you can listen to the same, or different music in each room, play music from the server or any computer attached to the network, and even listen to internet radio.
Quick, easy setup
Setting up a wireless network may sound like a daunting task, but it's actually a pretty straightforward process. Wi-Fi networks don't require professional installation, and, best of all, there are no holes to drill or wires to run through walls. Many new routers are "plug-and-play," meaning you just connect them to a power outlet, plug in an Ethernet cord, your network has been created. Unfortunately, wireless security doesn't automatically configure itself, so it's important to remember to enable it via a personal computer once a connection to the wireless network has been established.
Fast data transfer rates:
With transfer speeds up to 54 megabits (Mb) per second (6.75 megabytes), 802.11g is currently the fastest commercially available Wi-Fi protocol on the market. It is important to note that this is the maximum theoretical transfer rate, not that which one should expect on a daily basis. Nonetheless, typical 802.11g networks are more than capable of handling the demands of streaming standard-definition TV signals, as well as CD-quality audio.
Limitations of Wi-Fi:
Security and interference are the main issues with current Wi-Fi standards, as well as its inability to reliably stream high definition audio and video.
Security concerns:
Though typically very easy to set up, securing your Wi-Fi network requires more effort. Wi-Fi access points do not come with encryption straight out of the box; you have to do it from your computer once the network is up and running. An unsecured wireless network is susceptible to attacks from hackers, potentially giving them access to all of the information stored by the devices on your network. In addition, "friendly," yet unauthorized computers will also be able to connect to your network, occupying the bandwidth and hindering overall network performance.
Interference from other devices:
Wi-Fi transmissions take place primarily within the 2.4 GHz spectrum, making them susceptible to interference from Bluetooth® wireless enabled devices, cordless telephones, microwave ovens, baby monitors, and other household devices. The farther your Wi-Fi devices are located from these known interferers—and the closer they are to one another—the more robust your signal will be, so keep that in mind during setup.
If you live in an apartment complex or in close proximity to your neighbors, their wireless network can also be a source of interference. However, many newer routers automatically select the channel with the least amount of interference, ensuring that you get the best possible connection.
Lack of support for high-quality media streaming:
Even the fastest current Wi-Fi standards are pushed beyond their limit when trying to handle some of today's high-end media. High-definition audio and video files are bandwidth and timely-delivery-intensive, and typical wireless networks have neither the transfer speeds nor the consistency to transfer them flawlessly. This problem is further compounded if there are multiple devices connected to the same access point because the bandwidth must be divided between all of the equipment.
Securing your Wi-Fi network
The best choice for wireless network encryption is currently Wi-Fi Protected Access (WPA2). Most newer access points support WPA2 encryption, and it can be configured once your network has been set up. For more security tips, check out our article on creating a home network.
Bluetooth® wireless technology, on the other hand, has security built in, and it automatically requires devices to enter a passkey in order to connect to the network.
Wi-Fi's Future: 802.11n
When completed (currently scheduled for late 2009), wireless specification 802.11n should open the door to a vast assortment of new applications. Though the final specifications have not been determined, transfer speeds are reportedly 10 times faster than current standards (540 Mbps as opposed to 802.11g's 54 Mbps). That's more than enough bandwidth to support even the most demanding transfers, enabling users to stream high-definition audio and video, play games, and surf the internet with no delays or quality loss.
Pre-N products
Unable to wait for the 802.11n standard to be finalized, some manufacturers have released "pre-N" routers and wireless cards. With 600% speed increases over 802.11g, they are capable of handling streaming HDTV signals and audiophile-grade audio. In addition, pre-N routers reportedly offer an 800% increase in wireless network coverage, adding both range and stability. For home theater enthusiasts who have to have the newest technology, pre-N routers offer a glimpse of the future, and they're pretty reasonably priced, with both routers and wireless cards in the $100 neighborhood.
Interoperability remains a question mark for pre-N products, since no official standard has been approved, but manufacturers claim their products not only have no problems communicating with devices using other standards, they actually increase their performance as well. Whether or not the pre-N devices will be compliant with the 802.11n standard when it is released is still unknown, and we probably won't know for sure until the first 802.11n products begin rolling off the shelves in late 2009.
High-quality media streaming finally a reality
The main advantage of 802.11n is the interconnectedness it creates between components on the same network. Internet speeds are restricted by numerous factors (including the speed of the access point, the quality of the internet connection, and the memory on your computer). While the step from G to N will not typically lead to drastic improvement in internet download speeds, internal data transfer rates are not restricted by the same factors, allowing the full potential of the technology to be realized. Since 802.11n devices are ten times faster than current standards, devices will be able to transfer ten times the information in the same amount of time. If the standard is approved, and transfer rates remain at their speculated levels, reliable, high-definition streaming media may finally become a reality.
The ability to transfer data internally, between the devices on your personal network, is where 802.11n differentiates itself from previous standards. It will be interesting to see the creative new products that are made possible by the certification of the new standard.
