The basics of wireless networking
Currently, there are four wireless-networking standards competing for your airtime. 802.11b is the corporate darling and has a suitably wide range for use in big office spaces. 802.11a offers bigger bandwidth and fewer interference problems but a shorter range. Bluetooth is meant for short-range, temporary networking in conference rooms, schools, or homes. The most recent addition to the wireless throng is 802.11g, which became an official standard in June 2003. 802.11g combines the long range of 802.11b and the high throughput of 802.11a. It is also fully compatible with older 802.11b equipment. Check out our side-by-side comparison of these different technologies.
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802.11b reigns supreme
802.11b is currently the most popular and least expensive wireless LAN specification. It operates in the 2.4GHz radio spectrum and can transmit data at speeds up to 11Mbps within a 100-foot range. Its balance of economy, bandwidth, and particularly range have made it the dominant standard for business, and many employees have taken the technology home with them for work and family computing. The Wireless Ethernet Compatibility Alliance (WECA) has done its part by certifying hundreds of products to make sure they work together. But Wi-Fi has a couple of drawbacks. It shares airspace with cell phones, Bluetooth, security radios, and other devices, so it's vulnerable to interference. And because of data-transfer overhead and the inevitable wall or other transmission obstacle, its real throughput is closer to 5Mbps, or about half of its spec.
802.11a: are its days numbered?
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Because 802.11b and 802.11a use different bands within the radio spectrum, they are incompatible with one another. However, dual-band equipment is currently available, which makes it possible to connect at both 2.4GHz and 5GHz, but prepare to pay twice the price for this gear. If you want to make a choice between the two bands and stick to it, consider these factors: If you already use one or the other standard at your business, you should probably use the same at home to make telecommuting easier. If compatibility and price are not issues, 802.11a's better performance and lower susceptibility to interference could be worth the extra expense. But if you need to cover a lot of ground cheaply, 802.11b's the more efficient choice.
Move over Wi-Fi, 802.11g is here
802.11g, long touted as the high-performance successor of 802.11b, was ratified in June 2003, but networking manufacturers flooded the market with 802.11g gear months before it was approved as a standard. Most of of the gear that was sold prior to ratification will need a firmware upgrade to bring it up to the final spec. 802.11g has two features that many believe will make it the new dominant Wi-Fi standard: great throughput at around 22Mbps and backward compatibility with 802.11b. ThatÂ's right; 802.11g operates at the same frequency as 802.11b (2.4GHz) and is backward compatible with the granddaddy of Wi-Fi specs. This makes 802.11g the obvious choice not only for anyone building a new network, but also for those interested in adding onto or gradually upgrading a preexisting 802.11b network. The only downside to 802.11g is the fact that it uses a more crowded slice of spectrum with only three nonoverlapping channels. This will make 802.11a a better choice for some environments, especially those populated with devices that share the 2.4GHz spectrum, such as cordless phones, baby monitors, microwave ovens, and Bluetooth radios.
Bluetooth takes small bites, chews slowly
Named for a tenth-century Danish king, Bluetooth is a somewhat different standard from the 802.11 suite of specs, offering much more flexibility but on a smaller, "personal area network" scale called a PAN. Its actual throughput is a poky 500Kbps, and its range is just a couple dozen feet. But unlike the 802.11 wireless-LAN-oriented standards, which typically run through centralized access points, all devices with a Bluetooth radio and antennae can speak to each other with little or no preparation in a more peer-to-peer fashion. It's also poised to replace infrared ports as the instant-transfer mode of choice, with better range and no line-of-sight requirement. Meeting attendees can immediately transfer files across a conference table between Bluetooth-equipped notebooks, or they can send a file to a Bluetooth-equipped printer without downloading drivers. Bluetooth-equipped kiosks in airports and coffeehouses let you log on to the Internet through your laptop or PDA. Bluetooth will soon be standard equipment on many cell phones and handheld computers. There's even talk of putting Bluetooth into home appliances. But for all the theoretical benefits of Bluetooth, the reality is that it's currently a mess of incompatible hardware and software. And because Bluetooth, 802.11b, and 802.11g all occupy the same frequency range, they can eat into each other's bandwidth and reduce throughput and even disrupt data transmissions.
In the next section, we'll look at how to set up a wireless LAN, what equipment you'll need, and how much it will cost.
| • | The basics of wireless networking | • | Sweating the details |
| • | The lay of the LAN | • | Optimizing and securing your network |
