Wireless is in the cards

D-Link Systems' DWL-650H uses 64-bit and 128-bit WEP encryption, works with Windows and is priced at $99.

Linksys Group's WPC11 3.0 works with Windows systems and uses both 64-bit and 128-bit WEP. It's priced at $100.

The Orinoco PC CardGold uses 128-bit RC4 encryption and has drivers for many operating systems. It's priced at $119.

Wi-Fi NICs and access points put your LAN on the air

If you want to move about your workplace freely but still need to download e-mail, send messages or grab files from a network server without dragging a stream of cables behind your notebook PC, here's some good news: Wireless networking has come of age.

Devices that meet the IEEE 802.11b wireless standard, commonly called Wi-Fi, are mature, reasonably priced and reliable. It's easy to configure and install, and millions of home and office users are successfully working wireless.

Simply put, a wireless LAN lets remote computers communicate with traditional Ethernet LANs using radio waves instead of cables. The main components of most WLANs are access points and wireless network interface cards.

Access points are the links to the wired LAN. They contain transmitters and receivers for sending and receiving radio signals to and from remote desktop or notebook PCs. Wireless network interface cards (NICs) such as those listed in the accompanying chart have tiny antennas for picking up and returning signals to the access point and are installed in the remote computers.

There are two types of 802.11b wireless configurations. The first, called the infrastructure mode, requires that an access point be used for connecting remote users to a traditional wired LAN. The wireless connection is invisible to users; they can perform all their tasks as if they were physically linked to the LAN.

The second type, an ad hoc wireless configuration, allows peer-to-peer connections among notebooks containing wireless PC Cards, such as the 802.11b NICs listed in the chart. Users of this system have the freedom to roam about at will while communicating to each other, but they are not connected to a wired LAN.

$100 per NIC
Wi-Fi has become the de facto standard for WLAN communications to date. Prices have dropped dramatically since Wi-Fi equipment first arrived on dealers' shelves in 1999. The cost of a typical Wi-Fi NIC is around $100, and many Wi-Fi access points can now be purchased for less than $200.

The prices, coupled with improved performance, have boosted Wi-Fi equipment sales. More than 20 million 802.11b Wi-Fi LAN access points and NICs will be sold this year, a figure that will rise to about 30 million by 2004, according to industry analysts.

Wi-Fi devices are generally interoperable, but most Wi-Fi LAN manufacturers advise that you use their 'native' NICs with their own access points.

If you have concerns about interoperability'and you should'check to see if the Wi-Fi NIC you're buying has been given the Wireless Ethernet Compatibility Alliance's (WECA) Wi-Fi seal of approval. WECA, at www.wi-fi.com, is an industry consortium that tests for 802.11b interoperability.

All Wi-Fi products run on the 2.4-GHz radio frequency and are rated at an 11-Mbps throughput. But in practice expect a maximum of between 4 and 6 Mbps throughput; signal control and network protocol information takes up the remaining usable bandwidth.

The distance you can roam with a notebook equipped with a Wi-Fi NIC depends largely on the environment of your WLAN. In an unobstructed area, you can expect a range of 200 feet to 500 feet from your access point, with 300 feet being typical. But if you are using the system in an office with multiple dividing walls, hallways and exits, the broadcasting range will shrink to 60 feet or less. In many cases, a large and complex office architecture will require multiple access points to provide full coverage to obstructed areas.

Security concerns

Despite the many conveniences of Wi-Fi, many potential users are justifiably worried about the security of their data.

Most Wi-Fi systems contain Wired Equivalent Privacy encryption, generally in 64-bit or 128-bit versions. The 128-bit WEP includes the RC4 algorithm, the same used to secure credit card information for online shopping. It's a good idea to use the 128-bit version of WEP if it's available, but remember that a determined hacker can breach even this stronger version.

By the time you read this, new encryption standards such as the stopgap Temporal Key Integrity Protocol and the even more powerful Advanced Encryption Standard might be built into your 802.11b WLAN gear, or could be added via an online download.

Meanwhile, wireless gurus recommend commonsense measures to protect data. Change encryption keys regularly and enable Media Access Control filtering on your access points.

For securing especially mission-critical data, consider using some type of virtual private network hardware that brings hefty IP Security or the Point-To-Point Tunneling protocol to their WLANs.

J.B. Miles of Pahoa, Hawaii, writes about communications and computers. E-mail him at jbmiles@gte.net.

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