Wireless networking comes of age
Barrie Sosinsky
There's been a lot written about the various flavors of 802.11 (.11a, .11b, .11g, and the .1x standard) dubbed "WiFi", and with good reason: wireless networking has gotten fast enough, has enough transmission range, and is now cheap enough to achieve widespread corporate and consumer acceptance. The savings achieved in costly wiring projects typically pay for wireless implementations right off the bat, but in many more cases wireless networking (WLAN) makes some networking projects practical that simply weren't affordable before. WLAN is one of the "breakout" technologies of 2001.
The 11-Mbps 802.11b standard appeared 1999. Today street prices for wireless NICs are $100 to $200 with access points (wireless routers that connect to a LAN) cost anywhere from $300 to $800. Vendors include: Agere Systems, Intel, Intermec Technologies, Cisco Systems, Avaya, D-Link Systems, 3Com, Proxim, and Symbol Technologies.
The 54-Mbps 802.11a (the so called WiFi5) standard also ratified by IEEE in 1999, is just now coming to stores from vendors such as: Intel, Proxim, and Intermec, and others. Not only is it faster, 802.11a uses a 5-GHz carrier frequency that doesn't interfere with many consumer devices. 802.11b devices share their band with cordless phones, Bluetooth wireless devices and microwave ovens, which can cause interference.
The 802.11g standard is a 2.4-GHz 54-Mbps WLAN, and the first devices in this standard should appear later in 2002. Reports are that the .11g standard has diminished range and has the same security issues of 802.11b; but it does offer better interoperability with existing 802.11b devices than the 802.11a standard.
In reality 802.11a and 802.11b do not deliver 54-Mbps and 11-Mbps speeds; their effective throughputs respectively, are roughly 27 Mbps and 6 Mbps. 802.11b is supposed to have an advantage over 802.11a in its ability to penetrate walls and communicate around corners. Devices compliant with both standards have a range of around 300 feet, but both have their throughputs drop off substantially over that range.
There are compatibility issues between these two standards, so if you invested in 802.11b you want to be careful about 802.11a purchases or investigate the more compatible 802.11g standard, which is coming to market soon. The group certifying compatibility is the Wireless Ethernet Compatibility Alliance or WECA, They issue the Wi-Fi (802.11b) logo. WECA will begin interoperability testing of 802.11a products, and 802.11g products when they appear.
In selecting wireless networking hardware, pay particular attention to the quality of the vendor's security implementation when you make your purchases. There are known security problems in the Wired Equivalent Privacy (WEP) protocol used in 802.11-based wireless LANs. WEP uses the RC4 encryption algorithm with a 40-bit key, and those encryption keys have been broken.
Barrie Sosinsky (barries@killerapps.com)is president of consulting company Sosinsky and Associates (Medfield MA). He has written extensively on a variety of computer topics. His company specializes in custom software (database and Web related), training and technical documentation.
