WiFi's next wave
- By J.B. Miles
- Jan 07, 2004
Belkin's $175 802.11g Wireless Network Access Point has a turbo mode feature that isolates it from 802.11b devices, allowing 54-Mbps speed.
New wireless access points add speed and flexibility to your WLAN
D-Link Systems' tri-mode Air Xpert DWL-7000AP works with 802.11a, b and g standards, with WPA and AES encryption. It's priced at $259.
Security concerns notwithstanding, wireless LANs are taking wing in offices throughout government. And WiFi'a contraction of wireless fidelity'is the global standard for wireless LANs.
Cahners In-Stat/MDR, a market research firm in Scottsdale, Ariz., expects sales of wireless network cards and WLAN base stations'that is, access points'to grow from $1.9 billion in 2001 to $5.2 billion in 2005.
Lower prices for WiFi components have helped boost sales. A few years ago, most wireless access points cost more than $1,000. Today you can buy a basic AP for less than $100; some WiFi adapters, once nearly $700, now sell for $50 and under.
Many new notebooks PCs and personal digital assistants include a wireless adapter. Meanwhile, WiFi standards continue to solidify.
WiFi LANs are built around a WiFi radio, which is a set of computer chips with an antenna that can send and receive transmissions from a desktop or notebook computer, PDA, cell phone, access point or other wireless device. The typical range of most wireless LANs is between 100 and 500 feet indoors, and about twice that outside depending on ground terrain and weather.
WiFi LANs employ essentially the same type of equipment as their wired counterparts; that is, adapters (network interface cards), access points, bridges, gateways and routers. The main difference is they all function wirelessly.
The wireless access points, or APs, featured in this guide function as wireless hubs or base stations designed to transmit and receive WiFi wireless data using a built-in or external antenna (or set of antennas). Traditionally, the main job of an AP is to attach to a wired LAN, which connects through a router to the Internet.
As WiFi technology has developed, however, the distinction between pure APs and wireless bridges, gateways and routers has blurred; many of the functions are now within the same box. Some wireless APs, for example, can be used as a bridge, router or as a repeater for extending the range of a wireless client. Some of them come with four-port Ethernet switches for connecting to wired networks.Different models
Many of the companies listed in the accompanying chart manufacture APs and gateway/routers separately; others have designed multifunction boxes that perform several tasks simultaneously. Depending on the complexity and size of your WiFi network, separate AP/gateway/router/bridge architectures may be preferable, or you may find it cost-effective to select a single box with multiple functions.
The first wireless LAN standard, 802.11, was approved by the Institute of Electrical and Electronics Engineers in 1997 and supported speeds up to 2 Mbps. In 1999, the IEEE approved both the 802.11a and 802.11b standards. The IEEE gave final approval to the 802.11g standard in June 2003.
WiFi components based on these three standards are faster, lower in cost and easier to set up than previous, largely proprietary generations. Check the chart on this page to see how they compare with each other.
If it seems too difficult to get your mind around the tradeoffs among the various flavors of the 802.11 wireless standard, consider a dual-band or triple-band AP. These little powerhouses contain space for at least two, if not three different WiFi radios compliant with 802.11a, b or g standards.
For flexibility and versatility, these units are hard to beat. You get 54 Mbps or 11 Mbps of speed, 64 users per access point and operation over either 2.4-GHz or the 5-GHz frequency.
If dual-band flexibility isn't enough, check the accompanying chart for tri-band APs.
Note that the accompanying chart features 802.11g and 802.11a APs, along with dual-band or triple-band units. Because 802.11b APs have become commodity items that can be found in abundance on the Internet or at retail outlets, I saw no need to feature them in this guide. Most of the vendors listed here sell at least one 802.11b AP.J.B. Miles of Honomu, Hawaii, writes about communications and computers. E-mail him at [email protected].