Faster wireless LAN technology on tap

LAS VEGAS - The potential heir-apparent technology for high-speed wireless LANs will take center stage at Comdex Fall 2002 next week.

Chip makers Intersil and Broadcom, along with a number of wireless LAN vendors using their silicon, will demonstrate wireless products based on the as-yet-unratified IEEE 802.11g specifications, which at 54M bit/sec could be successor to the popular 802.11b , or Wi-Fi, standard, which tops out at 11M bit/sec.

Proponents of 802.11g say it offers corporations an easy way to migrate their 802.11b radio infrastructures, including interface cards and access points, to a higher speed. That's because wireless LANs based on 802.11g will use the same 2.4-GHz band that 802.11b uses. The higher data rate, translating into actual throughput of about 17M to 19M bit/sec, would give users more bandwidth for an array of multimedia and other data-intensive applications.

The change also will make it easier for customers with 802.11b deployments to increase throughput without having to replace wireless LAN infrastructures. That's what has to be done today when shifting from 802.11b to 802.11a, which runs in the 5-GHz band.

Vendors say the result is a wireless LAN that has the longer range of 802.11b and the higher throughput of 802.11a. In addition, any existing 802.11b adapter card will be able to work with an 802.11g access point. That's not possible with 802.11a adapters. So network executives can replace an 802.11b access point with an 802.11g access point - or simply swap the radio cards - and existing wireless users still can connect to the network at the 802.11b data rate of 11M bit/sec. When or if 802.11g takes hold, new adapter cards can be phased in gradually, enabling these devices to join a 54M bit/sec wireless network.

The first 802.11g products might be available as early as year-end or early 2003. They'll carry a higher price tag than 802.11b products, perhaps about 20%, according to one vendor who asked not to be identified. Current prices for 802.11b adapters range from $45 to $140; for 802.11b access points, from about $385 to $1,050, depending on features. The 802.11g products are likely to complicate even further wireless LAN return-on-investment calculations for network executives.

At Comdex, Intersil will demonstrate its Prism Duette chipset, which lets the radio component in the chip handle 802.11a, 802.11b and 802.11g transmissions.

The company already has what it calls "alpha customers," most of them big Taiwanese component builders. Using Duette samples, those vendors are designing 802.11g cards that wireless LAN vendors will incorporate into access points or adapters, says Larry Ciaccia, vice president for Prism wireless products. The component builders are using samples of the Intersil chips for initial design work. Intersil plans to ship higher volumes of chips by year-end and be in full production by March.

Cisco has worked closely with Intersil , using a number of Intersil technologies, but is creating its own media access control layer and integrating Cisco management and security features. Cisco sees 802.11g as a way to give its current Aironet 802.11b wireless LAN customers the ability to shift gradually to higher throughput, without having to replace every adapter card and rewire the infrastructure.

Buffalo Technology , a major wireless LAN player in the home and small-business market, will bring out an 802.11g access point and adapter early next year, says Morikazu Sano, a vice president with the company.

At Comdex, Buffalo will have a 802.11g demonstration. Sano says companies might hold off on purchases until final IEEE ratification, but he predicts 802.11g will be extremely popular in Buffalo's target markets.

"They will purchase the 11g products right away because they are looking for a faster speed, with a better distance than 11a products today," he says.

Meanwhile, chip maker Broadcom is expected to make an 802.11g announcement at Comdex and demonstrate, with several partners, some early access points and adapter cards. One of those partners is expected to be a major wireless LAN vendor that, like Buffalo, focuses on the small-business and home market.

"With 11g, you can upgrade to 54M bit/sec, get the same range as 11b, leave your existing access points in place and upgrade them to 11a later, when you need the extra capacity," says Jeff Abramowitz, Broadcom's senior director of wireless LAN marketing. "It's a very clean message for network managers."

Complicating factors remain

But any number of issues could muddy things.

For one thing, the earliest 802.11g products might not be able to wear the 802.11g label, because the IEEE has yet to put a final stamp of approval on the standard. Several observers say they expect ratification to take place by March.

Also missing will be independent interoperability testing to guarantee that one brand of 802.11g adapter card will work with another brand of access point, especially if they're using different silicon. The Wi-Fi Alliance (WFA), which certifies wireless LAN interoperability, won't begin testing until after the IEEE ratification. According to a WFA spokesman, 802.11g testing and certification will start in the fourth quarter of next year.

Another complication is the number of channels that the various wireless LAN standards support. 802.11b and 802.11g use three channels; 802.11a uses eight. In practical terms, that means more 802.11a access points can be deployed in a given area, to support considerably more users, than is possible with 802.11b or 802.11g.

Still another drawback is that using the 2.4-GHz band could be as much of a drawback as a benefit for 802.11g. "802.11g does not do anything to mitigate the interference problem experienced by all wireless LANs at 2.4 GHz," Ken Dulaney, a Gartner analyst, wrote in an overview of 802.11g issued earlier this year. "Baby monitors, cordless phones and Bluetooth devices can all interfere with 802.11g, though [Orthogonal Frequency Division Multiplexing] is more interference-immune than other modulation schemes."

Dulaney recommends that network executives keep 802.11b deployment plans in place over the next year at least, as 802.11a products mature, and as 802.11g products enter the market and begin to replace 802.11b. After ratification and interoperability certification, the company then can specify 802.11g instead of 802.11b in requests for proposal.

A quick look at 802.11g wireless LANsNew products could triple throughput in 2.4-GHz band.
What’s cool: What’s uncool:
• 54M bit/sec data rate, estimated 17M to19M bit/sec throughput. • IEEE standard still not ratified.
• Higher throughput sustained over longer ranges than 802.11a. • No Wi-Fi Alliance interoperability testing until after ratification.
• Existing 802.11b clients still work (but at the 11M bit/sec rate). • Three channels (vs. eight for 802.11a) limits number of access points and users in a given area.

Senior Reviews Editor Keith Shaw contributed to this report.

Learn more about this topic

The ABGs of wireless LANs

Dual-mode chipsets could spell relief for network execs grappling with long-term migration issues. Network World, 05/20/02.
Insider Tip: 12 easy ways to tune your Wi-Fi network
Join the discussion
Be the first to comment on this article. Our Commenting Policies