Wireless LAN Devices To Get Boost


The 802.11 wireless protocols spell significant growth in sales


Wireless networking is one of the few bright spots in the current IT market, with companies, governments and educational institutions moving to meet user demand for computing without cables. As VARs step into the market, they are confronted with an array of standards,802.11a, 802.11b, 802.11g, 802.11x and others,that describe how wireless local area networks operate.

All of the standards together should add up to significant growth in the market for wireless LAN devices. Forward Concepts, a market research firm based in Tempe, Ariz., projects that total wireless networking sales will grow from $3.4 billion in 2003 to $10.3 billion in 2006.

In addition, according to projections developed by Morgan Stanley and IDC, total sales of the silicon chips that power wireless LAN devices will grow from $478 million in 2003 to $907 million in 2005, with 802.11g seeing the largest percentage growth (starting, as it does, from the smallest real revenue position). In addition, dual-band devices that combine 802.11a with either 802.11b or 802.11g are expected to become the largest portion of the total market, with $419 million in chip sales in 2005, up from $97 million in 2003.

The two companies also predict that 802.11b will show a gradual decline, from $285 million in chip sales in 2003 to $172 million in 2005, and that 802.11a will grow at a very strong rate, second only to 802.11g in percentage increase, with semiconductor sales rising from $92 million in 2003 to $274 million in 2005.

Leaving 802.11x aside for the moment,it's a security standard that doesn't deal with the basic operation of the network,it's important to understand the differences among the three main 802.11 protocols, and what those differences mean to you and your customers.

Two 802.11 standards developed by working groups of the IEEE have been fully ratified, published and are in use. 802.11b (Wi-Fi) supports a data rate of 11 Mbps on transmissions in the 2.4-GHz radio-frequency band. As there are three nonoverlapping channels within the band, VARs can deploy several access points with somewhat overlapping coverage patterns without any radio interference.

802.11a supports a 54-Mbps data rate on the 5-GHz band, which offers several advantages compared with 2.4 GHz. The biggest advantage is that there are far fewer devices using 5 GHz, so the chance of interference is greatly reduced. There are 11 channels available on the 5-GHz band, allowing greater access-point density without interference. The drawbacks include lack of international recognition, shorter transmission range and the inability of 5-GHz radio signals to penetrate most building materials.

The 802.11g standard, scheduled to be ratified and published by the middle of this year, is designed to combine features of both 802.11a and 802.11b, providing the higher throughput of 802.11a while maintaining backward-compatibility with 802.11b. Part of the compatibility involves the requirement that all 802.11g chipsets support two modulation schemes: Orthogonal Frequency Division Multiplexing (OFDM) used by 802.11a, and the complementary code keying (CCK) used by 802.11b.

There are a couple of side effects bundled with the dual-modulation plan. First, OFDM requires more energy than CCK, so 802.11g will share power-consumption characteristics with 802.11a devices; neither will last as long on a battery charge as an 802.11b device. Next, implementing 802.11g means that the software for 802.11a is essentially included for free. A second radio must, of course, be provided, but chip manufacturers such as Agere Systems, Intersil and Texas Instruments have already begun discussing their intentions to provide dual 802.11a/g chipsets when the standard is ratified.

The dual-standard chipsets are projected to become the largest portion of new access-point sales because 802.11g alone will retain some of the limitations of 802.11b. The first limitation is the 2.4-GHz radio-frequency band. Products from microwave ovens to cordless telephones use the same frequencies, making radio interference a serious concern. In addition, 802.11g is limited to the same three nonoverlapping channels used by 802.11b, a limitation that will make siting multiple access points with overlapping coverage areas trickier than with 802.11a.

What's In Store
The lack of a ratified standard hasn't prevented some vendors from beginning to ship products labeled as 802.11g. Most enterprise-class vendors are waiting for chipsets based on the final standard before announcing products, leaving customers who need higher wireless bandwidth to deploy 802.11a. The 5-GHz standard is starting to be deployed in fair numbers by VARs representing vendors such as Cisco, Proxim, Symbol Technologies and 3Com.

According to Shaun Steel, a sales representative with 3Com VAR Valcom Computer, based in Salt Lake City, his company is seeing demand from key market segments.

"The reason we're seeing a push for 802.11a is schools. You can't get enough users on 802.11b, so in schools, where the users are so dense, they're asking for 802.11a," Steel says. "802.11b is still very practical in areas where there aren't many users."

The possibility of upgrading throughput while preserving the value of existing investments has many observers predicting rapid success for 802.11g. The new standard is likely to succeed precisely because "802.11g combines the best aspects of 802.11a and 802.11b, with the speed of 802.11a, the range of 802.11b and the likely price point of 802.11b," says Keith Waryas, research manager for wireless products at IDC, Framingham, Mass.

User density will be an important consideration as more network clients move to wireless connectivity. User density is one reason 802.11a is expected to continue to grow alongside 802.11g. Dual-mode access points will allow clients to connect at the higher-density 802.11a standard when possible, with 802.11g as the longer-distance (or through-wall) option. Plans for deployment of such dual-mode wireless networks will generally include placement of primary 802.11a/g access points with 802.11a single-mode access points located at intermediate points to provide full coverage.

One concern in this scenario is the development of dual-mode wireless NICs that gracefully transition from 802.11a to 802.11g and back. Several vendors, including NetGear, Proxim, and 3Com, have released dual-mode 802.11a/b NICs, although transitions between modes are not yet smooth or reliable enough for most units.

For most VARs, the question for installation will require balancing bandwidth and user density against coverage patterns and the likelihood of interference. Whether the requirements of coverage and distance argue for 2.4 GHz or 5 GHz, by the end of the year VARs should have a high-speed option to offer customers.

Curt Franklin (kg4gwa@arrl.net) is a freelance writer based in Gainesville, Fla.