Not so long ago, the terrain of the wireless world seemed rough, wild, and desolate. The complexity of products and interoperability issues-not to mention high costs-kept consumers and businesses alike from embracing wireless networks. This despite their obvious lure: the freedom to roam untethered without losing a connection.
That lure has kept manufacturers and engineers returning repeatedly to their drawing boards to refine standards and hardware, and their efforts have paid off. By the end of this year, 1 million households in the United States will have wireless networks, according to research firm Gartner Dataquest. Among PC Magazine readers, 51 percent have home networks, and of those, 36 percent are wireless. With two official 802.11 standards and one on the way, the landscape continues to grow.
The most hyped addition to the wireless space in the past year has been 802.11g, though it isn't yet a ratified standard (the IEEE expects to approve the standard sometime this summer). Nevertheless, several manufacturers have decided not to wait and have released draft-compliant, or prestandard, 802.11g products. Ratification ensures that all manufacturers are using a standard blueprint to develop compatible products; hence, you run the risk of facing interoperability issues with prestandard "g" products. But manufacturers promise that such products can be brought up to spec via firmware upgrades; in fact, some already have released upgrades to match changes that have arisen during the ratification process.
The 802.11g specification operates in the same 2.4-GHz radio band as the existing 802.11b specification and is backward-compatible with 802.11b products. This means that "b" and "g" clients can share the same wireless network. The difference between the two is that the "g" standard allows for much higher performance.
A wireless network's throughput depends on many factors, such as building construction and the distance between the wireless client (a wireless card inside a notebook PC, for example) and the wireless access point or router (the base station of a wireless network). But in general, an 802.11g product can achieve a useful throughput of 15 to 20 Mbps within 20 to 60 feet of the access point. At best, 802.11b products reach 4 to 6 Mbps within the same distance range. The third standard, 802.11a, performs similarly to 802.11g but at distances that are significantly shorter than those 802.11g and 802.11b will reach.
The 802.11a standard made a big splash when products debuted last year, but it has failed to take off with consumers. Unlike 802.11b and 802.11g, 802.11a operates in the 5-GHz spectrum. But one advantage that "a" has over "g" is the increased number of channels available in the 5-GHz band-12 in the U.S. versus three for 2.4 GHz. This potentially makes 802.11a valuable for large-scale enterprise installations: More channels supports a higher density of users per access point in a given space.
Both "a" and "g" products share the same signal modulation technique, known as orthogonal frequency division multiplexing (OFDM). This is what gives the two standards a higher throughput than 802.11b, which uses the less efficient direct-sequence spread spectrum (DSSS) method. When 802.11g clients and 802.11b clients share a network, the access point must handle both OFDM and DSSS transmissions; the result of the overhead is a lag in performance for the "g" clients, sometimes so severe that they perform worse than the "b" clients.
This brings us to the question many consumers have: Is "g" ready for prime time? We think so, especially for those buying their first WLAN hardware for their homes or small offices and not scared by the prospect of updating their firmware. Those who are uneasy with that prospect should hold off until the specification has been ratified. Likewise, those concerned about interoperability with the WLAN equipment they already own should also wait both for ratification and for the Wi-Fi Alliance to commence interoperability testing on 802.11g products.
Our testing shows that manufacturers have some more work to do before the current pre-802.11g products live up to the marketing hype-especially when it comes to operating in dual mode, in which both "b" and "g" clients are supported by the same AP.
For those shopping for an enterprise, the combination products such as 802.11a/g APs may make the most sense, because they maximize the density of your WLAN. But once again, you're better off waiting until 802.11g is legit: IT dollars are too few and far between right now for enterprises to bring in nonspec technology.
When 802.11g is ratified, there's no doubt the landscape will change significantly once again. Not only will the sheer number of products available on the market expand exponentially (visit www.wifialliance.org and click on certified products, then submit with the default Show All selected in all three categories to get some idea), but the number of major chipset manufacturers producing the key components for AP and router manufacturers will grow, too. Currently, wireless chipset manufacturers include Agere (formerly Lucent), Atheros, Broadcom, Cisco (based largely on its acquisition of Radiata), Intersil, and Texas Instruments.
The number of specifications handled by each product will change as well. Linksys, which was acquired by Cisco in March, has already introduced the first 802.11a/g (which, in effect, includes "b") combination consumer router/access point (the Linksys WRT55AG, reviewed in this story). Our distinct hope (one shared by many manufacturers) is that within about two years the silicon manufacturing costs will be low enough that all products-whether base stations or client cards-will support all three specifications without users having to worry about which specification is being used at any particular moment. That should make equipment interoperability and user education much simpler. For now, the alphabet soup of products today includes 802.11b-only, 802.11a-only, prestandard 802.11g (which really translates to 802.11b/g), 802.11a/b, and 802.11a/g. The following reviews cover all of these types except 802.11a-only. The 18 products we look at are either standalone access points or combination access points/ routers. But because this story focuses on wireless performance, we tested only the access point aspect of the APs/routers. Each product tested included the AP or AP/router and the company's corresponding PCMCIA wireless client. The results of our exhaustive testing may surprise you
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