802.11g: The Next Best Thing or the Next Last Thing

By Steven J. Vaughan-Nichols

September 30, 2002

Want to have an argument? Get a dozen people who care about the future of 802.11 networking and ask them about 802.1g's prospects and watch the fur fly and the fun begin.

Want to have an argument? Get a dozen people who care about the future of 802.11 networking and ask them about 802.1g's prospects and watch the fur fly and the fun begin.

On one side, you have people like Chris Preimesberger, wireless analyst for Evans Data who observes that, "Because the 802.11g processor uses all the same technologies as 802.11a and is backwards-compatible with 802.11b, it is expected to become a popular component in LAN construction among developers. Gemma Paulo, Senior Analyst for Enterprise & Residential Communications at In-Stat/MDR agrees and adds, "We tend to look at 802.11g, also a 2.4 GHz technology, as a kind of life extension/upgrade to 802.11b. If 802.11g indeed shows up on the market next year, we expect that 802.11g will be the 2.4 GHz technology of choice going forward."

Allen Nogee, In-Stat/MDR's Wireless Component Technology Senior Analyst, thinks that if 802.11g does show up, it will be a hit. He says simply, "If you could get higher speeds with very little price penalty, wouldn't you go for it?"

The key word, though, is "If." While Texas Instruments (TI) and Intersil, 802.11g's biggest proponents and bitter rivals are already preparing pre-standard 802.11g chip sets, the soonest 802.11g could become an official 802.11 standard would be May 2003. That alone is enough to make some analysts dismiss 802.11g as hype.

In the meantime, Atheros Communications is already shipping its second-generation 802.11a chips. And, Intersil has moved into the 802.11a business with the release of their PRISM Indigo chipset on just this month. Will there be a market left for 802.11g when it gets there?

Navin Sabharwal, Director of Residential & Networking Technologies for Allied Business Intelligence, thinks so. He believes, "g (will be a) strong interim solution regardless of when IEEE finally approves it."

Tale of the Tech Tape

Controversy has already plagued 802.11g. To finally get 802.11g out the door, by agreeing to disagree after years of 802.11 committee fights finally proved that neither one could get enough committee votes to gets its own pet 22Mbps solution official 802.11g blessing. The end result is that 802.11g is a compromise incorporating no fewer than four different wireless standards

For 802.11b compatibility, 802.11g incorporates 802.11b's Complementary Code Keying (CCK) to achieve bit transfer rates of 5.5 and 11Mbps in the 2.4Ghz band. In addition, 802.11g adopts 802.11a's Orthogonal Frequency Division Multiplexing (OFDM) for 54Mbps speeds but in the 2.4Ghz range.

802.11g also comes with a pair of optional, and incompatible, modes to achieve throughput ranges in the 22Mbps range. These are Intersil's CCK-OFDM mode with a maximum throughput of 33Mbps and TI's Packet Binary Convolutional Coding (PBCC-22), with a throughput range of 6 to 54Mbps.

Both 802.11a and 802.11g offers up to 55Mbps speeds in the lab. In the field, 802.11a delivers about 20Mbps. That may not sound like much unless you know that 802.11b's 11Mpbs theoretical speed is more often 4Mbps in practice. Early versions of 11g chipsets have real-world speeds in the 6Mbps range according to vendors.

It's also clear from early tests that 802.11g has the same, or perhaps slightly better, range than 802.11b. On the other hand, 802.11a seems to maintain a higher throughput out to the limit of its range, while 802.11g appears to run out of steam at its extreme range.

Of course, 2.4GHz, with interference from everything to satellites to microwave ovens to high-end wireless phones, has to contend with a lot of radio frequency (RF) noise. This can result in lower throughput, which in turn can effectively reduce its range. 802.11a's 5Ghz, on the other hand, has much less interference to deal with and it's part of the spectrum appears from FCC regulations likely to stay free of most other RF devices.

Finally, 802.11g can handle only three channels at once. The first generation of Aethero's chips though could handle eleven channels at once and the next generation supports thirteen channels in the US market and nineteen in Europe. Thus, in a business environment, with multiple users, even if components were delivering 55Mbps speeds, 802.11a would effectively have more bandwidth in heavy usage situations.

It's clear that neither technology is a slam-dunk over the other. Technology issues though are only part of the story.

It's In the Money

Price may play an important role in whether 802.11g gets its chance to shine. Sabharwal suspects that, "11a will become a high performance niche solution." Rather than pick one or the other, "Most customers will wait for dual band." In any case, "between b and g, g will eventually win out in price/performance and will be significantly cheaper than dual-band." Thus, the consumer market will turn to 802.11g.

Then again, maybe not. Ed Sperling, editor in chief of Electronic News knows the original equipment manufacturers who use the wireless chips and he says that, "Most vendors will likely support all the standards, including even Bluetooth. They don't care what the customer wants they'll give them everything rather than confuse them, the cost of chip is nothing. It doesn't add that much to cost of device."

That's especially true if 802.11a and combo chips that support 'a' and 'g' on a single network interface card or access point drop in price. That does seem to be happening. Competition between Intersil and Atheros is expected to drop the price of 802.11a chipsets and both companies are already working on combo chips. Atheros has already shipped a combination a, b, and experimental g chip in the Japanese market.

Indeed, Richard Redelfs, Atheros' CEO & President, sees 802.11a's future not in standalone chips but in combo chips. Agreeing with Sperling, Redelfs says that "A/b chips just need a few more gates, and when you integrate them, it just won't be that much more." For end-users, a chip that can handle any 802.11 might amount to only an "extra $10 or $15 bucks."

At the same time, all the chip vendors are working hard at putting all of an 802.11 chip set's functionality on a single CMOS chip. Once perfected, this too will reduce prices.

Meanwhile, TI has introduced the non-standard 802.11b+, which adds PBCC to 802.11b. The result is a chip that can work today with existing 802.11b networks while, with the right pairing of 802.11b+ access points and NICs can deliver 22 Mbps speeds. Again, unlike 802.11g, b+ is on the market now and delivering 802.11g like performance.

This new, off-the-beaten track technology is already finding vendors willing to deliver it. Indeed, D-Link Systems has already released its AirPro DWL-6000AP Dual-Band Wireless Access Point with dual b+ and 802.11a support. And, significantly for pure 802.11g's deployments is that it does all this while cutting the access point's price tag from $499 to $249.

What all this means, other than helping to continue to confuse customers, is that 802.11g has a hard row to hoe as a standalone standard. Will we have devices that use 802.11g? Yes, of course. Will they dominate the wireless market in 2003 and 2004, the way 802.11b did 2001 and 2002? That is another question entirely.

802.11 Planet Conference Want to learn more about 802.11g and what technology to use? Join us at the 802.11 Planet Conference & Expo, Dec. 3-5 in Santa Clara, CA. One of our sessions will answer the question Dual-Mode Chipsets: The Ultimate Solution?.



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