Wireless Systems Design

The Enigma Of WiMAX

I’ve always tried to stay positive about new wireless technologies. I’m still positive about WiMAX (mercifully short for Worldwide Interoperability for Microwave Access), but it really is hard to say where this slick technology is headed.

A few years back, I saw and heard nothing but bad-mouthing of Bluetooth when it first emerged. Many writers called Bluetooth DOA and a waste of effort. They said it would never amount to anything. And, they asked who would be dumb enough to actually use it. Predictions where universally negative.

Thankfully, the developers and promoters of Bluetooth ignored all that trash talk and went on to create what has become the highest-volume wireless technology in use today. Check out the sales of Bluetooth chips and Bluetooth-enabled devices. The volume is higher than any one cellular technology except for GSM. Annual Bluetooth chip sales currently top $500 million per year.

When you get your technology adopted in a cell phone, you’ve got it made. Cell-phone handset sales are expected to easily top last year’s $810 million and could even hit the $1 billion mark. Even if you have your chip in only 20% of these cell phones, you’re talking about hundreds of millions in volume. And you can double that because you need one Bluetooth transceiver in the handset and the another in the headset. I call that quietly and unexpectedly successful.

What does all this have to do with WiMAX? Nothing, other than to point out that WiMAX should be so lucky as Bluetooth. While getting WiMAX chips into handsets isn’t impossible, it’s not that likely given all the competing technologies. It’s pretty early in the development and deployment of WiMAX. Even though we should be more patient, I’m getting antsy about its future.

I came back from the Broadband Wireless World conference at Caesar’s in Las Vegas in late April with mixed feelings about WiMAX. While WiMAX was the featured technology there, I was positive on one hand but began having serious doubts on the other. There has been great progress in the past year, with more and better chip sets and new end products. The basic fixed wireless standard 802.16d or 802.16-2004 is stable, and the new mobile version of the standard 16e is expected to be fully blessed in 2007. The fixed technology is here now. If you want to do WiMAX, have at it.

Yet few groups seem to be adopting this available technology, at least in the U.S. Name one wireless Internet service provider (WISP) in the U.S. It’s one thing to have the technology, but another entirely to define and test the markets and business models that bring in the bucks. Few have discovered the secret of WiMAX.

Just what are the reasons for the reluctance to adopt this excellent technology? It’s a mixed bag. For example, there is a spectrum problem, especially in the U.S. WiMAX is designed to operate in the 2- to 6-GHz range. In Europe and Asia, 3.5 GHz is very popular and available. It’s not available in the U.S. That leaves the 2.4- to 2.9-GHz and the 5.8-GHz bands. The bands around 2.5 GHz are perfect, but there are so few allocations available.

Sprint Nextel has some of the available spectrum, and a variety of potential WiMAX users are trying to identify the other owners of chunks of that spectrum that may be available for use. The 5.8-GHz unlicensed bands are available but less desirable because of the shorter range and the potential for interference from other services. But if you really want to do WiMAX now in the U.S., that band is probably your best bet.

Another factor delaying WiMAX adoption is competition from other broadband wireless services. Advanced 2.5G and 3G cell-phone data services are widely available now thanks to GSM/EDGE, WCDMA, HSDPA, and cdma2000 with EV-DO. Can WiMAX really compete? Since these are mobile services, they don’t compete with the basic fixed 802.16 standard, but they do compete with the 16e mobile version.

If you want a mobile laptop, you can easily get on the air with a PCMCIA card from Cingular, Verizon, Sprint Nextel, or other major carriers. You can see why Sprint Nextel may not want to compete with itself at this point by putting a new WiMAX service up against the 3G cell-phone infrastructure it just plowed billions into.

Another form of competition comes from the highly entrenched DSL and cable TV broadband services. One report I saw recently indicated that in the denser population areas, over 90% of PC users have broadband service. Is a wireless overlay of a WiMAX service really going to be competitive? It’s ideal for smaller cities and rural areas with no broadband services. At least that seems to be a good niche.

Besides the big emphasis on WiMAX at the broadband conference, I was surprised to see how big the municipal Wi-Fi business had become, with lots of new vendors and suppliers as well as lots of new takers. Small- and medium-sized cities are setting up Wi-Fi municipal meshes to cover the whole town with broadband wireless service, sometimes totally free and at other times for a bargain rate. Wi-Fi is heavily entrenched in laptops, and access points are dirt cheap.

Now mesh wireless software is making Wi-Fi a killer competitor to WiMAX. Who would have thought? WiMAX has a higher data rate potential and better quality-of-service possibilities. But with 802.11n and MIMO (multiple-input multiple-output) in the wings, it could get better. It probably will be a year or so more before the IEEE task group settles on a final 11n standard, and it probably will delay WiMAX adoption further.

So while WiMAX has some issues, I’m going to stay positive about it. You never can tell. It’s going to find success in Europe, Asia, and some developing countries without a normal communications infrastructure. And it will find use as a cheap back-haul method and in some rural areas where pockets of spectrum are simultaneously available. But I’m not holding my breath on major deployments in this country. The new mobile version of WiMAX has serious potential, but it will have to battle with 3G wireless and maybe even the forgotten 802.20 standard, which seems to be in limbo. As with most new wireless technologies, we can only guess where it will end up. Just keep an open mind, a positive attitude, and look for new apps and business models.

TAGS: Mobile
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