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Weekly Column

Bound and Gagged: WiMax Isn't What It Seems, But Then Nothing Else Is, Either.

Status: [CLOSED]
By Robert X. Cringely
bob@cringely.com

How much Internet bandwidth is enough? For most consumers the answer is that no amount of bandwidth is enough. We always want more. For carriers the answer is that just enough bandwidth is enough, because providing more than the minimum hurts profits. But the best rule of thumb says that the right amount of bandwidth varies with the kind of network you are using and what you are doing with it. All Internet technologies are not created equal, it seems, and the wireless varieties -- specifically 3G and WiMax -- are at a real disadvantage when it comes to bang for the bit.

This topic came to mind because Intel Capital, Intel's venture capital organization, just announced a $600 million investment in Craig McCaw's Clearwire Corporation, the poster child for national WiMax deployment. This is the largest strategic investment ever made by Intel Capital. McCaw needs $3-4 billion to build out his nationwide WiMax network while Intel has a WiMax chip business it wants to push, hence the $600 million investment. Clearwire also is selling its wireless network equipment business to Motorola for $300 million, giving Motorola a stake in the WiMax business, presumably using Intel chips, too.

This deal is all about the chips and nothing but the chips.

Of course, WiMax is pretty darned exciting, offering speeds up to 70 megabits per second at ranges up to 30 miles. It really ought to give DSL and cable modems a run for their money.

Or will it?

WiMax, like most wireless networking technologies, is either-or. You can either have lots of bandwidth or you can have long range. There are exceptions to this rule if you have line-of-sight transmission and can use a matched set of high-gain antennas. Then, sure, WiMax can send those 70+ megabits per second for 30 miles and more -- sometimes a LOT more. But the way most of us envision using WiMax is with lower gain antennas, often without line of sight, and possibly even while moving from place to place, so the trade-off of bandwidth for distance is pretty severe. Most WiMax users will find that they can't get the target 70 megabits per second at 30 miles. They'll be lucky to get even one megabit per second at 30 miles. Possibly a LOT less, as WiMax's adaptive modulation slows transmission and throws on lots of forward error correction to make sure the signal gets through, however sluggishly.

If your WiMax or 3G connection syncs at, say, 100 kbps, does it still qualify as broadband?

Maybe it doesn't matter. Again, it depends on what you are doing with that bandwidth. I have had an Internet connection of at least 384 kilobits-per-second since 1997, with my present setup totaling a supposed 13.5 megabits per second and up to eight megabits of that available for a single communication session. That's nearly a 40-to-1 increase over nine years, yet I have a hard time claiming that my Internet performance is any better today than it was back then. Today we do a lot more big file downloads and a lot more audio and video, but the major limiting factor once your pipe gets big enough is simply how much bandwidth the server on the other end will allow you. I can have eight megabits available, but if the servers at YouTube or iTunes will only allow me a quarter to a third of that amount, well then that's what I am stuck with. I can support more simultaneous users on my LAN, but I can't get my stuff any faster than those other guys will send it.

But the WiMax problem goes deeper than that. There's the dream and then there's the reality. The dream is watching Friends in HD video, downloaded over my WiMax connection. The reality is that this is possible, but only very close to the cell tower, which means that WiMax cells will end up being smaller than predicted and will require more Internet backbone bandwidth (because there are more cells) to support fewer users (because of attenuation). There is no free lunch. WiMax won't require cable pulls and relocations will be easy, but in terms of dollars per bit, it has to be more expensive than DSL or cable modems, so don't look for a pricing breakthrough.

Remember that those other networking technologies are piggybacked on telephone and cable circuits that were paid for decades ago, too, and they have the benefit of a decade or more of refinement.

The really formidable competitor, it seems to me, is the cable modem. Because for all the arguments about how many users have to share how much bandwidth on this bus network, cable systems today mainly cram their Internet users into 6 Mhz -- a single analog TV channel. All it takes to double bandwidth, then, is to sacrifice a TV channel hardly anyone watches (my preference would be the TV Guide Channel). Or switch everyone to digital cable and reclaim several channels for Internet use. A lot can be improved by simply adding more bandwidth, as Dan Bricklin explains in one of this week's links, and cable TV has probably the greatest total bandwidth potential.

DSL can reach speeds as fast as 25 megabits per second, but in the U.S. we rarely see more than 6-8 megabits. And again this is distance dependent. To get the higher speed you have to be pretty much sitting atop the telephone company Central Office. But there's more. The speed of ADSL is limited by crosstalk within a pair of wires and between wire pairs in the same binder group (the same bundle of wires). Throw a lot of essentially identical data streams on there (that would be IPTV real-time streams mimicking a cable system) and the crosstalk gets worse, a lot worse. This is why telcos with copper wiring plants (almost everyone) really don't want to offer television.

Here's how this was explained to me by a friend from BellSouth, my local phone company: "We talk about our only two assets: the wire (network) and the customer. To maintain the wire is a fixed cost. To keep a customer is a fixed cost. Furthermore to get a customer is fixed somewhat within verticals -- consumer DSL, Business DSL, Consumer phone, etc. To this end the business meetings at Bellsouth are never about dollars but about customers gained, customers maintained and customers lost. The point is they are geared toward maintaining and utilizing the infrastructure. BellSouth does not want IPTV. It is expensive, complex and will use tons of bandwidth -- more bandwidth than they even have. But when you look at it from customer loss/maintain/gain it is their only option."

So we have two communication giants fighting over our data service, overbuilding infrastructure with no failover except for whackos like me with both cable and DSL connected through twin-WAN routers. Now WiMax will enter the fray and 3G cellular, too, though 3G will never even try to compete on price and WiMax will probably only pretend to. And don't forget Broadband over Power Lines (BPL) which will eventually be here with the odd characteristic of 100 percent market penetration, since every home has electricity and every home will get a smart electric meter that speaks only IP.

It's overbuilding and under provisioning. I was talking recently with a BPL executive who is planning to provision 90 megabits per second of Internet bandwidth for every 180 homes (500 kbps per home) which is about three times more than most telcos are planning for (and at least 10 times more than they have today) and he was wasn't even trying to handle video, too.

Reality sets in. And it doesn't look good.

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