Is 3G wireless doomed in cities?

By Felix Salmon
December 29, 2009
Phorgy says yes:

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Is AT&T’s inability to provide decent wireless broadband in tech-savvy cities like New York and San Francisco a simple matter of physics? Phorgy says yes:

At low frequencies, radio waves are kind of like molasses. They can ooze around corners and through buildings…

As frequencies increase, the waves start acting more like laser beams. They no longer ooze around corners. You start to get “shadows” or dead spots with no signal. It becomes more difficult for the signals to penetrate walls etc. These problems get worse the higher you go in frequency…

So we have two extremes: low frequency molasses waves and high frequency laser beams. As bandwidth demands increase, we begin moving the dial away from molasses (where we have good wireless signals) to laser beams (where we have dark spots, shadows, with no signal, etc).

There are many clever modulation tricks that delay the inevitable, but the basic rule is that you cannot defeat Heisenberg.

The fundamental insight here is true: smartphones operate at very high frequencies, sometimes above 2.5 GHz. And covering a city with wireless broadband at those frequencies is hard. But after a brief email exchange with Ultimi Barbarorum’s Baruch, who knows much more about this kind of thing than I do, I’m far from convinced that what we’re seeing right now with AT&T has anything to do with the hard physical limits that Phorgy is talking about.

For one thing, Phorgy’s limit of 1,000mps in total for a few city blocks is I think far higher than anything AT&T is currently able to provide. With what Baruch calls “compression, prioritisation, all that level 4-7 stuff you can do at the packet level” (don’t ask me), you can serve a lot of people with that kind of bandwidth.

But more to the point, we already have a real-world counterexample which pretty much disproves any thesis that AT&T is bumping up against Heisenbergian limits. Phorgy’s saying that the problem with New York and San Francisco is that (a) they are very high density, complete with skyscraper canyons and the like; and (b) they have lots of people all trying to use 3G cellphones at once. But there’s a city with even higher density than either of those two, with even more people using 3G cellphones, and which has no signal-quality problems at all.

Tokyo is proof positive that this can be done.

The bottleneck is money, not Heisenberg. Building a Japan-style 3G network is extremely expensive: it involves lots of high-frequency and low-frequency base stations and base station relays and femtocells and backhaul capacity and IT investment and other things I don’t pretend to understand.

And of course this kind of investment doesn’t scale. If AT&T puts enormous of money into solving the problems of New York and San Francisco, they can use similar techniques in, um, Chicago. But nowhere else in the US has that kind of density — in contrast to Japan, where density issues are endemic.

If I were an AT&T shareholder, then, I’m not sure how much money I’d want my company to spend on beefing up 3G wireless in New York and San Francisco, especially when there’s little obvious return on such an enormous investment. Sometimes you make more money with cheaper unhappy customers than with more expensive happy customers. And this could well be one of those times.

Update: Some good comments, especially from Mark. Meanwhile, Paul Krugman asks whether central Tokyo might not be such a great counterexample after all: is it maybe less dense than Manhattan? Probably depends on how you define the two areas. But there are other cities which serve just as well: Hong Kong, for example.


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From the EVP Consumer Handset Marketing, AT&T: NOOOOOOOOOOOOOOOO!!!!!

Who cares about happy customers in Chicago, or Des Moines? They don’t have blogs, printing presses, television studios, national audiences, paparazzi.

A core consumer technology marketing principle is “influencer strategy.” Don’t piss off your high income, highly active network, highly communicative customers. Those customers gain you thousands of new costumers (or lose them) based on their choices, and how happy they are with those choices.

You want Android to really have “arrived?” Find a picture in Time magazine of Brangelina with one in their hand(s).

So…ignore those Verizon ads and beef up SF, LA, NY, DC. Who really cares about anything else?

PS – how do ordinary schmucks benefit from this phenomenon? Find out what laptop Walt Mossberg is using. Buy it, and download all software and firmware updates religiously. You can be sure he never waits 24 hours to have a problem custom-fixed for him.

Posted by Dollared | Report as abusive

How interesting to hear that no one in Chicago has a television studio or a national audience. I thought I saw something last week about some billionaire lady with a daytime TV show there who is going off the air after about 25 years as an “influencer”?

Now seriously. Brangelina and other tabloid types surely influence a lot of people to do a lot of things. But there’s more to marketing than that. Otherwise no one would be paid to do it. Me, the main influence on what cell phone I have is my work. Whatever they give me, I use for work. For personal, I’m not an early adopter. I early-adopted a few things in my youth and got sick fast of them becoming obsolete, so now I wait.

Back at University of Bedrock, in my Marketing 101 class, we learned that technology adoption follows almost a bell curve, with early adopters at the left-hand tail, not that many but willing to pay a premium, and stodgy old clods like me in the big hump in the numerous but more price-sensitive middle. Of course, now that we no longer communicate by having birds peck out messages on stone tablets, this curve may have shifted to a Brangelina-loving left.

Posted by SelenesMom | Report as abusive

The “Layers 4-7″ comment refers to clever things you can do with software, as opposed to doing things to the actual physical network or its base technologies. It refers to the OSI Network Model[1], where layers 1-3 (inclusive) are the transport layers of the network and 4-7 are the software layers. (That’s a very rough guideline, and the layers model is somewhat out of date)

Some blame should, of course, be going to the FCC for allocating the spectrum inefficiently[2] as well as to AT&T for having a shitty network and shitty infrastructure. I agree with you, though, that we’re likely not close to the physical limits of our network.

That said, I’m just a network software developer, not a wireless guy, so I could be wrong.

 [2]:  /heller_on_gridl.html

-Bill Mill

Posted by llimllib | Report as abusive

The real limit isn’t Heisenberg’s, it’s (Claude) Shannon’s, and those limits only apply to limits on the capacity of a given base station. But you can always increase your capacity by increasing the number of base stations (and shrinking the amount of area covered by each station). Think wi-fi router in every home/business/room as the extreme limit.

The only case where the becomes impractical is when moving at high speeds (e.g. in a car), in which case you are limited by how quickly you can hand off from one cell tower to the next (which typically takes several seconds). But in that case you can deploy very many small base stations to deliver high speed bandwidth to users that are stationary, and ones that cover a much larger area (and provide less bandwidth) to users that are moving.

Posted by loganb | Report as abusive

It’s amazing that Phorgy can make so many technical errors and still make you worry that he’s right. For example:

“That is why the…7-800 MHz range is so valuable for cell applications.”

The 700 MHz band has never been used for cell phone communications in the US. It was auctioned off, but the spectrum is unused at present.

And we have plenty of cellular products operating in the 1.8 and 1.9 GHz bands. I started working in wireless in 1998 and I’ve never heard anyone express a concern about working in the high band instead of at 800 or 900 MHz.

“the frequencies of cell phones and even more recently, smart phones, has increased from a little over 1 GHz to over 2.5 GHz”

I’m sorry, but there’s no such thing as a “little over 1 GHz” band. In the US, most personal wireless communications uses 806-940 MHz, 1850-1990 MHz, 2400-2484 MHz and some small chunks of the 5 GHz band, along with the receive-only GPS band (1.575 GHz).

“So we have two extremes: low frequency molasses waves and high frequency laser beams. As bandwidth demands increase, we begin moving the dial away from molasses (where we have good wireless signals) to laser beams (where we have dark spots, shadows, with no signal, etc).”

Look, this is just gibberish. The highest wireless frequency band is 7x higher than the lowest. (By comparison, the difference between broadcast TV channel 2 and channel 69 was almost 20x.) But the frequency of light is 10,000 times higher than Wi-Fi. The notion that moving up 7x is the same as moving up by a factor of 10,000 is just plain wrong.

There are major propagation differences between 800 MHz and 5.8 GHz. You need more power or more base stations to provide the same coverage at higher frequencies. But the difference is hardly prohibitive in much the same way that people didn’t consider UHF to be unusable for broadcast TV.

Posted by Mark94131 | Report as abusive

I live in Tokyo and use IPhone on Softbank 3G. Softbank is know to be quite bad, relatively. There are often spots that I have no connection, but the strangest is always the places where I have connection, like in the office, it seems more to behave like a lighthouse than a constant connection. So for a few seconds your connection is good, and then it is gone again, and then back to good, etcetera.
Docomo has much more steady connection and much better connection in genereal.
Tokyo inner city is much less dense high rise than Manhattan. I live on the 46th floor, but that is slightly outside the centre and one of the higher buildings around anyway. Main roads are wider, and so are curbs, and there is lots of traintracks going through Tokyo.

Posted by Dukey | Report as abusive

If only it were about physics, then we could shift the debate from Heisenberg to Feynman and from there to Schrödinger, with AT&T deservedly as the cat.

But it isn’t. It’s about money, as usual: in this case, about what the private monopoly providers have really been doing with the massive public subsidies granted them allegedly in order that they provide service as advertised to their subscribers and potential subscribers, wherever they are. It’s about holding AT&T and Verizon to account, and not veering off into quantum excuses. ompanies’-big-internet-swindle-they-ch arge-you-40-for-broadband-that-costs-the m-8-to-provide/

AT&T and Verizon have had long enough to putz around with the system of providing America with world-class internet access, to little avail. Neither of these subsidized giants has the capacity to issue customer billing that makes a lick of sense much less be entrusted with delivering reliable wireless or even wired access at any price.

When it comes to actual performance, it’s like a bad script: “your call is important to us” – excuses outnumber successes every step of the way.

Now, before even thinking about pitting city against countryfolk, or invoking Heisenberg for goodness sake, it’s high time for the Public Option, pure and simple. es/2009/10/a-public-option-for-broadband .php

Posted by HBC | Report as abusive

Why So Much Hype About HDTV ?

Posted by Anonymous | Report as abusive

One of the things that mildly bothers me about the United States’ current competitive approach to telecom is that it ends up building two, or three, or ten different systems in every city. This is obviously essential to any individual company’s success, but the duplication means that we are using many times the resources – in physical equipment, electric power, and spectrum – that are required. Worse, it’s not even done in a way that provides real redundancy, since no company’s phone will work with another’s base stations.

I do know that other countries have deliberately chosen the regulated monopoly approach, and as a result have rolled out each generation much more efficiently than the United States. I don’t know if this is the case in Japan, though.

Posted by KenInIL | Report as abusive

I live in San Francisco and had wonderful service until AT&T updated the firmware. Now I want to switch ASAP. As mentioned by others; This is not a technical issue but a quality of service, or lack thereof, issue. Admittedly I don’t live/work among the dozen or so highrizes in the city, but the majority of SF users probably spent half there time in siliconvally or the “suburbs” were the service is just as bad.

Posted by Anonymous | Report as abusive