Tuesday, September 13, 2005

Business Week: Tragedy and Telecom

"It turns out we have developed a budding broadband system that, in times of disaster, doesn't work as well, interrupts more easily, and comes back on line later than the good old copper-wire system." -- quoted from: Tragedy and Telecom - BusinessWeek Online - MSNBC.com

As the second-guessing and political maneuvering continues in the wake of the destruction of New Orlean by Hurricane Katrina, this question has been asked: "What role does the government play in specifying and ensuring the survivability of the public telecommunications infrastructure."

Interesting question, and the subject of the article cited above. The trouble is, the writer is ignorant on this topic. Most folks don't know the historical vision for the Internet, which is based on design goals set by the US Department of Defense, specifically the Defense Advanced Reseach Agency (DARPA). The first implementation of this technology was in fact called DARPANET.

You see, the goal was to build a network which could survive a nuclear war, a somewhat larger and more violent disaster than a hurricane. The traditional telephone network, called the Public Switched Telephone Network (PSTN) by telecom folks, is a hierarchical network loaded with single points of failure and capacity constraints. The DARPANET, and its successor, the Internet, is designed to be decentralized in its control function, and more adaptive in its tranmission capacity.

But regardless of the whether a network is based on PSTN or Internet technologies, the hard part is the so-called 'last mile' -- that last little bit connection to the end user. Both PSTN and Internet use copper wires and various wireless technologies for that last mile. Neither stand up well to hurricane force winds and flooding.

Because I live in a telecommuncations backwoods, my only choice for wired telephone communications is a copper pair from my house to an SBC central office about 5 miles away. Our service regularly goes out every time we get a hard rain. I've complained many times to MCI (who is our retail provider, buying the local service on a wholesale basis from SBC), and to the Public Utilities Commission of Ohio. They do some half-assed fix, like move me to another pair on the main cable, but the next time it rains real hard, we're out again. It turns out that for us, the cellular system is much more reliable, and cheaper, than the copper wire system. We may drop our wireline system altogether before long.

Most people notice the phone line wires that run along on poles, high above their heads, and think that should be a good place for wires in a flooding situation. That's partially true. The wires might be out of harm's way during a flood, but they're the most exposed option while the storm is actually taking place. You can bet that in New Orleans, miles and miles of overhead wiring has been destroyed.

So is buried cable better? Well yes, it's better protected from wind damage (including trees and poles falling through the wires), but in general is not designed to be underwater for days at a time. Additionally, the wired phone network includes lots of ground-level and below-ground-level electronics bays in environmental vaults and simple cabinets which may not survive well in a flooding situation. Oh, and then there are those big multi-million dollar exchange switches in every neighborhood, almost always on a street level floor. Again, I know that some of these pieces of equipment have been rendered inoperable in New Orleans.

So are the wireless systems really better? Well.... no. Cell towers and antennas are fragile things compared to hurricane force winds. There may be few cell towers functioning in New Orleans these days, or even standing for that matter.

Another key point regarding the design and engineering of telephone networks: Not everyone can use it at the same time. There are not enough lines in the telephone network for every telephone to be in use at the same time. In normal situations, only a fraction of the telephones are in use, and the phone company has learned the statistical profile of usage over the years. There are 1 million people in New Orleans, and 1 million people in Columbus OH, but there can't be 1 million individual phone calls taking place between those two cities -- there isn't anywhere close to enough capacity in the phone system to allow for that.

When a disaster strikes, there is an extraordinary demand for telephone services all at once. Regardless of how much of the phone system survives, there isn't enough capacity for everyone to get on and make a voice call. However, a data network, using the DARPANET/Internet technology, lends itself to getting message traffic through because it doesn't have to be real time, like a voice telephone call. I can send you an email, and it might take an hour or two to get through instead of the normal seconds, but it will get through if there is any path available. The day after Katrina, folks figured out that they could get text messages through from their cell phones even when there was no voice capacity available. This is because the text messaging uses Internet technology to move the messages around.

The Achilles Heel of all technology is the need for electricity. PSTN and Internet networks alike only operate while the switches and other devices are powered. The traditional Ma Bell PSTN phone companies have a major investment in backup power setups for their networks. They use batteries and generators, and can keep power flowing to their equipment for many hours. But that's hours. After that, the generators need to be refueled. You can be sure that there are a number of telecom facilities in New Orleans which survived the winds, rains and flooding without significant damage, but are down nonetheless because the backup generator has run out of fuel.

There's only one answer to question: How could we have kept Katrina from causing so much pain and suffering? That answer is: Don't live there. Hurricanes are big nasty storms that concentrate incredible amounts of energy. If you chose to live in a place that's prone to hurricanes and also below sea level, eventually an incredibly bad thing is going to happen. We humans pick out precarious places to live, and when the inevitable disaster happens, want to blame someone else for our own stupid decision. But that's another discussion for another time.

So I wholeheartedly disagree with this writer. The telecommunications infrastructure of New Orleans will indeed need to be rebuilt after this disaster if we are going to reoccupy this city (another questionable decision). We know the residents are going to want their Internet access, so maybe the right thing to do is rebuilt the internet system only, and not bother to spend (waste) the money required to restore the PSTN network.

If we're going to rebuild a whole major American city, let's make it a city of the future, not one of the past.

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