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Why It's So Hard To Make a Phone Call In Emergency Situations
antdude writes "BoingBoing reports on why it's 'so hard to make a phone call in emergency situations.' Quoting: '[The thing about] the radios is that they have different sizes of cells. You've got regular cells and then smaller sub-cells. You also have larger overlay macro-cells that are really big. They try to handle you within the small cell you're closest to. But it's a trade off between capacity — they'd like to have lots of small cells for that — and coverage — they don't want to put 100k small cells everywhere. So you might have a cell that covers a mile ara and then smaller cells within that that handle most of the traffic. ... In the end, it does come down to trade-offs. That's true of any network. You're interested in coverage first and then capacity. If you wanted to guarantee that a network never had an outage your capital investment would have to go up orders of magnitude beyond anything that is rational. So each network is trying to invest their budget in ways that make network appear to perform better. The cost of providing temporary extra capacity for the Boston Marathon, that's something that's in the budget and they plan for that event. But when you get something unexpected like a terrorist event, or an earthquake, or damage from a hurricane or tornado, then you have trade offs between capital and how robust your network is. Every time you have an event people say, "Oh, they didn't invest enough." But you look at New York City after Hurricane Sandy and Southern Manhattan was under 6 feet of water — all the buried infrastructure was lost.'"
I realize that TFS is a copy & paste job, but WTF? Whomever was quoted shouldn't be allowed to use a phone ever just because they can't speak coherently.
Part of it's not just whether the network fails, but how it fails. For instance, in a situation like this the network might be reconfigured to reject incoming calls to the area to keep that capacity free for people calling out. It might start throttling back voice calls to free up that capacity for emergency services and keep the data portion of the network running (and maybe drop the data portion back to 3G or even 2G so it could handle more simultaneous users). You wouldn't be able to call out, but you could still send and receive text messages. And the process for this should be in place. This kind of thing is rare and you can't predict when it'll happen, but it's a given that it will happen so the network operators should have a plan in place for what to do when it does.
And they should also be looking back to Ma Bell's studies on how to staff operators to handle phone calls. They found through a lot of study of real-world traffic that you can't staff for the average volume and successfully handle the calls. Calls tended to cluster, so if you wanted to keep wait times acceptable you had to staff for the peak volumes and accept that that meant you'd have idle capacity a lot of the time. I often get the feeling that the engineering side of the carriers understands this, but the business side doesn't quite grasp the idea of call volume not being a normal distribution.
Very much beside the point. Only a relatively small percentage of connected landlines can call out of area at the same time. If there is a reason for many people in an area to call or be called at the same time, POTS users experience congestion just like mobile phone users do.