Want to know why your phone wont work after a terrorist attack?
 

Alot of people say that their phones switched over today in London to SOS calls only because of network overload. This is bollocks. It is so the terrorists cant talk to each other.

The first thing armies do in a war situation is to take down communications systems. It causes disruption amongst the enemy as they cant talk to each other to regroup.

Yeah heard that as well. Also it would prevend bombs going off, working on mobile comminucation

i guess terrorists can use ICQ or MSN insteed

Some people could get through.

got in touch with a friend in london this morning and he said that you couldnt call but people were texting him left right and center to make sure he was ok

in many countries the same happens on New Years Eve for a couple of minutes, I guess is done to cause disruption and confusion amongst the drunk

Hahaha :1orglaugh

That's funny :1orglaugh

Terrorists should learn to text then. Would be a lot easier for them :winkwink:

It's also to stem the flow of panic, make sure people don't start ringing out from bomb sites telling anyone they can how horrific things are.

Well, I am not going to speak on behalf of cellular technology, but it is common knowledge that with landlines the ratio of phones to available circuits required to draw dial tone is pretty high . . . like 1:50 . . . possibly higher (it has been a while since I was trained on that basic stuff).

Essentially, it means that whenever there is a catastrophe (ie: earthquake, bombing) and too many people reach for their phones at once, it will simply lock up the system, because as everyone knows, the computer's first responsibility is to itself. Getting you dial tone is simply a perk made available as long as the switch can handle its own functions.

The real reason is that the lines are closed down to allow emergency access to reach each other without having to deal themselves with an overloaded voice network.

Keep in mind that most networks base their call volumes on a standard usage pattern with normal day to day traffic. Just like server MRTGs.....

When an event like today's occurs the networks are flooded with a much more massive call volume plus a much greater call duration time than the usual traffic patterns allow for in their tolerances.

Instead of having the infrastructure crash hard and burn for all people ( including the emergency folks) the powers that be merely shut down the voice network to allow emergency traffic to pass and restore to normal later when a few hours pass from the main impact point of the event.

Actually the capacity on the mobile network for Emergency services is always blocked off and protected, they always have plenty of 'bandwidth' what ever happens.

They can also manage the network capacity with techniques such as call gapping if they really wanted too.

Wow I didnt know that...

B.D. is correct. After 8 years in telco, the reason there is a problem with there is an emergency is because of the ratio. Obviously there is little real chance that everyone in a town will be on the phone at the same time, hence there is not 100,000 copper loops, or pairs for a town of 100,000. Like B.D. I can't recall the ratio, but I believe it's even higher that the 1:50. I wanna say it's in the hundreds, but I could be mistaken.

Anyways, it works on the same philosophy as a business. Big business (unless a call center, or something like that), depending on phone usage is anywhere from a 1:5, or 1:24 ratio. Meaning one phone line per 5 phone users. This is where people get into taking a 24 channel voice T1, or PRI and splitting off channels, and how they manage their telco services.

When you call a big company, and you can't get through, a lot of times they either they do not have their phone system/routers in the correct configuration for their usage, or they are out of trunks. A lot of time they will need to add in another PRI/T1 all depending.

Anyways, back on topic. If the city had 100,000 households, I've guess their central office would have maybe 25,000 trunks. Depending on how the network's configured (on number of T1's, PRi's, ig biz, etc versus 1 line users) all will have an effect. If the town's hit by something that gets more than the law of average's picking up phones, then you get the switch is busy, or whatever that error message is.

Telco does everything on the laws of numbers, and track things. So they base trunks, by average call times, volumes, and so forth. Average call is 4 minutes, and if there are more of them for longer, it fucks up the network of averages.

I would assume a cellular network is set up on some similar predication as well for network management, but my background's in land line telco.

:pimp

interesting...

i wander if that's true

but then again i don't think it's true.

it happened in israel every time when there was a bombing, but when't it's a one man suicide bombing, who is it going to prevent from using the phone exactly?

hahaha... the conspiracy theories that get posted as "facts" around here are truly amazing

Excellent...and while you're "wandering", you can "wonder" where you're "wandering" to...

;)

J.

[insert "You Win The Prize" pic here]

That's pretty clever...

where is the proof of this?

it's on the internet. in particular, on gfy.

isn't that enough?

Ross=tosser

duke

Not an unreasonable theory but this isn't 24. These guys have plenty of ways of communicating.

Overload is the primary reason - shutting down cell towers to phone users takes time; won't do much anyways to stop many forms of terror attacks - it's believed the bombs in the recent London attack were on timed delay; not detonated in real-time.

With all that said, the tactic of selectively shutting down cell towers has been utilized in the U.S. during some protests to make it more difficult for protesters to coordinate their activities.

Ron

you left a few things out but for the most part you are correct.

If the phone system can handle "Idol" voters, it can handle post attack calls

That's a side benefit, but its because of the ratio's as stated in the posts above.

Glad to hear my 30 years did not go to waste :winkwink:

Earthquakes present an additional problem because they knock phone off hook. This is probably less of a problem these days since so many phones have on/off buttons, but the ratio problem has always been a problem.

And emergency lines are blocked differently.

You're all wrong. If the phones in GB aren't working it's obviously Bush's fault.


:D

:1orglaugh :1orglaugh :1orglaugh

that's an overload - too many people call someone at new years eve to wish a happy new year