Why wireless calls can fail in disaster

[jones]

Why wireless calls can fail in disaster
Landlines are key; can engineers plan for 'apocalypse'?

By Jeffry Bartash, MarketWatch
Last Update: 12:01 AM ET Sept. 17, 2005


WASHINGTON (MarketWatch) -- When a major disaster strikes, wireless phones don't always work.

Thousands of customers found that out the hard way after Hurricane Katrina devastated large swaths of the Gulf Coast, including New Orleans. Similar, though less widespread, interruptions afflicted the New York City area after the Sept. 11 attacks.

The crux of the problem is simple. Unbeknownst to many subscribers, wireless calls in the United States travel partly over old-fashioned wireline phone networks. When those systems encounter trouble like severed cables -- or in the case of New Orleans, massive flooding -- wireless networks can also fail.

"You can be as waterproof as you want, but when you get hit with a 25-foot surge there is nothing you can do."

BellSouth spokesman


The same problems are likely to arise in future disasters where the scale of damage is comparable, such as a major earthquake. Even though phone companies spend billions of dollars each year to maintain or upgrade networks, they're not immune to failure.

Trying to make them disaster-proof, moreover, is an impossibly expensive notion, industry officials say.

"We do everything we can that is reasonable without charging customers $600 a month," said Jason Hillery, a spokesman at SBC Communications Inc. (SBC: news, chart, profile) , the main local phone company in California.

How wireless works

A common misperception is that wireless phone signals move exclusively through the airwaves, but that's not how it really works.

When a subscriber makes a call, the signal is picked up by the nearest wireless antenna. The signal travels down to a "base station" at the bottom. The base station, in turn, is connected by a high-capacity fiber cable to a central switching office. Then the process is reversed if the recipient of a wireless call is also using a cell phone.

Some people think you make a call and it floats around ... and boom, you hear it," said Cingular Wireless spokesman Mark Siegel. Cingular is owned by BellSouth Corp. (BLS: news, chart, profile) and SBC.



Hurricane Katrina knocked out service at 19 of BellSouth's central offices, which are reinforced bunker-like structures housing very expensive equipment that switch calls to and from their intended destinations.

With the central offices down, hundreds of thousands of people lost landline phone service and countless wireless customers were cut off. Indeed, little service was available in the crucial early hours after the storm passed, making communications between emergency personnel almost nonexistent. That contributed to the ensuing chaos.

It's not as if BellSouth were unprepared for such emergencies.

The company is the main local phone company in the Southeast, where hurricanes are common. Its central offices are ruggedly built with the ability to withstand winds of 120 miles per hour or more.



Before Katrina, none of BellSouth's 1,600 central offices nationwide had been rendered inoperable by a disaster, spokesman Joe Chandler. Indeed, three of the water-damaged central offices in the Louisiana peninsula were even constructed on stilts to raise them above sea level.

"You can be as waterproof as you want, but when you get hit with a 25-foot surge there is nothing you can do," he said. "This is just a unique situation."

The quick fix

When a main central office owned by Verizon in lower Manhattan was heavily damaged on Sept. 1, 2001, the company acted quickly to restore service. Extensive temporary repairs allowed the New York Stock Exchange to reopen just one week after the terrorist attack.

For BellSouth, the problem is more complicated. Some of its central offices remain flooded and expensive electronic switches costing about $5 million each were destroyed. So far, the company has restored three of its 19 damaged central offices. Until they are fully repaired, wireless-phone calling in the New Orleans area could be spotty.

To work around the damage to its central offices, BellSouth has deployed "microwave" trucks to reestablish service temporarily. The company borrowed two of SBC's six microwave trucks.

The trucks collect landline-based phone traffic where a network is severed and sends the signals to a working central office, which reroutes the calls.

Wireless phone companies, meanwhile, have deployed a herd of "cows," an acronym for cell-sites on wheels. Cows are mobile cellular towers that can replace damaged ones.

Even with extensive temporary repairs, however, wireless and landline phone networks can get overwhelmed by sheer traffic. On Sept. 11, 2001, call volume to Manhattan, already enormous, more than doubled. While most calls got thru, many had to wait.

Similarly, calls to and from the Gulf area surged after the storm. The congestion slowed or blocked phone connections. Industry executives are emphatic about asking that customers refrain from making calls to disaster-stricken areas unless they absolutely have to.

Defending the network

Of course, the phone industry has made a lot of progress in disaster prevention, learning anew from events like the 1994 earthquake in Northridge, Calif., and the 2001 terrorist attacks.

Consider the approach taken in California. Because an earthquake in that state is among the more likely natural disasters that could strike the United States, SBC has set up an elaborate emergency-response system to take into account a variety of potential problems.

Like other big phone companies, SBC has installed reams of fiber that possess "self-healing" properties. When calls reach the end of severed cable, they circle back to find an unbroken connection to a central office. Fiber can also carry far more traffic than the old copper cables.

Damage to power grids could also present a big problem in an earthquake. Yet as long as SBC can get physical access to central offices, the company can supply fuel to keep backup generators running.

Big microwave trucks, meanwhile, could quickly reconnect cities whose communications were cut off by an earthquake.

SBC monitors the health of its network around the clock with an emergency center linked to the U.S. Homeland Security Department and to state officials. The company also operates regional and local emergency sites that can respond quickly to problems. Emergency personnel can all communicate via satellite phones, the only reliable communications devices in disasters.

Nonetheless, engineers have not found foolproof ways to fool Mother Nature.

"I don't think anyone can engineer for an apocalypse," said Siegel of Cingular. "It's an exaggeration, but not much."


Jeffry Bartash is a reporter for MarketWatch in Washington.

Why wireless calls can fail in disaster

[Jay2TheRescue]

Wired networks have their faults too. On Sept 11, 2001 I was at my office on Quantico Marine Corps Base in Virgiinia. Cell phones were down. There wasn't good coverage on the base then anyway - just stray signal that came over the river from Maryland. Regular landlines were overloaded. I was able to get a dial tone on a DSN line (Defense Secure Network) but encountered problems when trying to call outside the network to a civillian line. None of our communications networks can handle the volume of calls associated with a large scale emergency. A few years back I remember cellular service was also disrupted when we had a 110 car accident on I-95 in a snowstorm.

[Yankees368]

That was a great article explaining what exactly happens to the network in a disaster. Lets have the mayor or New Orleans read it, so he takes back that statement he made. lol

[ShoresGuy]

That's a very good article and definitely shows that the fire and police departments should have unlimited access to satellite phone services so they can use alternate communications when their radios and phones don't work.

[Andy]

I agree, very good article. Shoresguy made some good comments there, and I have to agree.

[Jay2TheRescue]

Originally Posted by ShoresGuy

That's a very good article and definitely shows that the fire and police departments should have unlimited access to satellite phone services so they can use alternate communications when their radios and phones don't work.

When I was an officer in the rescue squad I was going to have my phone set up for priority network access in emergencies, but I never got around to doing it.

[forrest1]

The best communications mode in a disaster is probably still HAM RADIO.

The entire USA is covered with VHF repeaters that make it possible to communicate over thousands of square miles with a small handheld radio only slightly larger than a modern cell phone ( and a lot smaller than the early cell phones!). Think of it as a wide-coverage "cell". From my home in San Diego, I can easily access several repeaters distributed around southern California.

There are limitations, of course. It is prohibited to use for business communications, so you can't dispatch cabs or pizza trucks with it. But it is ideal for emergency communications, and there are no restrictions there. You do need a license, but Morse code skill is no longer required, just a relatively simple written exam on basic theory and regulations, for an entry-level license.

Repeaters are usually well set up for emergency use, being perched on mountaintops or other effective locations, and fortified to withstand storms, winds, etc. Usually with emergency or backup power, often solar powered out here in the West. Many have a phone link so you can make a phone call. Some are cross-linked to other repeaters, so you can communicate over a multi-state area.

Ham radio got very little press with Katrina, but it was there. I'm not sure how many people carry around a handheld any more: I used to have one in the car at all times, for emergency, and just to phone the wife, but since I've started carrying a cell phone, I no longer bring the radio. I might regret that when "the Big One" hits.

Forrest

[Fire14]

Originally Posted by Jay2TheRescue

When I was an officer in the rescue squad I was going to have my phone set up for priority network access in emergencies, but I never got around to doing it.

I called to have this done & unless the dept. set it up with phones for everyone, they won't do it for individual user's.
I thought that was a poor decision since most people don't get phones from there work in the fire, police or ems fields and especially for volunteer agencies.

[Jay2TheRescue]

Originally Posted by Fire14

I called to have this done & unless the dept. set it up with phones for everyone, they won't do it for individual user's.
I thought that was a poor decision since most people don't get phones from there work in the fire, police or ems fields and especially for volunteer agencies.

I had heard it could be done, but I didn't go any further. We were a small rural squad and operated mostly on community donations. I found it easier to communicate via cell phone because where I worked I couldn't hit a county repeater with a portable radio. It was only an issue twice - on sept 11, and the day we had the 110 car accident on I-95.

[Yankees368]

Yeah, cell phones in my area were a mess on 9/11. It just so happens that on that one day, i forgot my Voice Stream 5190 at home (the reason i never leave the house w/o a phone on me). When i got home, i found that the phone worked 100% when calling my local area, but had to try several times to get a long distance call.

My parents sprint phones (one was in brooklyn and one was in rockville center LI at the time) were very difficult to reach. I think it took 10 tried each to reach.

[bobolito]

We don't have to go as far as 9/11. What about when we had the major power outage in the Northeast in 2003? Within minutes of the power outage it was very hard to make a phone call, either wireless or landline! Most of the times we were greeted by a busy tone or a voice saying "all circuits are busy". Cell service signal didn't die until hours later, at which time landlines became much more reliable.

[bobolito]

...A common misperception is that wireless phone signals move exclusively through the airwaves, but that's not how it really works....

This reminds me of one time I was testing my cell phone with my friend's while we were standing next to each other. He made a comment implying that there wouldn't be any problems since the phones were so close to each other.....LOL!

At that time I switched to "teaching mode" and explained why it wasn't any better that the phones were next to each other especially since we use different carriers.

[Jay2TheRescue]

Originally Posted by bobolito

We don't have to go as far as 9/11. What about when we had the major power outage in the Northeast in 2003? Within minutes of the power outage it was very hard to make a phone call, either wireless or landline! Most of the times we were greeted by a busy tone or a voice saying "all circuits are busy". Cell service signal didn't die until hours later, at which time landlines became much more reliable.

I don't know about that, the DC area was not effected by that outage. I would imagine that it would create problems if they couldn't keep fuel in the backup generators, or sites with battery backup simply going offline after the batteries die.

[bobolito]

The problem is not all cell sites have backup generators. I was still getting a signal after my local tower died, but it was very weak and maintaining wireless calls was difficult. My local tower didn't come back online until a day or 2 later when most of the power was restored. I guess the weak signal I was getting came from a site that had backup generator.

[Fire14]

Originally Posted by bobolito

The problem is not all cell sites have backup generators. I was still getting a signal after my local tower died, but it was very weak and maintaining wireless calls was difficult. My local tower didn't come back online until a day or 2 later when most of the power was restored. I guess the weak signal I was getting came from a site that had backup generator.

My AT&T worked for quite a few hours that day & I was in Fairfield working when that happened, the Nextels didn't go down for us, I don't know how it went after I left for coverage up there, by my home area I had cell coverage and don't remember it going down, before the power was restored.

[NYCDru]

During the blackout I recieved an analog call from my parents in Jamaica. I was using my old v60c oon the roof of a 22 story building in Manhatan.

[bobolito]

Originally Posted by NYCDru

During the blackout I recieved an analog call from my parents in Jamaica. I was using my old v60c oon the roof of a 22 story building in Manhatan.

Wow! That must have been a signal from NJ!

[roamer1]

A lot of cell sites use microwave for at least part of the backhaul from site to switch -- this, oddly enough, is especially true in the New Orleans area, where there's a lot of use of MW in general.

As for BellSouth's COs, at last report three were essentially destroyed (one, in Lake Catherine, LA, was actually *blown away* off its stilts) and will have to be rebuilt from the ground up. BellSouth will likely either bring in replacement switches-in-trailers or backhaul customers served by those COs to other operating COs (installing a DLC backhaul isn't quite as hard as installing a new switch) to get things running in the short term.

There's no two-way public communications network of *any* sort (wireless, wireline, Internet, what have you) that can handle the huge volume of traffic that a major event brings; the entire telecom industry relies on oversubscription to keep prices at a reasonable level. Giving priority to bona fide emergency users (WPS, GETS, TSP, and so on) is helpful in keeping emergency operations running, but IMO isn't the panacea that some make it out to be.

VZW in Atlanta had capacity problems on 9/11...I don't recall how other carriers fared.

-SC