Why cellphones didn't work during the quake

The walls started shaking, the earth was quaking and all you wanted to do was call your relatives and reassure them that no, a brick did not fall on your head during the quake. But of course, in the hour or so following the 5.4 temblor that rocked Southern California, it wasn’t easy to make a call. Perhaps you got a busy signal, or it went straight to voice mail or it started to ring and then just dropped the call.

What gives? Why are cellphones most useless when you need them the most?

Mobile carriers project how many people will be using their phones during a crisis and try to ensure that their networks can handle that call volume, Verizon Wireless spokesman Ken Muche said. Today’s call volume was 40% higher than what Verizon had projected for a crisis. During last year’s wildfires, call volume was 600% higher, he said. Because of high call volume, Verizon had to start blocking some calls so that others could get through.

“No network has an infinite amount of capacity,” he said.

Every time you place a call, the call reaches out to the nearest cell tower and tries to connect, according to Sprint Nextel spokeswoman Kathleen Dunleavy. If it doesn’t find an open space on that site, it reaches out to the next one and pings around to different towers. In times when lots of people are using their phones, towers are all at capacity.

It doesn’t help that people keep trying and trying to make a call after their first attempt fails. So rather than handling 3 million calls, for instance, the towers have to handle 3 million people each trying five times to make a call, Dunleavy said.

There are things carriers can do in an extended emergency ...

... or if they know something like a quake is coming (by listening to toads, perhaps?).  Carriers can bring in cell towers on wheels to expand the volume they can handle, Dunleavy said, and they do for events such as the Super Bowl and political conventions to ensure that everyone who wants to make a call can do so.

Since we haven’t quite gotten to the point where we can predict earthquakes, Chinese toads notwithstanding, what’s a cellphone user to do? For once, the iPhone isn’t an answer: not even the new iPhone’s 3G network was immune to the quake, an AT&T spokesman said. (Verizon's Muche did say some handsets are better at holding onto calls than others so might drop fewer calls during peak periods.)

The good news is that text messaging and e-mail should work just fine in high call-volume situations, because both use less bandwidth than voice calls. So while you might not be able to call your relatives and tell them that you're fine, you can still text them (whether they know what a text message is is anyone's guess).

Another solution: “Push to talk” services provided by companies such as Verizon and Sprint. Operating from point to point rather than through towers, they weren’t affected by the quake or the high call volume that followed. But they work only for talking to someone a few miles away, which, in the spread-out city that is Los Angeles, probably won’t get you very far in a crisis.

Have any stories about how your cellphone worked (or didn't) during the quake? Feel free to vent in the comments below. Oh, and now would be a good time to remind you that we moderate comments, so keep it clean.

-- Alana Semuels

Semuels, a Times staff writer, covers marketing and the L.A. tech scene.

Photo: People talk on their cellphones after the quake as a fire truck rushes by. Credit: Bob Chamberlin / Los Angeles Times

Comments

[Franz Schafer]

Correction: Push-to-talk is Nationwide and in the case of Nextel International. Also a recent fiber optic cut in Pennsylvania stopped text messages too. The best thing to do is to pray.

[Franz Schafer]

Push to Talk is Nationwide and in the case of Nextel International. Texting did not work during a recent fiber optic cut in Pennsylvania even though we had signal.

[Mark M]

"Can you hear me now?"
"No."

[Cheryl E]

I actually want to switch back to Verizon-it was the only phone working in the hour right after the earthquake...A group of my co-workers were trying to get a hold of their families after we evacuated off the 6th floor, and the only phone working was a Verizon one. T-mobile, Sprint, AT&T...all out. Go figure...I dropped them 4 years ago because of bad connections. It's times like these that cell phones are needed, and it's a dissapointment when they don't.

[Ken Baerenklau]

Text messaging didn't work for me. A bit disconcerting that we had this problem after a moderate quake. Tin cans and string for the big one?

[Mike L]

Our company has an emergency voice and text alerts set up through http://www.voiceshot.com (don't know if it is ok to say their name, mod plz remove if not). It is tough to mass communicate at times of emergency and you definitely have to plan ahead to get it right.

[Ruben]

I have a Verizon phone that did not work minutes after the quake. I tried calling my mother but could not get through. I knew from past quakes that the phone system was probably burdened so I stopped. Then 'lo and behold' as soon as I stopped, I received a text message. It was my 66 y/o mother asking in texting short hand " R U OK? UR phn nt wrkng? Will wonders never cease?

[Donna L. Robinson]

I came to California from Ohio on Monday to visit my daughter and grandson, and as my daughter was out on errands, I was babysitting my grandson. When the little guy was napping, I was emailing an associate back in Ohio when the earthquake hit. All I wanted to do was call my husband in Ohio on my cell phone, have him comfort my "rattled" nerves and tell him that our grandson and I were ok. We had a 5.0 earthquake in northeast Ohio about 24 years ago, and although I got freaked out having a (very rare) earthquake in Ohio, this one seemed to scare me way more. But, not being able to call my husband made me more nervous. After several attempts, I was thankfully able to talk to him!

[Tony]

I WAS ALWAYS TOLD FOR MY FAMILY TO CALL AN OUT OF STATE CONTACT DURING A QUAKE...WELL FOR OVER $120 A MONTH AND $400 FOR AN iPHONE YOU WOULD THINK AT&T COULD AFFORD TO UPGRADE THEIR TOWERS FOR A PENDING MAJOR DISASTER THAT THE SAN ANDREAS FAULT WILL CAUSE!!!!

[Maurice]

err or the phone companies turned on the emergency switch which allows priority access to emergy services, telco staff and the civilian DR teams to communicate (the people with 2 sims in their phone)

[Melinda W.]

My family and I all have Verizon service. I was not able to complete calls to my husband or sons who are local in Los Angeles. I was able to reach my sister in Western New York, who was able to reach one of my sons by cell phone. She then tried to call me back to tell me he was okay, but couldn't get through so she sent an email.

I was able to reach my husband landline to landline.

[herbkir]

Phone networks are built on the assumption that only a portion of subscribers will demand dial tone at once, plus an additional margin for forseeable emergency situations. Here, we had every subscriber in greater Los Angeles trying to make phone calls all at once, without any advance warning to the network operators. No wonder calls were blocked. It doesn't matter what kind of phone you have. There's no way carriers can build an affordable network that can handle any amount of demand at all times.

The main conclusion I draw from this is that you can't rely on telephone service in any sudden widespread emergency, like an earthquake. Even if the network isn't damaged, congestion will block calls. (^_*)

[Larry Thomas]

Text messaging and internet did not work either!

[Cesar Bustos]

Well right after the quake i call my family using my verizon phone and did not had any trouble making the call, my co-workers tried to call but will get a busy signal from their wireless phone or landline.
i dont know is was probably just my luck.

What a bunch of bull! Do they really expect us to think that's true. It was a small localized mini earthquake. Why did land lines not work? Why did my internet continue to work? What a tactical atvantage to be able to cut off comunication from riverside to LA. What a perfect time to test something like that and blame it on too many people useing their phone. Why are mercinaries training in San Diego? What are they training for? Who do they work for? Not for me and you. Don't let this slide. People need to be held accountable. What if you were injured? What if you're child was injured? Isn't that what cell phones are for?

[Chris Sondesky]

Hurricane Charley, 2004. I had family in Punta Gorda, FL, where Charley made landfall. My grandfather, who snowbirds there, was in the Phila area for the summer. Once the news broke of the severity, we were on the next plane. We arrived on Sunday (Charley hit on Friday the 13th), and there wasn't a cell phone signal to be had. The providers had yet to bring in their COWs, and landlines were useless. There wasn't even running water for nearly a week, longer in some places. Nextel Direct Connect worked every time, providing not only civilians with reliable communication that worked NATIONWIDE (I was tlaking to friends in Philly), but locally, it was used by emergency and county workers for a quick response. Some people still berate me to this day for keeping my Nextel phone (I have another cell from a different provider), but after my experiences there, I will NEVER not have direct connect capable phone. It was a godsend, and made it so we could rough out the worst carnage I've ever seen in my life.