The Every 55 Minute Cell Phone Curse
Fri Aug 17th 2007, 4:58pm
For quite some time now, I've suffered with this annoying tapping noise my cell phone produces when placed near speakers of any kind. Like the clock radio I have on my night stand, when I'm trying to sleep (I have to keep my phone near me at night for my job, just in case).


(drumming to a beat of something very similiar to "giddy up! giddy up! giddy up let's go!")

I've seen other people's phones cause this interference, so I know it's not just me. So what the heck is it?

Finally today at work that noise came blasting out of an office right near my desk, amplified by one of my coworker's sophisticated stereo systems, assaulting all of us and disrupting work. "That's annoying" rang out from someone, as well as "man, that was loud." I guess I should be thankful I don't have his speakers on my night stand.

A bit of Google detective work finally yielded some answers. The reason? GSM, the most popular standard for mobile phones in the world, and that used by Cingular, my carrier. An article entitled That Crazy GSM Buzz was extremely informative:
"The occasional interference heard when the phone is not in use is due to the 'page repeat period' of the network," Nowak said. "This time varies a lot depending on the network setting, but the interference every 55 minutes is due to the network checking to see if your phone is still on and in the area."
Two comments posted by readers especially caught my eye:
GSM phones and flying by anonymous, 2/10/2007 12:25:10 PM

I'm a corporate pilot and that loud clicking and buzzing comes through our headsets, to the point that it can be unbearable. Usually this is while we are on the ground, getting ready for a flight, and one of the pilots is using his/her Blackberry. But occasionally we will hear it in flight, on final approach, when one of our passengers forgot to turn off their blackberry or GSM phone. As we get closer to the ground, the GSM device starts to pick up a signal and we start to hear the faint clicking and buzzing in our radios.

I'm always surprised that no one ever mentions this when they discuss allowing cell phones in flight. From my experience they definitely interfere with communications. We are also starting to see more "fly-by-wire" aircraft being produced, which use electrical wiring (hopefully well shielded) in place of the traditional cable and pulley mechanisms for flight controls. Who knows what kind of interference GSM could cause in those systems.
Public Service Communications by anonymous, 4/4/2007 5:31:54 PM

Re: the pilot who hears the GSM interference in his headphones: I listen a fair amount to various police/fire/EMS services here in the SF Bay Area, and I frequently hear that same interference on the air. For example, I've heard it in the background when a sherriff's office dispatcher is talking, and it stops as soon as he unkeys his microphone. I suspect RF from a phone in the 911 call center is getting into the dispatcher's mic, or the audio stages of the radio.

My phone also gets into the Polycom conference room phone at work - loud.
Sheesh, just when you thought cell phone use couldn't get any worse.

Visitor comments
On Fri Jan 11th 2008, 11:44am, Its because GSM/TDMA sucks! posted:
Lose the crappy europhone then!

GSM, also known as "Digital TDMA" because its what replaced TDMA, is indeed 100% of the cause of your problems.

A phone using the superior American technlogy (CDMA) or any of its successors (1xRTT, etc), not only has superior audio quality, it also has a much more uniform power output, so you totally avoid this issue.

My Cricket phone is a local-use phone, basically a landline replacement, and it NEVER has this issue. *EVER*. My girlfriend's crappy Cellular One/Cingular/AT&T service (they keep changing the company name for a reason, folks - its rubbish!) always produces this issue whenever the phone becomes active because it relies on the inferior european network protocol standards.

If you need nationwide coverage, go with Verizon or Sprint and you won't be stuck with GSM and all its problems.

On Fri Jan 11th 2008, 2:18pm, Steve Kehlet posted:
Yes, the GSM interference is annoying, certainly enough to blog about, but it's not a compelling enough reason for me to abandon my current phone and provider. And the argument of using a US versus an overseas technology is an irrelevant one to me. Talking this over with a few people with objective opinions on the subject suggests that yes, CDMA is a superior technology, but with less than 10% worldwide adoption it looks an awful lot like Betamax. Thanks for the post.

On Fri Jan 11th 2008, 4:48pm, Oscar posted:
Yeah I have to agree with Steve on this one. The fact that there may be a better technology is irrelevant to a lot of us simply because it is not available where we live or maybe it isn't convenient to use. I love the betamax reference. We all know betamax was way better, but we all know what happened to that. Its all about market adoption and practicality.

I actually found a useful side effect to the annoying buzzing. Outside of the normal cycle when the phone "checks in" you can actually count on this noise being an indicator of an incoming call or message just by your computer speaker's reaction. So if you're in an office and want to be quiet, you can turn off your ringer and still get "notified" of a call, often a second or so before the call actually comes in.