http://www.smartdevicecentral.com/article/that+crazy+gsm+buzz/199379_1.aspx
For as long as I've used cell phones, I've heard the buzz. I'm not referring to the kind of buzz that keeps you in the "know." Instead, this particular kind of buzz is slowly but surely driving me insane. Whenever I spend a little time near electronic equipment with a speaker – anything from an alarm clock, to a television, to a high-end pair of studio monitor speakers – I can hear the buzz.
If you're on Cingular or T-Mobile, chances are you know what I'm talking about: the dreaded interference sound from your cell phone. I've experienced this interference with many different GSM phones, over a wide range of speakers. Whenever a phone is within close proximity of a speaker, the buzzing occurs every 55 minutes or so. The phone also buzzes continuously, almost maniacally, whenever someone calls or sends a text message.
This situation is affecting the way I do business. For example, whenever I receive a phone call I have to move away from my desktop PC, where I'm working, in order to take the call. Often I keep my phone on a shelf halfway across the room, if I need to have my speakers on for whatever reason (such as listening to music while working – hello?). Of course, that makes it inconvenient to answer the phone without having to get up and walk.
In many cases, the buzzing becomes so loud that anyone in the room stops what they're doing to ask me where it's coming from. In my car, it's particularly annoying. While driving on the Brooklyn-Queens Expressway here in NYC, I hear about 10 seconds worth of buzzing every minute or so through my car's speakers as the phone jumps from tower to tower, even if the car stereo is turned off.
Conference call systems in conference rooms even do it. At a recent LG press event, I was amused when I heard the buzz from someone's phone blast through a nearby PA speaker at full volume, momentarily interrupting the person speaking at the podium.
The cause of this buzzing has to do with GSM's "time division" nature. The ever-knowledgeable Keith Nowak, spokesperson for Nokia, explains it as follows: "[[With GSM]] the RF transmitter is turned on/off at a fast rate, and that 'pulsing' is often picked up by nearby devices that don't have good RF shielding. In the case of GSM the pulse rate is 217 Hz, which can be easily heard."
Verizon and Sprint CDMA phones don't have this buzzing sound because their transmitter is on most of the time, according to Nowak. As a result, the pulsing effect generally doesn't occur.
"The interference to other devices is worse the further the phone is from the cellular tower," Nowak continued. "This is because the network requires the phone to transmit at a higher level the further away it is from the tower. In addition, the interference to a device will be worse the closer the phone is to the device being interfered with."
What about the intermittent triggering? "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."
Phone vendors are aware of the problem, and fortunately for us, a solution is in the works. "Because cellular phones operate at frequencies so close to audio bands, it is not uncommon for them to occasionally drop into the range where the radio waves can be translated into sound waves by a mock radio receiver," said Vicki Livingston, the director of marketing for 3G Americas. "A new standard is currently available in draft form which provides guidance to the manufacturers of products that can act as unintentional radio receivers so they can build shielding in to their designs."
That bodes well for future phone designs. Unfortunately, there is virtually nothing you can do about it now. Currently, there's no way to avoid the buzz unless you switch to Verizon or Sprint. Of course, this really shouldn't have to be your only option since GSM (not CDMA) is the cellular network standard used in the rest of the world.
Nevertheless, I couldn't take it anymore and just switched to Verizon. Ah, the sweet sound of silence.
Jamie Lendino is the editor of Smart Device Central.