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Non Life Sciences => Technology => Topic started by: neilep on 18/08/2011 11:25:50

Title: What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?
Post by: neilep on 18/08/2011 11:25:50

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Title: What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?
Post by: graham.d on 18/08/2011 13:09:14

There is a two way data communication between your phone and the cell site as part of a call set up. What you hear is the effects of the radio signal from your phone interfering with nearby electronic equipment.

Title: What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?
Post by: RD on 18/08/2011 13:21:13

Q. What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?

A. http://beta.freesound.org/people/rutgermuller/sounds/50699/

Title: What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?
Post by: neilep on 18/08/2011 14:31:14

Quote from: graham.d on 18/08/2011 13:09:14

There is a two way data communication between your phone and the cell site as part of a call set up. What you hear is the effects of the radio signal from your phone interfering with nearby electronic equipment.

Thank ewe very much indeed graham !..Does this interference occur during the phone call as well ?

Title: What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?
Post by: neilep on 18/08/2011 14:32:00

Quote from: RD on 18/08/2011 13:21:13

Q. What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?

A. http://beta.freesound.org/people/rutgermuller/sounds/50699/

Fantastic RD....If only it were available on CD..I'd buy it !  [:)]

Title: What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?
Post by: graham.d on 18/08/2011 14:52:56

Quote from: neilep on 18/08/2011 14:31:14

Quote from: graham.d on 18/08/2011 13:09:14

There is a two way data communication between your phone and the cell site as part of a call set up. What you hear is the effects of the radio signal from your phone interfering with nearby electronic equipment.

Thank ewe very much indeed graham !..Does this interference occur during the phone call as well ?

Not usually. It is during the negotiation with the cell site that the phone gets keyed on and off at a frequency that is in the audio band and at high power. During a call the interference is not usually noticeable.

Title: What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?
Post by: techmind on 28/08/2011 22:55:25

The interference often does persist during a call, although usually at a much quieter level as the adaptive-transmit-power turns down the transmit power of the phone during a call if you're not far from a base station.

Also you'll only get the brrrrrrpp brrrp de brrpp de brrrp brrrrp brrrp noise during "2G" GSM communications as this pulses the transmission into 217Hz bursts. If you're communicating using a funky 3G network you won't get the same interference as this newer technology doesn't pulse the transmitter in the same way.

Title: What's The Noise Heard On A Speaker/Radio Before My Mobile Phone Rings ?
Post by: techmind on 28/08/2011 22:57:59

One day I'll configure a snippet of a recording of the brrrrrrpp brrrp de brrpp de brrrp brrrrp brrrp sound as my SMS alert sound-effect. Geeky!