voice Feedback in cellular system

[masadi]

Dear All

During a conversation using cellular phone, sometimes i experience voice feedback (some words i'd said, i hear those words again from my cellphone's speaker). where's the source of the problem? is it in BTS, switching/MSC or anywhere else?

thanks in advance

regards

 

[alexandr22061986]

This problem is named echos. I know it in wireline network. On both sides (user-network node) in transmitters due to mismatches some part of incoming signal from receiving part can leakage in transmiting part, so it transmits in reverse direction. So the sourse of problem is transmitter of BTS.