Posted: 04-January-2009 10:20:13 PM By: jahangir1983
hi dear, you can follow the links given below for your answer. i hope that they will help you:
1. www.vocal.com/echocanceller.pdf
2. www.patentstorm.us/patents/7068779/description.html
Posted: 05-January-2009 12:35:25 AM By: Hash007
EC(echo canceler) is basically a part of NSS(Network Switching System).
EC is used on PSTN side of MSC for voice circuits. There are delays in our GSM system thats why there are unacceptable echo condition, for this purpose we use EC on switching side.
Also one more information is that standard EC will provide cancellation upto 68 milliseconds on the tail circuit.
Posted: 05-January-2009 12:39:27 AM By: Hash007
Posted: 06-January-2009 01:50:26 PM By: sagitraz
Echo Canceller is basically used to eliminate
"back ground noise" in GSM networks.
The echo cancellers are typically included in the
mobile terminals and mobile switching centers
which provide a gateway to other network, such
as the public switched telephone network PSTN.
Posted: 24-January-2009 11:57:52 AM By: waqasahmad
The repetition of a sound resulting from reflection of the sound waves; "she could hear echoes of her own footsteps"
Posted: 16-April-2009 03:33:58 AM By: HamidAliKhan
Follow the link
www.patentstorm.us/patents/7068779/description.html