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Hello All, Suppose I want to test if echo is induced during transmission through a network. I send a predetermined messsage from the farside and on the nearend, I compare this transmitted predetermined message (from the farend)with the original message. From there I try to detect if there is any amount of echo present. My question is: suppose due to packet drops, the parts of the predetermined speech from farend failed to arrive at the nearend. Wouldn't this "fool" an echo canceller? When I say "fool", I meant the echo canceller might try to adapted to the missing part of the speech which will result in the wrong calculation of return loss? I guess what I really want to ask is does G.168 differentiate between echo and packet drops in a signal to be measured. Another question wrt return loss measurement. Suppose there exists various degree of network latency, does a "typical" echo canceller need to continuously realign the 2 signals in time domain (say in the above setup) in order to measure return loss correctly? Thanks in advance. John |
error signal
Started by ●February 20, 2002
