Patent ID: 7546238

Claim:
A digital line transmission unit for carrying out compression encoding, said digital line transmission unit, comprising: an encoder/decoder including a first speech encoding unit configured to encode and decode a speech signal, a second speech encoding unit configured to encode and decode the speech signal, and a non-speech encoding unit configured to encode and decode a non-speech signal; a signal discriminator including a speech burst detector configured to detect whether an input signal to said encoder/decoder is a speech burst or speech pause, and a speech/non-speech signal discriminator for configured to determine whether the input signal is a speech signal or non-speech signal; a signal multiplexing/demultiplexing section configured to multiplex outputs of said first encoding unit, said second speech encoding unit, and said non-speech encoding unit; an operation monitoring controller configured to output a switch control signal upon determining a change in a state of congestion of a digital line; and a switching unit configured to switch the input signal between said first, second, and non-speech encoding units, upon indication of a change in the state of congestion of the digital line, the switching occurring during a detected speech pause and after terminating encoding of the input signal.