The degree of degradation imposed on signals transmitted over a communications link from a transmitter to a receiver is tested. A predetermined test signal is transmitted using spare capacity detected by a voice activity detector when no speech is to be transmitted over the communications link. The test signal received by the receiver is compared with the reference signal, and a measure of the degradation of signals caused by the communications link is generated therefrom.
申请公布号
DE60132196(D1)
申请公布日期
2008.02.14
申请号
DE2001632196
申请日期
2001.05.10
申请人
BRITISH TELECOMMUNICATIONS P.L.C.
发明人
GRAY, PHILIP;HOLLIER, MICHAEL PETER;REYNOLDS, RICHARD JOHN;RIX, ANTONY WILLIAM