Live network assessment using digital signal processing

A measurement device is presented that objectively characterises an echo-path by monitoring the speech signals non-intrusively on the 4-wire part of an in-service telephony connection. The device has been implemented on a Motorola DSP56001 and original results in the form of echo-path parameters have been derived that can be used to assess the call quality as perceived by the end-to-end customers. The programmable DSP hardware has constrained the solution to using the least-mean-squares algorithm but novel strategies have been employed in order to optimise the convergence rate of the model