TESTING TELECOMMUNICATIONS EQUIPMENT

摘要

A communications system is tested to simulate a realistic conversation. A first measurement device make a call, through the system it is testing, to a second measurement device and the two devices converse using predetermined speech generated dynamically by each device in response to the signals received from the other, to simulate aspects of conversation over non-perfect communications system link. The progress of the conversation will therefore take different courses according to the quality of the link. For example, if an expected signal is detected by one device, it transmits an appropriate predetermined response to the other device. However, if the expected signal is corrupted, or not received at all, different predetermined responses (or no response at all) are transmitted to the other device. This in turn may cause the other device to repeat the original signal. Because all the responses, including those to poor quality signals, are predetermined, each device can readily determine the quality of the signals received, because each signal received by one device form the other must be one of a limited number of possible responses to the last transmission made by the one device to the other. The devices perform measurements on the sounds they receive from each other, and monitor the progress of the conversation to compute parameters describing aspects of the received signal quality.