| 摘要 |
<p>ERROR PERFORMANCE MONITORING FOR DIGITAL TRANSMISSION SYSTEMS A periodically reset flip-flop is set when an error is detected in the bit stream of a digital transmission link being monitored. A counter is incremented in response to each period during which the flip-flop is set and is decremented in response to a plurality of periods during each of which the flip-flop is not set. An alarm signal is produced if the count reaches a certain value. In the presence of the alarm signal, the number of error-free periods which must occur to decrement the counter is increased. The arrangement is less sensitive to error bursts causing false alarms than bit-error-rate monitoring arrangements.</p> |
