Echo Canceller Performance Testing via Timed Simulated Echo
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Testing echo cancellers in telecommunications networks is challenging when there are additional echo cancellers in the path, as they cancel a significant portion of the echo, making it impossible to determine the performance of the target echo canceller.
Innovation Solution
A simulated echo signal is launched from the terminating test equipment, timed to arrive at the tandem echo canceller before it can cancel, and at the target echo canceller when it can, allowing the target echo canceller to cancel the signal, thus isolating its performance measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If test equipment is deployed at particular points in the field to test echo cancellers, then measurement precision is improved, but device complexity and deployment cost increase
Solution Approach 1:
A simulated echo signal is introduced as an intermediary element to enable remote testing. The simulated echo, generated by terminating test equipment, travels through the telecommunications path and allows the target echo canceller to be tested without requiring physical deployment of test equipment at intermediate points. This intermediary signal enables measurement while avoiding the complexity of field deployment.
Solution Approach 2:
Instead of deploying physical test equipment at field points, the invention creates a copy of the echo signal that can be transmitted and measured remotely. The simulated echo signal replicates the characteristics of a real echo, allowing the target echo canceller to process and cancel it, with the cancellation performance then measurable at the originating test equipment location.
2Adaptability or versatility
If tandem echo cancellers are present in the test path, then the target echo canceller can be tested in a realistic network configuration, but measurement precision deteriorates because tandem cancellers cancel the echo before it reaches the target
Solution Approach 1:
The simulated echo signal is timed to arrive at the target echo canceller before the tandem echo cancellers can process and cancel it. By controlling the timing of signal injection, the test ensures that the target echo canceller receives and processes the echo first, allowing its performance to be measured independently before any cancellation by tandem devices occurs.
Solution Approach 2:
The timing of the simulated echo signal is dynamically adjusted to optimize measurement conditions. The signal is injected at specific time intervals relative to the test signal transmission, ensuring that it reaches the target echo canceller at the optimal moment for cancellation while preventing premature cancellation by tandem devices. This dynamic timing control enables accurate measurement in realistic network configurations.
Data Source
AI summary
The performance of an echo canceller is assessed using a) a test signal launched from originating test equipment and b) a simulated echo of the test signal launched from terminating test equipment. The launch of the simulated echo signal is timed in such a way that it arrives at the tandem echo canceller(s) at a particular point in time relative to the arrival of the test signal, at the tandem echo canceller(s), when the tandem echo canceller(s) is (are) not able to cancel the simulated echo signal. The latter thus arrives uncanceled at the target echo canceller. The launch of the simulated echo signal is further timed in such a way that it arrives at the target echo canceller at a point in time relative to the arrival of the test signal, at the target echo canceller, when the target echo canceller is able to cancel the simulated echo signal. As a result, any residual echo received at the originating test equipment is a measure of the performance of the target echo canceller exclusive of the performance of the tandem echo canceller(s).