Advanced Echo Cancellation
Echo Cancellation for Today's Networks
As voice networks migrate from circuit to packet technologies, more demands are placed on hybrid and acoustic echo cancellation equipment. Latency is greater and more variable, and the increase in customer terminal equipment options makes acoustic isolation less dependable.
Ditech Networks’ Advanced Echo Cancellation solution ensures optimum network voice quality as mobile and PSTN carriers face these issues. Ditech’s industry-leading 192 ms hybrid echo tail feature and unique bidirectional acoustic echo control, which adaptively supports tail delays of up to 400 ms, allow carriers to migrate from circuit to packet voice technologies without sacrificing voice quality.
Added Delay from Packet Technologies
As IP-based voice technologies have matured, carriers have started using IP technologies in their networks to reduce operational expenses. However, a carrier must convert from circuit to packet, and most likely reverse that, prior to forwarding to another customer. This conversion adds delay, and even more delay is added due to the probabilistic nature of forwarding in packet-switched networks.
Increasing Acoustic Echo
The wide variety of customer terminal equipment has created an increasingly problematic voice quality issue for wireline and wireless carriers: acoustic echo, which occurs when signals from the terminal's speaker are reflected back into the network through the terminal's microphone.
The problem of acoustic echo is exacerbated by the wireless codec delay of about 160 ms round-trip, which is on top of the delay through the remainder of the call path. Even worse for carriers is that acoustic echo can be generated by both the calling and called party, and competitive solutions can only provide unidirectional acoustic echo control.
Measuring and Monitoring
Included in the Advanced Echo Cancellation solution is Ditech's Voice Quality Management, which helps carriers understand the types and severity of echo in their networks. With this performance information, a carrier can address voice quality issues in its own network, as well as verify the level of service that its partners are providing.