VoIP call delays exceed those of regular mobile calls

Evidence

In two-way communication with mobile phone, some cases the sound from the loudspeaker is captured by the microphone in it, causing the phone to send the signal back to the caller. This can happen, for example, when using the phone in the hands-free mode via a loudspeaker. In such a situation, the round trip delay is of the order of 300 ms, a result of the signal processing and other delays in both phones, and also due to transmission delays. In VoIP calls, the round trip delay is typically even longer, often more than 500 ms. Such long delays can thus cause difficulties in speaking, which motivates the implementation of echo cancellation algorithms and subsequently objective measures to measure the positive and negative effects of the algorithms. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2460

Categorization

• XREF: Connects to the practical telecom engineering dimension of the reader’s acoustic communication goals.