Method of dynamically adapting the size of a jitter buffer

Abstract

The present invention relates to a receiver system in a communication system supporting packet-based communicatior (e.g., an IP-network), including a receiver, speech decoder (40) and a jitter buffer (20) for handling delay variations in the reception of a speech signal consisting of packets containing frames with encoded speech. A jitter buffer controller (50) is provided for keeping information about the functional size of the jitter buffer (20) and for providing the speech decoder (40) with control information, such that the speech decoder (40), based on that information. provides a dynamic adaptation of the size of the jitter buffer (20) using the received encoded, packetized speech signal. The invention also relates to a method of adapting the functional size of the jitter buffer of a receiver system.

Description

PRIORITY CLAIM [0001] This patent application claims priority to PCT patent application number PCT / SE01 / 01140 filed May 31, 2000.FIELD OF THE INVENTION [0002] The present invention relates, generally, to a receiver system in a communication system supporting packet-based communication of speech and data (e.g., an IP-network). More specifically, the present invention relates to a system comprising a receiver, a speech decoder and a jitter buffer for handling variations in the reception of a speech signal consisting of packets containing frames with encoded speech. BACKGROUND OF THE INVENTION [0003] One area undergoing fast development within telecommunications is voice over IP (VOIP) (e.g., Transmission Control Protocol / Internet Protocol-TCP / IP). Developments in this area initially focused on making phone calls at very low costs. Now, developments within this telecommunications area seem promising for new and different business applications. Because both speech and data use the same ...

AI Technical Summary

Benefits of technology

The solution efficiently handles irregular packet arrivals, improves perceived speech quality, and optimizes packet loss by dynamically adjusting the jitter buffer size, ensuring compliance with telephony service recommendations and maintaining continuous speech flow.

Problems solved by technology

Due to the nature of such networks, specific technical problems like the loss of packets, delay of packets, and jitter often occur.

If the size of the jitter buffer is too large, the one-way delay from mouth to ear will be too large, and the perceived quality will be degraded.

If the jitter buffer is too small, however, packets delayed more than the size of the jitter buffer will arrive too late for any speech synthesis, and will be seen as lost.

However, the above-mentioned conventional solution statically resets the jitter buffer to a certain level at the beginning of each talk-spurt.

Furthermore, if the jitter buffer size becomes too small, packets will be lost.

Similarly, if the jitter buffer becomes too large, an unnecessary delay is introduced.

In both cases, the perceived speech quality will be affected.

This is undesirable.

Moreover, because the jitter buffer is adapted only when there is a speech silence period, the problems will be even more severe during periods of long speech where no jitter buffer adaptations occur.

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