No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

Voice Feature Guide 01

Rate and give feedback :
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
PLC

PLC

Introduction

When a network or a device loses packets, the voice quality deteriorates. In practice, packet loss is inevitable. If the packet loss concealment (PLC) is enabled to compensate the signals, however, the impact of packet loss on the voice quality is reduced and the success rates of FoIP and MoIP services increases in the case of packet loss. Voice IP data is transmitted using Real-Time Transport Protocol (RTP). The DSP chip detects the sequence number of received RTP packets. If the DSP chip detects packet loss, it automatically constructs voice data based on a configured compensation algorithm and sends the data to the TDM side.

Three compensation modes are available:
  • Compensate the lost packet with the silence.
  • Compensate the lost packet with the previous packet.
  • Compensate the lost packet with a similar packet that is calculated based on the energies of the previous packet and the subsequent packet (as described in G.711 Appendix I).
The third mode consumes the most DSP resources, but improves the voice quality in the most satisfying manner. The first mode consumes the least DSP resources, but improves the voice quality in the least satisfying manner. Figure 1-132 shows the packet loss compensation using the previous packet.
Figure 1-132 Packet loss compensation using the previous packet
NOTE:
When the IP network quality is poor, if the number of consecutively lost RTP packets is greater than 2, the voice quality is still poor even if the PLC is enabled.

Reference Standards and Protocols

G.711 Appendix I

Translation
Download
Updated: 2019-02-22

Document ID: EDOC1100067358

Views: 12860

Downloads: 118

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Share
Previous Next