An assessment of the audio codec performance in voice over WLAN (VoWLAN) systems

Author

Narbutt, Miroslaw ; Davis, Mark

Author_Institution

Commun. Network Res. Inst., Dublin Inst. Of Technol., Ireland

fYear

2005

fDate

17-21 July 2005

Firstpage

461

Lastpage

467

Abstract

In this paper we present results of experimental investigation into the performance of three audio codecs (ITU-T G.711, G.723.1, and G.729A) under varying load conditions on a voice over WLAN system utilizing the IEEE 802.11b wireless LAN standard. The analysis is based upon a new technique for estimating user satisfaction of speech quality calculated from packet delay and packet loss/late measurements. We also demonstrate the importance of the de-jitter buffer playout scheme for insuring speech quality. From our results we conclude that the use of the G.711 audio codec in conjunction with the new adaptive playout scheme gives the highest user satisfaction of the voice over WLAN schemes considered.

Keywords

IEEE standards; Internet telephony; audio coding; jitter; speech codecs; telecommunication standards; voice communication; wireless LAN; G.723.1; G.729A; IEEE 802.11b standard; ITU-T G.711; VoWLAN system; audio codec performance; dejitter buffer; packet delay; packet loss-late measurement; speech quality; voice over wireless local area network; Code standards; Codecs; Communication networks; Delay estimation; Frequency estimation; Intelligent networks; Jitter; Performance gain; Speech analysis; Wireless LAN;

fLanguage

English

Publisher

ieee

Conference_Titel

Mobile and Ubiquitous Systems: Networking and Services, 2005. MobiQuitous 2005. The Second Annual International Conference on

Print_ISBN

0-7695-2375-7

Type

conf

DOI

10.1109/MOBIQUITOUS.2005.66

Filename

1541026