Title: Subjective audio quality over a secure IEEE 802.11n network

Authors: Benjamin W. Ramsey, Barry E. Mullins, Ryan W. Thomas, Todd R. Andel

Addresses: 754th Electronic Systems Group, 200 East Moore Drive, Maxwell AFB–Gunter Annex, AL 36114, USA. ' Department of Electrical and Computer Engineering, Air Force Institute of Technology, 2950 Hobson Way, AFIT/ENG, Wright-Patterson AFB, OH 45433-7765, USA. ' Department of Electrical and Computer Engineering, Air Force Institute of Technology, 2950 Hobson Way, AFIT/ENG, Wright-Patterson AFB, OH 45433-7765, USA. ' Department of Electrical and Computer Engineering, Air Force Institute of Technology, 2950 Hobson Way, AFIT/ENG, Wright-Patterson AFB, OH 45433-7765, USA

Abstract: This paper presents an empirical evaluation of audio quality generated by a G.711 codec and transmitted over IEEE 802.11n, IEEE 802.11b, and IEEE 802.11g Wireless Local Area Networks (WLANs). Audio quality decline due to additional calls or by securing the WLAN with Internet Protocol Security (IPsec) is quantified. Results suggest that audio quality over an IEEE 802.11n WLAN is not higher than over an IEEE 802.11b WLAN for up to 10 simultaneous calls. The data strongly suggest that toll quality audio (MOS ≥ 4.0) is not currently practical over IEEE 802.11 WLANs secured with WPA2, even using the G.711 codec.

Keywords: voice over IP; IEEE 802.11n; empirical evaluation; IPSec; MOS; mean opinion score; VoIP; subjective quality; audio quality; wireless LANs; local area networks; WLANs; internet protocol security; G.711 codec.

DOI: 10.1504/IJSN.2011.039633

International Journal of Security and Networks, 2011 Vol.6 No.1, pp.53 - 63

Received: 04 Sep 2009
Accepted: 26 Jun 2010
Published online: 12 Apr 2011 *

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