Title :
Voice quality of digital wireless networks under fading channel conditions
Author :
Dimolitsas, Spiros ; Corcoran, Franklin L. ; Ravishankar, Channasandra ; Bhaskar, B. R Udaya
Author_Institution :
COMSAR Labs., Clarksburg, MD, USA
Abstract :
Telephone calls will increasingly involve a large number of multi-link circuits incorporating a variety of speech coding devices. This paper presents the results of a subjective evaluation which makes the first attempt to estimate voice quality of international connections when different wireless coding methods are used in the presence of channel-impairments. The methods evaluated included: 8 kb/s VSELP, 13 kb/s RPE-LTP, 32 kb/s ADPCM, and 16 kb/s LD-CELP. From this it was concluded that when wireless cellular links are in degraded state, end-to-end network performance is unlikely to meet transmission performance standards for fixed-wireline connections. Further, fixed-radio links, which are assumed to be provisioning the international part of the connection, do not appear to be contributing to the reduced performance
Keywords :
cellular radio; differential pulse code modulation; digital radio; fading; linear predictive coding; radio links; radio networks; speech coding; speech intelligibility; voice communication; 13 kbit/s; 16 kbit/s; 32 kbit/s; 8 kbit/s; ADPCM; LD-CELP; RPE-LTP; VSELP; channel impairments; digital wireless networks; fading channel conditions; fixed radio links; fixed-wireline connections; international connections; multilink circuits; network performance; speech coding devices; subjective evaluation; transmission performance standards; voice quality; wireless cellular links; wireless coding methods; Cellular networks; Circuits; Communication switching; Degradation; Fading; Modulation coding; Pulse modulation; Speech coding; Telephony; Wireless networks;
Conference_Titel :
Vehicular Technology Conference, 1996. Mobile Technology for the Human Race., IEEE 46th
Print_ISBN :
0-7803-3157-5
DOI :
10.1109/VETEC.1996.503441
