DocumentCode :
483631
Title :
Improving R-score of Adaptive VoIP codec in IEEE 802.16 networks
Author :
Lee, Tsung-Yin ; Pan, Jen-Yi
Author_Institution :
Dept. of Commun. Eng., Nat. Chung Cheng Univ. Chia-Yi, Chiayi
fYear :
2008
fDate :
14-16 Oct. 2008
Firstpage :
1
Lastpage :
5
Abstract :
The IEEE 802.16 system called WiMAX (Worldwide Interoperability for Microwave Access) provides quality of service (QoS) of several types for different service. The WiMAX is expected to support QoS for real time application, such as Voice over IP (VoIP). In this paper, when network congestion occurs, the VoIP bit-rate needs to be adapted to achieve the best speech quality. We propose a new scheme called Adaptive VoIP Level Coding (AVLC). VoIP is sensitive to delay and loss. According to different network conditions such as varied modulation, packet delay, packet loss, and residual time slot, we use G.722.2 codec to adapt each connectionpsilas data rate. Simulation experiments are conducted to test the performance (network delay, packet loss, and R-score) of the proposed mechanisms. In result, we increase the R-score about 40% to 50%.
Keywords :
Internet telephony; WiMax; quality of service; Adaptive VoIP Level Coding; G.722.2 codec; IEEE 802.16 networks; QoS; R-score improvement; Voice over IP; WiMAX; Worldwide Interoperability for Microwave Access; adaptive VoIP codec; quality of service; Binary phase shift keying; Codecs; Delay effects; Modulation coding; NIST; OFDM; Physical layer; Quality of service; Speech; WiMAX;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Communications, 2008. APCC 2008. 14th Asia-Pacific Conference on
Conference_Location :
Tokyo
Print_ISBN :
978-4-88552-232-1
Electronic_ISBN :
978-4-88552-231-4
Type :
conf
Filename :
4773796
Link To Document :
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