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Realization of an IEEE 802.11g VoWLAN Terminal with Support of Adaptable Power Save and QoS During a Call  

Kwon, Sung-Su (LG-NORTEL 연구소 BCS 개발실)
Lee, Jong-Chul (광운대학교 전파공학과)
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.31, no.10A, 2006 , pp. 1003-1013 More about this Journal
Abstract
There is a serious problem in an 802.11g VoWLAN (Voice over Wireless LAN) terminal that talk time is less than 30% compared with an 802.11b terminal. It is almost impossible to achieve talk time level of the 802.11b MAC transmission method because IEEE 802.11g uses OFDM modulation, which is a kind of multi-carrier method and OFDM transmission speed is 54 Mbps faster than normal modulation. In this paper, a new concept of a Holdover time as a power saving method during a call with 802.11g terminal is suggested for the first time. Increase in the number of engaged terminals as a result of holdover time causes to QoS problem because of the increase in the number of back-off and then contention window. In this paper, to solve the QoS problem, a new approach is suggested such that when in down lint the sequence number of 802.11 G.711 is analyzed in the MAC of the terminal and then the Hold over time depending on loss rate is changed. Also, consumption of an electric current of 802.11b/g and MAC parameter's performance due to busy traffic caused by increase in the number of terminal are analyzed and then real data using VQT and Airopeek are analyzed.
Keywords
VOWIAN; IEEE802.11b/g; OFDM; QoS; back-off; Holdover time; MAC;
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