1. QoS Issues for VoIP over WLAN
第五組
R 黃偉峰
R 呂孟庭
R 楊溫志

2. QoS Issues
Delay < 150ms
Jitter
Packet loss rate
Bandwidth

3. QoS Mechanisms for VoIP

4. QoS Mechanism in WLAN Medium Access Control scheme DCF & PCF
802.11e Hybrid Coordinator Function( HCF ) Contention free access( HCF polling ) Contention-based access( EDCF )

5. Our focus Control plane QoS Mechanisms 802.11e QoS-aware MAC protocol
Evaluate the performance of different techniques
Evaluate the possibility of combining different techniques

6. Reference
[1] Xiuzhong Chen, Chunfeng Wang, Dong Xuan, Zhongcheng Li, Yinghua Min and Wei Zhao, “Survey on QoS Management of VoIP,” in ICCNMC 2003.
[2] Xin Gang Wang, Geyong Min and John E. Mellor, “Improving VoIP Application’s Performance over WLAN Using a New Distributed Fair MAC Scheme,” in AINA 2004.