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QoS Issues for VoIP over WLAN

QoS Issues for VoIP over WLAN. 第 7 組 R91725004 嚴長青 R91725028 黃建元 R91725045 李振維 R91725046 高啟洋. Outline. Challenges Issues Service differentiation Admission control Mobility management Expected result Reference. Challenges. High requirements of delay and jitter

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QoS Issues for VoIP over WLAN

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  1. QoS Issues for VoIP over WLAN 第7組 R91725004 嚴長青 R91725028 黃建元 R91725045 李振維 R91725046 高啟洋

  2. Outline • Challenges • Issues • Service differentiation • Admission control • Mobility management • Expected result • Reference

  3. Challenges • High requirements of delay and jitter • MAC mechanism (DIFS) and high error rate of WLAN are not appropriate for these requirements • Bandwidth • The transmission of VoIP traffic is usually CBR. • MAC of WLAN does not provide QoS-guarantee service for sensitive traffic in case of heavy load.

  4. Challenges • Handover • Handover between access points can have significant impact on real-time applications. • Packet loss occurs in existing WLAN because there is no any make-before-break handover protocol. • Security • DoS、eavesdropping、interception (But these are not our concerns in this term project.)

  5. Issues (cont’) • Service differentiation • Provides differentiated service for real-time and non-real time traffic over WLAN • Admission control • Fixed available bandwidth • Let each admitted VoIP session smoothly communicate with others

  6. Issues • Mobility management • Mobile IP • Hierarchical Mobile IP • Integration of layer 2 and layer 3

  7. Expected Result • A report that consists of above three issues and related possible solutions • Our proposed solutions , if possible

  8. Reference • Issues concerning usability of 802.11 networks for real-time service transport, Kedmenec, D.; Kedmenec, V.; Gerencir, M.; Video/Image Processing and Multimedia Communications, 2003. • Selective Packet Prioritization for Wireless Voice over IP. Siemens AG, Information and Communication Mobile Networks. • "A Framework for Call Admission Control and QoS Support in Wireless Environments", INFOCOM 1999

  9. Reference • Voice Over IP: Improving the Quality Over Wireless LAN by Adopting a Booster Mechanism - An Experimental Approach Christian Hoene, Iacopo Carreras, and Adam Wolisz Proe. Of SPIE 2001 • Differentiation mechanisms for IEEE 802.11, Imad Aad and Claude Castelluccia, Infocom 2001

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