1 A Multimedia Architecture for 802.11b network Berthou, P.; Gayraud, T.; Alphand, O.; Prudhommeaux, C.; Diaz, M.; Wireless Communications and Networking,

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A Multimedia Architecture A Multimedia Architecture for 802.11b networkfor 802.11b network

Berthou, P.; Gayraud, T.; Alphand, O.; Prudhommeaux, C.; Diaz, M.;Berthou, P.; Gayraud, T.; Alphand, O.; Prudhommeaux, C.; Diaz, M.;

Wireless Communications and Networking, 2003. WCNC 2003. 200Wireless Communications and Networking, 2003. WCNC 2003. 2003 IEEE , Volume: 3 , 16-20 March 2003 3 IEEE , Volume: 3 , 16-20 March 2003

Page(s): 1742 -1747Page(s): 1742 -1747

2003.11.19 NCNU CSIE MCL network group, Group Meeting2003.11.19 NCNU CSIE MCL network group, Group Meeting

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OutlineOutline

IntroductionIntroduction

Multimedia Communication in 802.11 Multimedia Communication in 802.11

Wireless NetworksWireless Networks

A Multimedia Architecture For 802.11bA Multimedia Architecture For 802.11b

Performance EvaluationPerformance Evaluation

ConclusionConclusion

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Multimedia Communication in Multimedia Communication in 802.11 Wireless Networks802.11 Wireless Networks

Multimedia communication QoS requiremeMultimedia communication QoS requirementsnts Quality of service in 802.11b networksQuality of service in 802.11b networks

(1) Dynamic Rate Shifting(1) Dynamic Rate Shifting (2) A difficult cohabitation btw low and(2) A difficult cohabitation btw low and high rateshigh rates (3) 802.11 drawbacks for multimedia(3) 802.11 drawbacks for multimedia communicationcommunication

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55

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77

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99

1010

i.e. 0.848 Mbps/user for delivering the same amount of data (1534 bytes)

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A Multimedia Architecture For A Multimedia Architecture For 802.11b802.11b

Disabling DRS in multimedia contextDisabling DRS in multimedia context

Performance Enhancing Proxy to restore QPerformance Enhancing Proxy to restore QoSoS

A strategic locationA strategic location

LimitationLimitation

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Performance EvaluationPerformance Evaluation

testbed: testbed: 11 Mbps 802.11 WLAN + wire WAN11 Mbps 802.11 WLAN + wire WAN

network delay:network delay: WLAN: 10ms , WAN: 100msWLAN: 10ms , WAN: 100ms

every 10s, reliability decreased every 10s, reliability decreased (BER:0(BER:0 10 10-4-4))

TCP throughput:TCP throughput: # delivered packets /s# delivered packets /s

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ConclusionConclusion

The 802.11b dynamic rate shifting mechaniThe 802.11b dynamic rate shifting mechanism is proposed to be disabled and replaced sm is proposed to be disabled and replaced by a Performance Enhancing Proxy at the by a Performance Enhancing Proxy at the wireless network edge.wireless network edge.

This multimedia architecture could be a cheThis multimedia architecture could be a cheap solution for the already deployed 802.11ap solution for the already deployed 802.11b networks.b networks.