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Overheads in Data Stream Over WLAN. Tan Pek Yew, Jun Hirano & Takashi Aramaki (Panasonic). Content. Definition of Data Stream in .11 WLAN Burst Ack Transmission in TXOP in .11e Header Information Bit Rates in TXOP Numerical Results Conclusions. Traffic Stream - Definition.
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Overheads in Data Stream Over WLAN Tan Pek Yew, Jun Hirano & Takashi Aramaki (Panasonic) Tan Pek-Yew, Panasonic
Content • Definition of Data Stream in .11 WLAN • Burst Ack Transmission in TXOP in .11e • Header Information Bit Rates in TXOP • Numerical Results • Conclusions Tan Pek-Yew, Panasonic
Traffic Stream - Definition Based on IEEE802.11e Draft 3.0 A traffic stream is a set of MSDUs to be delivered subject to the QoS parameter values provided to the MAC in a particular traffic specification (TSPEC) Tan Pek-Yew, Panasonic
Burst Transmission in TXOP(not Fragmented) Based on 54 Mbps PHY Full Header with Payload (2312 bytes) = 368 usec Data Packet Header Address Fields = 4 usec % for Address Fields = 4*(10+3)/4028 = 1.29% TXOP = 3968 uS Burst Data = 10 packets BurstAckReq(24uS) BurstAck(44uS) Burst Data Burst Data Burst Data(368uS) CF POLL(44uS) CF POLL Burst Data SIF(16uS) SIF SIF SIF SIF SIF SIF Tan Pek-Yew, Panasonic
Burst Transmission in TXOP (Fragmented) TXOP = 3712 uS Burst Data = 5 packets BurstAckReq(24uS) BurstAck(44uS) Burst Data Burst Data Burst Data(704uS) CF POLL(44uS) CF POLL Burst Data SIF(16uS) SIF SIF SIF SIF SIF SIF Fragment to 9 MPDUs Payload(1) (256 bytes) H Payload(9) (264 bytes) H SIF Based on 54 Mbps PHY Full Header with Payload (256-264 bytes) = 64 usec Header Address Fields Overhead = 4 usec % for Address Fields = 4*((5*9)+3)/3772 = 5.09% Tan Pek-Yew, Panasonic
Numerical Results Assumptions • Same PHY overheads as data rates increases • Worst Case Scenarios Encountered – Fragmented Packets Tan Pek-Yew, Panasonic
Conclusions • To Achieve High Throughput • Reduction of irrelevant header information • Substantial data rates can be saved from header information • Proposed that High Throughput and Future version of WNG to look into • irrelevant information be removed for data packets from one traffic stream Tan Pek-Yew, Panasonic