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Evaluating Video Streaming over UWB Wireless Networks
Rukhsana Ruby
University of Victoria
Joint work with Yangyang Liu, and Jianping Pan
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Outline
• Existing WLAN Technologies
• UWB Overview
• Evaluation Methodology
• Performance Analysis
• Performance Results
• Discussion
• Future Research
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Existing WLAN Technologies
• Support low data rate (11 to 54 Mbps) 802.11b and 802.11a/g (Achieve less than 50% of actual data rate)
• Work in 2.4 and 5 Ghz frequency band. avg throughput of 802.11g 10 Mbps
• Contention – based MAC
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UWB Overview• UWB is a radio technology• UWB is regarded as the best technology
for the high-speed wireless PAN. Why?High speed at short range
o Up to 480Mb/s currently. Ultimately support the speed at Gbit/s.
o In the range of 10 meters.
Radio spectrum: 3.1 to 10.6 GHz (very large).Low energy consumption level
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UWB PHY
• DS-UWB 28, 55, 110, 220, 500, 660, 1000, 1320 Mbps
• MB-OFDM MBOA: Multi-band OFDM Alliance; WiMedia
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UWB MAC• Time is divided into super frames.
256 MAS (Each MAS is 256us)• Beacon Period (First 32 MAS)
Contract and Expand able• Data Period
DRP and PCA (Like 802.11e)• Acknowledgement Policy
No, Block and Immediate Acknowledgement
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Testbed Configuration
• uw1 and uw2ui1 and ui2 for control accessTzero ZeroWire Mini PCI 700
Revision B card with Dual antenna
• Tea cans on antennaRSSI -73 dBm
• No PCA, only DRPCollision if same MAS is
reserved by uw1 and uw2
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Video File Statistics
• 4 MPEG-4 AVC video streamsResolution
1920*1080, refresh rate 24 frames/sec
Average frame size 21.152 kilo bytes
Average data rate is around 4.186 Mbps
Fig. Frame size vs. Frame Sequence Number
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Performance Analysis
• Duration of the entire PLCP packet:
• Maximum number of PLCP packets can go through in the reservation of n MAS is:
0.3125 us18 or 30 symbols
12 symbols
UDP pkt length
12 us
10 us
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Performance Results
• TxRate and Retry Limit (CBR and VBR)
• Reservation percentage and pattern (CBR and VBR)
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Reservation percentage and pattern
Un-reserved MASReserved MAS
Sample of 16 MAS for reservation pattern index 1 & 3
32-alternative5
64-alternative6
16-alternative4
8-alternative3
4-alternative2
2-alternative1
Reservation Pattern
Reservation Index
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Discussion
• Tradeoff between TxRate and Retry Limit
• Throughput, Latency tradeoff between clustered and scattered reservation.
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Future Research
• Model UWB MAC
• Centralized algorithm for MAS reservation taking account of service interval.
• Distributed algorithm in beacon period for MAS reservation.