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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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Evaluation Methodoloy

• Testbed Configuration• Video File Statistics

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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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TxRate and Retry Limit (CBR)

Fig. Goodput vs. TxRate and Retry Limit

retry limit = 0

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TxRate and Retry Limit (Video)

Fig. Average PSNR vs. TxRate and Retry Limit

retry limit = 7

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Reservation percentage and pattern

Non-allocatable MAS

Allocatable MAS

Entire Super Frame

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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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Reservation percentage and pattern (CBR)

Fig. Throughput vs. Reservation Pattern

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Reservation percentage and pattern (CBR)

Fig. Packet Delay vs. Packet Sequence Number

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Reservation percentage and pattern (Video)

Fig. Frame jitter vs. Reservation Pattern

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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.

Thank you!