MOVi: Mobile Opportunistic Videoondemand

1
MOVi Mobile Opportunistic Video-on-demand
IEEE PERCOM 2008
Hayoung Yoon, JongWon Kim, Feiselia Tan, and
Robert Hsieh

• 18th, Mar., 2008
• Ph.D candidate
• Hayoung Yoon
• hyyoon_at_nm.gist.ac.kr

Networked Media Laboratory Dept. of Information
Communications Gwangju Institute of Science
Technology
National ICT Australia University of New
South Wales
Deutsche Telekom Laboratories
2
Agenda

• Background
• MOVi Architecture
• Inter-BSS Direct Link-setup
• MOVi Scheduling
• Simulation Results
• Conclusion

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Background

• Download-and-play style multimedia P2P file
  dissemination schemes have proposed
  BlueT_at_percom2007
• We propose P2P VoD streaming in mobile wireless
  networks
• Opportunistic contact between mobile nodes
• Direct WiFi comm.
• Enlarge System capacity
• Provide QoS

Pervasive Computing
Personalized Internet Services
File Sharing Dissemination Services
WBAN / WPAN / WLAN Tech.
Location-aware Services
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Conventional VoD vs MOVi
DR PR
DNR DSR PR
1. Better Channel Quality 2. Lower Power
Consumption 3. Higher data-rate
1. System capacity increased 2. Server load
deceased
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MOVi Architecture
Video Contents
MOVi Server

• Assumptions
• Mobile WiFi users
• APs in infrastructure mode
• No multi-hop connections
• Segmented Contents
• P2P approach Use client cache!
• Like Bitorrent direct p2p comm.
• Centralized controls and distributed
  communications
• Challenges
• Maximize resource utilization
• Direct Peer-to-Peer Comm.
• Minimize QoS degradation
• Scheduling

- Wired Networks -
- Wireless Access Networks -
- Mobile Opportunistic Networks -
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Direct Comm. DLS in IEEE 802.11e

• DLS (direct link setup) is optional functionality
  in IEEE 802.11e STD
• Special AP is required
• AP resolves control and relay
• Slow adaptation of DLS in real world
• Can not initiate DL (direct-link) over different
  BSS (basic subset)

Special AP
STA
STA
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Inter-BSS Direct Link Setup

• We propose iDLS that removes BSS dependency
  initiating DL through application-layer
  end-to-end signaling
• Contribution
• Design of iDLS
• Can initiate DL over different domain of BSSs
• Does not require special hardware support
• Implementation and evaluation over real-testbed
• MADWiFi and normal AP

FA
FA
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Scheduling Considerations

• Scheduling at MOVi Server?
• Select which pairs of MOVi Clients for P2P Comm.
• Select MOVi Clients download from downlink
  (AP-path)
• Can we minimize the playout quality degradation
• Minimize buffer underflow
• Remaining-buffering time-based scheduling

MOVi Server
Longest Playout buffer
Second Shortest Playout buffer
Shortest Playout buffer
CONTACT Range
need to download from
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MS Scheduler Design (2)

• Is making multiple number of simultaneous P2P
  sessions beneficial?
• No, it is not resilient to the mobility
• Some sessions share interference range
  increasing session duration
• We schedule P2P sessions to achieve burst P2P
  communications

MOVi Server
need
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Simulation Configurations

• Topology
• 8APs (all APs are connected to MS through wired
  line)
• 1050 MCs
• Mobility Trace from Crawdad dataset Kim_at_INFOCOM
  2006
• PHY
• Set Same Freq. for all APs
• IEEE 802.11a (8 different bit-rate)
• ARF (Auto-rate Fallback)
• MAC
• EDCA (high priority for controls and the low for
  data TX)
• APP
• Request rate, filesize, video playout rate is
  from YouTube measurement Youtube_at_MOBISYS

1km
1km
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What to compare?

• Compare the performance of CVoD (Conventional
  VoD) and MOVi
• QoS variation w.r.t the number of users
• Capacity w.r.t the buffering time
• Number of users meet target QoS-level
• Power consumption for communication

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Performance Metric

• Metric for video quality
• Playout continuity Index

• Expressed over (-inf,1)
• The higher the better quality
• PCI 0.95 is normally regarded as target
  performance

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Simulation Results
Play Continuity Index MOVi and CVoD Performance
Comparison
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Simulation Results
of MCs MOVi and CVoD Performance Comparison
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Simulation Results
PHY-rate Distribution over TX/RX packets MOVi
and CVoD Performance Comparison
54Mbps
48Mbps
54Mbps
36Mbps
48Mbps
36Mbps
24Mbps
24Mbps
MOVi
CVOD
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Simulation Results
Battery Consumption for TX packets MOVi and
CVoD Performance Comparison
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Simulation Results
Battery Consumption for RX packets MOVi and
CVoD Performance Comparison
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Simulation Results
Battery Consumption for RXTX packets MOVi and
CVoD Performance Comparison
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Conclusion

• MOVi provides P2P-based VoD services in IEEE
  802.11 mobile networks
• Playout quality and number of users MOVi can
  provide is roughly 200 of what CVoD can
• Better wireless channel utilization through
  direct peer-to-peer comm.
• Maintain battery consumption rate
• Validate in real testbed (please see the paper)
• We are now working on extending MOVi in the
  multi-channel environment

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Experiment Setup

• Implement MOVi using MADWiFi and VLC on Linux
• 10 times of iterations and get average PCI
  performance

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Experiment Results
Sorted MOVi and CVoD PCI Performance Comparison
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Experiment Results
Experiment and Simulation Validation
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Appendix VoD issues

• Video On-Demand (VoD) provides highly flexible
  streaming service to end-users
• Known issues in VoD service are
• Efficiency
• Multiple copies
• Scalability
• Centralized design
• Reliability
• No perfect transport protocol

Contents
T1
T2
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Appendix Scalability Issues in VoD Service
main Server

• System
• Distributed Servers
• A lot of idea in reducing workload at the server
• Bandwidth
• Too much workload in Core network
• Caching Caching_at_ICN02
• CDN Utube_at_Mobisys07
• P2P Approaches Coolstreaming P2cast

Server
Server
CDN
CDN
T1
T2
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Appendix VoD in Wireless Networks

• Access networks are infrastructure wireless
  network
• WCore WAccess
• P2P strategy is not good idea
• Double resource consumption problem
• E2E throughput degradations due to multi-hop
  forwarding
• CDN is limited
• Relatively small bandwidth of wireless networks
• Need a novel way to enhance the utilization of
  wireless network regarding VoD application
  characteristics!