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Turducken : Hierarchical Power Management for Mobile Devices. Jacob Sorber , Nilanjan Banerjee , Mark Corner, Sami Rollins. Presentation prepared by: Kip Coonley. University of Massachusetts, Amherst. - PowerPoint PPT Presentation
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Turducken: Hierarchical Power
Management for Mobile DevicesJacob Sorber, Nilanjan Banerjee,
Mark Corner, Sami Rollins
University of Massachusetts, Amherst
Presentation prepared by: Kip Coonley
Paper appears in “Proceedings of the Third International Conference on Mobile Systems, Applications, and Services” (MobiSys 05), Seattle, WA, USA, June, 2005
Additional figures from www.cs.dartmouth.edu/~sorber/slides/mobisys2005slides.ppt
Key issue: Battery Lifetime vs. Mobility
Scenarios and photos care of Nilanjan Banerjee www.csce.uark.edu/~nilanb/
Scenario 2 Scenario 3
Key question: Which device to use?
laptop phone Mote
Scenario 1
40W
2W
0.04WSensor
PDA
Laptop
Simple computationand storage
Download Web Pages
Very complex computation
Send/RecvMail
Tasks requiringlarge memory or storage space
Pow
er N
eeds
Choosing the right device for the job
Wake-On-Wireless [Shih, et al]Low-power radio receives wakeup messagesRequires in-network supportFocus on when to wake up
Possible Solutions (Related Work)
WiFi Power Save Mode (PSM)
Local Availability of dataStaleness issue
Battery technologyEnergy scavenging
Wireless optimizations [Anand, et al], Disk Spindown [Helmbold, et al], Multiple radios [Pering, et al], Multiple processor cores [Mayo & Ranganathan]none provide orders-of-magnitude scaling of
power
A New Approach: Turducken – 3 devices in 1
WiFi detector
Mica2 Mote
PDA
Laptop
Example: Mote checks for a network, PDA checks for mail server,Laptop remains asleep until user reads the mail
• Integrate multiple independent platforms
• Pass control between tiers• Suspend unneeded tiers
The Idea: Hierarchical Power Management
Reducible Power – Power that can be eliminatedReducible vs. Non-Reducible Power
Non-reducible Power – Required for computation
• LCD Screen, Wireless power, Caching
• Power supply, On-board oscillators, Memory, I/O buses, Voltage & Current regulation
• Time SynchronizationCan be completely performed by the moteLowest tier periodically synchronizes with remote time
server• Web Prefetching
More complicated application which requires at least PDAMote detects wireless networksPDA periodically fetches updates to frequently accessed
pages• E-Mail
Involves user interactionBoth incoming and outgoing updatesLaptop accesses mail via proxy on the PDA
3 Applications
• Laptop• Laptop+Mote• Laptop+PDA+Mote
3 ConfigurationsA Tiered Approach
PDALaptop MoteUSB RS-232
Wake
Note on Methodology: Time dilation used to extrapolate data
• Power Draw Comparisons of Turducken Tiers
• Wakeup Interval vs. Lifetime for Integrated Turducken System
• Availability of Wireless Networks and its impact on the Turducken System
3 Experiments
Laptop Laptop+Mote
Full Turducken
Power-By-Tier
Wake Synchronization Time of Device
Time SynchronizationMote is the right device for the jobLaptop & PDA always suspended
Wake Synchronization Time of Device
Web Caching5MB storage = 15 websites cached
For always-on operation, Turducken lasts up to 10 times longerWaking every 6 minutes, Turducken lasts 3 times longer
Wake Synchronization Time of Device
E-MailLaptop wakes 2 min every hr, 4MB of mail stored
Due to laptop user input, overall system lifetimes much lessFor waking every 6 minutes, Turducken lasts 1.5 times longer
Availability of Wireless Network(Web caching only, 12 minute wake interval preset)
Probability of WiFi
Life
tim
e (h
ours
)
With no network, mote prevents laptop from wakingTurducken performs well over a variety of connectivity patterns
Conclusions & Thoughts• Turducken extends laptop lifetime up to
10x (Always-on)!• Where Turducken Wins - Laptop on > 17
min/hr
• Hierachical Power Management & Reducible vs. Non-Reducible Power
• Sleep/Wake power costs – this work averages
• Device portability/weight integration of tiers
• Device reliability with integration of tiers
Turducken: Hierarchical Power
Management for Mobile DevicesJacob Sorber, Nilanjan Banerjee,
Mark Corner, Sami Rollins
Paper appears in “Proceedings of the Third International Conference on Mobile Systems, Applications, and Services” (MobiSys 05), Seattle, WA, USA, June, 2005
One more experiment: Reachability of Wireless Network(Web caching only, 12 minute wake interval preset, always available)
Similar results to Availability of WiFi except…Mote cannot access WiFi -only detect it - PDA must work more