(FC5260) Instructor: Venkat Padmanabhan 1 What this course is and - - PowerPoint PPT Presentation

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(FC5260) Instructor: Venkat Padmanabhan 1 What this course is and - - PowerPoint PPT Presentation

Special Topics in Mobile Systems (FC5260) Instructor: Venkat Padmanabhan 1 What this course is and is not Learn about the frontiers of mobile systems research Experience research yourself by way of a mini project It is NOT about


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Special Topics in Mobile Systems (FC5260)

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Instructor: Venkat Padmanabhan

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What this course is and is not

  • Learn about the frontiers of mobile systems

research

  • Experience research yourself by way of a mini

project

  • It is NOT about getting a high grade or

boosting your GPA!

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Course Evaluation

  • Class participation: 15%
  • Written paper critiques: 15%
  • Project proposal: 15%
  • Project checkpoint: 15%
  • Final project presentation: 20%
  • Final project report: 20%

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Course Schedule

  • Monday, Aug 19: Lecture 1 + project discussion
  • Saturday, Aug 31: Lecture 2 + project proposals due
  • TBD: Lecture 3
  • TBD: Lecture 4
  • TBD: Lecture 5 + project checkpoint
  • TBD: Lecture 6
  • TBD: Lecture 7
  • TBD: Lecture 8
  • Saturday, Nov 30: Final project presentation &

report

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Mobile Systems

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What Defines a Mobile System

  • Mobile
  • Lightweight
  • Battery-powered
  • Wirelessly-connected
  • Always-on
  • Personalized
  • Sensor-rich

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SLIDE 7

Issues & Challenges

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  • Energy efficiency
  • Adaptive

communication

  • Context
  • Location
  • Privacy
  • Cloud augmentation
  • Mobile
  • Lightweight
  • Battery-powered
  • Wirelessly-connected
  • Always-on
  • Personalized
  • Sensor-rich
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General Strategies

  • Optimize the common case (e.g., connected

standby)

  • Energy proportionality (e.g., DVFS)
  • Scheduled operation (e.g., WiFi PSM)
  • Complementarity (e.g., WiFi vs. cellular)
  • Triggered operation (e.g., location change)
  • Offload (e.g., cloud offload)
  • Crowdsourcing (e.g., maps)

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Thought Experiment #1

  • Design a mobile social network service with

proximity-based alerts

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Thought Experiment #2

  • Design an energy-efficient background

transfer service

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Mini-Research Project

  • Project on some mobile systems problem
  • Defining the problem is key!
  • Would involve experimentation and

implementation

  • Documenting and presenting the work is as

important as doing it

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Some Project Suggestions

  • 1. Stabilizing mobile display for rough roads
  • 2. Energy-optimized display based on gaze tracking
  • 3. Mobile-based tracking of TV ad context
  • 4. Personalized voice commands
  • 5. Robust mobile transactions with intermittent

connectivity

  • 6. Driver scorecard
  • 7. WiFi privacy leak detection and mitigation
  • 8. User tracking using weighing scales
  • 9. Spatial meeting recorder

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#1: Stabilizing Mobile Display

  • Problem: reading for long or viewing video while on a

rough road can be tiring

  • Hypothesis: tiredness results from the relative

movement between the displayed content and the viewer’s eyes, requiring the eyes to constantly adjust

  • Idea:

– use accelerometer and front-facing camera to estimate the relative movement – adjust rendering of content to eliminate it

  • Research question:

– effectiveness – energy efficiency

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#2: Energy-Optimized Display

  • Problem: display consumes a lot of energy

even when the user is only focusing on a part

  • f it or not looking at it at all
  • Approach:

– dim display or darken the pixels based on what the user is looking at or interacting

  • Research questions:

– energy savings

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#3: TV Ad Context

  • Problem: viewing of content, including ads, on TV is

disconnected from online experience

  • Goal: bridge the two

– allow user to bookmark TV ads – profile user based on TV ads viewed

  • Approach:

– use smartphone to listen in on TV ad – match against database of ad fingerprints

  • Research questions:

– speed & accuracy – energy efficiency

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#4: Personalized Voice Commands

  • Problem: voice-based interaction is prone to

failure because of accent and language

  • Goal: enable personalized voice commands for

arbitrary actions

  • Approach:

– record macro for specified user actions – associate voice command with macro

  • Research question:

– flexibility and customization

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#5: Robust Transactions with Intermittent Connectivity

  • Problem: intermittent connectivity (e.g., for a

mobile cellular client) causes failure of multi- step network transactions

  • Idea: mask network failures from transaction
  • Approach: client-side and server-side proxies

to mask failures and keep connections alive

  • Research question:

– effectiveness

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#6: Driver Scorecard

  • Problem: bad driving abounds --- speeding, excessive

honking, violation of traffic rules

  • Idea: used smartphone to create a driving scorecard
  • Approach:

– use sensors to measure different facets of driving – crowdsource measurements to detect anomalies – create a competitive game

  • Research questions:

– incentives – accuracy – energy efficiency

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#7: WiFi Privacy Leakage

  • Problem: WiFi transmisions leak private info

by allowing a user to be tracked

  • Idea: obfuscate the WiFi MAC address
  • Approach:

– set a random MAC address for probe requests – switch between MAC addresses in an unlinkable way

  • Research question:

– effectiveness

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#8: User Tracking using Weight

  • Problem: counting and tracking users is key to

physical analytics

  • Idea: leverage the constancy of a user’s weight to

track the user

  • Approach:

– install (hidden) weighing scales at key locations – count people going in and out of a space

  • Research questions:

– reliability of weight measurement for a walking user

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#9: Spatial Meeting Recorder

  • Problem: meeting recording is typically only indexed by

time

  • Goal: enable indexing by speaker, and more, by

annotating recording with relative spatial positions of speakers

  • Approach:

– use acoustic ranging to establish relative positions of users’ phones – establish positions of speakers relative to the phones

  • Research questions:

– accuracy – energy efficiency

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Project Proposal

  • Due Saturday, Aug 31
  • One-page max, single column, 10 pt font
  • What problem is being solved
  • Why is it important
  • What is the proposed approach
  • Expected deliverable
  • Rough plan

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Next Lecture: Energy

  • Papers to be critiqued:

– “An Analysis of Power Consumption in a Smartphone”, Usenix ATC 2010 – “Fine Grained Energy Accounting on Smartphones with Eprof”, EuroSys 2012

  • Other papers to read:

– “Carat: Collaborative Energy Debugging for Mobile Devices”, Usenix HotDep 2012 – “Who Killed My Battery: Analyzing Mobile Browser Energy Consumption”, WWW 2012

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Paper Critiques

  • One-page max, single column, 10 pt font
  • Summarize the paper in your own words
  • Call out key contributions
  • Identify shortcomings
  • Suggest improvements
  • Note: would require reading more than the

paper!

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