: Enabling Wireless
Sensor Network Research
Geoffrey Werner-Allen and Matt Welsh
Harvard University
werner@eecs.harvard.edu
http://motelab.eecs.harvard.edu
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
What is MoteLab?
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Web-enabled testbed for Ethernet-connected
motes
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30 MicaZ nodes distributed throughout our CS
building at Harvard
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Simple Web interface for scheduling and
programming
Automated logging to database
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All messages send to mote's serial port logged
to database
Integrated power profiling
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Power consumption of one mote logged
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
The “eMote”
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
MoteLab Design Goals
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Accelerate wireless sensor network software
design cycle
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Automate data collection
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Simplify data retreival
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Provide ubiquitous interface
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Allow global access
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Transparently arbitrate resources among
competing users
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
User Interface : Home Page
Shows information about scheduling, running, and completed
jobs, and allows data download
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
User Interface : Job Creation
We provide a number of different ways of assigning executable
to nodes
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
User Interface : Data Retrieval
After the job completes, we download collected data from the
homepage
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
Access Control
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Rolling user quotas
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decremented on job schedule
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incremented on job completion
Transparent job schedule
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users can observe greedy behavior
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allows correct scheduling of temporally-sensitive
jobs
Lab administrators have full control over
scheduling
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
Lab Partitioning
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Breaks testbed into multiple independent
chunks
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Users can select a subset of motes to
execute their job
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Suggested by Eric Fraser at UCB
At Harvard : “MD East”, “MD West”, or “MD All”
subsets of the lab
Easy to define new spatial partitions as
necessary
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
Interactive Use
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Each mote's serial port available via TCP/IP
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Allows interactive use while a job is running
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Does not interfere with database logging
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
Power Profiling
Sample data collected from node instrumented with Keithley 2701
Digital Multimeter
Continuous Mode : 250 Hz
Burst Mode : 3000 Hz
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
Connectivity Graphs
Lab connectivity information collected regularly by a standard
MoteLab job
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
MoteLab @ Harvard : Uses
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Education
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Two courses have created MoteLab-based class
assignments
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Numerous course projects have used MoteLab
Research
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MoteLab has aided in almost every sensor
network-related research project, including
CodeBlue, TOSSIM, and Volcanic Monitoring
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
Future Work
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In progress
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Scripting Interface (Kyle Jameison, Bret Hull,
MIT)
Planned
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Continue Modularization
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Integrate with other hardware platforms (e.g.,
Telos)
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Decouple access and job scheduling
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
MoteLab is OPEN
for ACCOUNTS email:
werner@eecs.harvard.edu
for SOURCE visit:
motelab.eecs.harvard.edu
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
User Interface : Job Creation
Job creation begins with naming and a description
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
User Interface : Job Creation
Jobs consist of executable files to reprogram the nodes and
class files that allow us to parse sent messages
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
User Interface : Job Creation
Power profiling is one of several job options that we support
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
User Interface : Scheduling
Here we've selected a 15 minute interval to run our job
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
User Interface : Scheduling
We've successfully scheduled our job, and the schedule page
reflects that it is waiting to be run
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
MoteLab Architecture
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University
MoteLab @ Harvard : Stats
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30 nodes over 3 floors of a large office
building
Statistics, over 16 months:
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85 users, 58 Harvard, 27 external
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820 unique jobs created
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2516 experiments run
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Average job length: 20 minutes
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Longest job : 5.5 hours
TinyOS Technology Exchange 2005, © Geoffrey Werner-Allen, Harvard University