Lab Meeting 01162006

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Lab Meeting 01/16/2006

• Gaurav Mathur

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Contents

• Storage Project overview
• Measurement study of Storage devices
• Object Storage overview
• TinyOS Technology Exchange (TTX) 06 highlights

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Measurement Study

• Motivation
• Applications working with high data volumes
  growing
• Camera sensor networks, Acoustic, Biological
  sensor networks

What is the most energy-efficient storage
platform for sensor devices ? How does the
energy cost of storage compare to that of
computation and communication ?
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Measurement Study

• Compare MMC, NOR NAND flash technology
• Measure active sleep mode power consumption (uJ
  / byte)

Without ECC. Cost of performing ECC in software
is approx 0.026uJ/byte

• Toshiba 16MB NAND flash most energy efficient
• 21x better than Telos NOR
• 65x better than Hitachi MMC
• 407x better than Mica2 NOR
• 3x more efficient than Toshiba 128MB NAND

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Measurement Study

• Compare MMC, NOR NAND flash technology
• Measure active sleep mode power consumption

Parallel NAND flash most energy efficient More
than 200 times more efficient in comparison to
communication
Comparable to computation costs store everything
! Enables ultra-low power, almost infinite
storage (1 GB) for sensors
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Object Storage System

• Motivation
• Existing storage interfaces
• File systems - YAFFS, ELF, YAFFS2
• Stream storage and indexing MicroHash
• Other sensor application requirements
• Easy access to archived data for query processing
• Support for data consistency
• Hardware independence
• Overcome memory constraints of platforms

But sensors do not operate on files
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Object Storage System

• Storage object interface exposed to applications
  stream, stack, queue, index, array
• Implemented on NAND flash
• Support concurrent data streams
• Minimal memory footprint
• Transaction support (atomic and durable)
• Data prioritization

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TTX 2006 Highlights

• TinyOS 2.0 beta has been released
• Each sender has a private queue of depth 1
• Networking group focusing on data dissemination
  and data collection as primary interfaces
• Huge codebase compiled code less for most
  platforms, more for a couple
• Xbow acquired/ acquiring rights to manufacture
  iMote2
• iMote2 seems like a good platform for processing
• PXA 271 / 273 processor
• SDIO, GPIO, UART, I2C and other connector options
• Acquire iMote2 prototypes

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Imote2 (Top View)
LED
Basic I/O connector
Dialog PMIC
36 mm
PXA273
Crystals
Basic I/O connector
48 mm
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Imote2 (Bottom View)
Advanced I/O connector
Antenna
CC2420
Crystal
36 mm
Mini USB Connector
Advanced I/O connector
Optional SMA connector
48 mm
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TTX 2006 Highlights

• Moteiv release Tmote Invent

• Integrated Telos Sky mote
• Integrated light, temperature, acceleration, and
  sound sensors, and a rechargeable battery
• Speaker, LEDs, and User input buttons
• Customized TinyOS platform

• Chipcon TI merger means a TI MSP430 CC2420
  solution might be out soon
• Chipcon folks didnt commit, but mentioned they
  were working on this

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TTX 2006 Highlights

• Misc
• CSIRO using a custom developed platform
• Solar powered generates about 40mA. Might add
  in supercaps
• Based on Nordic radio chip range 500m
• Multiple deployments successful
• Databases / web services
• Relevance in current sensor net context ???