Technologies Under the Surface of Ubiquitous Computing : Wireless Sensor Networks

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

• Ken Mikelinich
• University of New Hampshire

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

• Opportunities
• Emerging systems engineering of many
  technologies
• Wireless technologies
• Software technologies
• Hardware technologies
• Embedded Designs
• Power technologies
• Constraint based engineering
• New problems and applications
• Security
• Multi-discipline sensor technology
• Low cost to entry
• Great capstone curriculum for engineering
  students

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

• Goals
• Introduce Wireless Sensor Networks (WSN) systems
• Identify key technologies prevalent in WSN
• Relate these technologies as foundational
  technologies for UbiComp systems.

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

• Introduction
• What are WSN systems?
• Wireless Sensor Networks (WSN) are networks that
  consist of small, independent, collaborating
  wireless devices (nodes) that are cost-effective
  and intelligent solutions for various
  applications in automation, healthcare,
  environmental monitoring, safety, and security
• Vendors include CrossBow, Sun, Jennic, Ember,
  Zensys, Sensinode, Meshnetics

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

• Technologies
• Power Technologies
• Battery
• Today Li Ion and Nickel Metal Hydride and Nickel
  Cadmium
• Tomorrow Nano-structures 10 times the storage
  capacity and w/o structural damages to silicon.
• Generation
• Scavenging via vibrations using MEMs w/
  piezoelectric (used today w/ tire pressure
  gauges)
• Photosynthetic electrochemical cells (PECs).
• Multiple Exciton Generation (MEG) Quantum dot
  solar
• CIGS thin film solar
• Management
• Sleep cycles for various nodes or components
  (limit routes and antenna)
• Network Architecture (routing, QoS)
• Specialized power management APIs
• CPU thread and process prioritizations

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

• Network Technologies
• Satellite, WLAN, Mobile and WPAN
• Wireless Personal Area Network (WPAN)
• What are they? Low power, close proximity (10m
  or less), wireless networks
• Zigbee, Zwave, Bluetooth, and Ultra Wide Band
  (UWB)
• Zigbee
• Open technology based on IEEE 802.15.4
• 802.15.4 provides the PHY and Sub-layer MAC
  specifications
• Zigbee provides Networking and Applications
  Layers
• RF at 2.45GHz, 915MHz, 868MHz
• New challenges
• Time synchronization
• Self organization
• Dropped channel links, obstructions ? poor QoS
  and noisy channels
• Power limitations and security

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

• Security Technology
• Access is easy, usually deployed in public places
• Authentication
• Public Key Cryptography (PKC) (asymmetric key)
• RSA, Elliptical Curve Cryptology (ECC)
• Dual key more computationally intensive power
  usage, calculation time and real-estate
• Can handle digital signatures and non-repudiation
• ECC about the best today (small key size, and
  strong security)
• Encryption
• Symmetric key
• Data Encryption Standard (DES), Advance
  Encryption Standard (AES)
• Fast less intensive, smaller key sizes
• Key management does not scale well.
• Done both at application and MAC layers

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

• Conclusion
• Systems can be very small yet complex
• Great platform to tie in engineering principles
• Many new applications to be explored
• Low costs to entry.

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Technologies Under the Surface of Ubiquitous
Computing Wireless Sensor Networks

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