master-degree-notes/Autonomous Networking/notes/6 Internet of Things.md

IoT term is used to refer to

• the resulting globlal network of connecting smart objects
• technologies needed to realize such a vision
• applications and services leveraging such technologies

required features:

• devices hetereogeneity
• scalability
• data ubiquitous data exchange
• energy-optimized solutions

key features:

• localization and tracking (many applications require position and movement tracking)
• self-organization capabilities (support ad-hoc networks)
• semantic interoperability (standard formats for data)
• embedded security and privacy-preserving mechanism

Backscattering

• allows devices to run without battery
• only available at research level for now
• use radio frequency signals as power source
• two types
  • ambient
  • RFID

Ambient backscattering

• devices harvest power from signals available in the environment

• they use existing RF signals without requiring any additional

• Performance drawbacks

  • low data rate (about 1kbps)
    • not suitable for real-time applications that continuously exchange data
  • availability of signals
    • signal may not be available indoor or not powerful enough

RFID backscattering

• main advantage is the availability of RFID signal. Reader is always present in a RFID

Battery free smart home

• in a smart home there may be a lot of smart devices
• if every one of them has a battery, it's not good for the environment
• we can deploy an RFID reader with multiple antennas that covers all the different rooms
• of course RFID sensors can have very low capabilities, but they can run sensors!

Communication

add scheme slide

RFID tags run EPC Global Standard

• in a smart home we may want less bits dedicated to the tag id and more dedicated to the actual data
• 8 bits for ID
• 6 bits for data
• 4 for CRC

Infrastructure based wireless networks

• base stations connected to wired backbone network
• stations choses the closest base station
• Limits
  • when no infrastructure is available
  • expensive/inconvenient to setup
  • when there is no time to set it up