59 lines
No EOL
2 KiB
Markdown
59 lines
No EOL
2 KiB
Markdown
IoT term is used to refer to
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- the resulting globlal network of connecting smart objects
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- technologies needed to realize such a vision
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- applications and services leveraging such technologies
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required features:
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- devices hetereogeneity
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- scalability
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- data ubiquitous data exchange
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- energy-optimized solutions
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key features:
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- localization and tracking (many applications require position and movement tracking)
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- self-organization capabilities (support ad-hoc networks)
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- semantic interoperability (standard formats for data)
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- embedded security and privacy-preserving mechanism
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#### Backscattering
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- allows devices to run without battery
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- only available at research level for now
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- use radio frequency signals as power source
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- two types
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- ambient
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- RFID
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##### Ambient backscattering
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- devices harvest power from signals available in the environment
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- they use existing RF signals without requiring any additional
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- Performance drawbacks
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- low data rate (about 1kbps)
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- not suitable for real-time applications that continuously exchange data
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- availability of signals
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- signal may not be available indoor or not powerful enough
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##### RFID backscattering
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- main advantage is the availability of RFID signal. Reader is always present in a RFID
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##### Battery free smart home
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- in a smart home there may be a lot of smart devices
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- if every one of them has a battery, it's not good for the environment
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- we can deploy an RFID reader with multiple antennas that covers all the different rooms
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- of course RFID sensors can have very low capabilities, but they can run sensors!
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### Communication
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add scheme slide
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RFID tags run EPC Global Standard
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- in a smart home we may want less bits dedicated to the tag id and more dedicated to the actual data
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- 8 bits for ID
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- 6 bits for data
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- 4 for CRC
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### Infrastructure based wireless networks
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- base stations connected to wired backbone network
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- stations choses the closest base station
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- Limits
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- when no infrastructure is available
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- expensive/inconvenient to setup
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- when there is no time to set it up |