The document outlines the foundational elements of the Internet of Things (IoT) at home, focusing on key technologies such as Wi-Fi, TCP/IP, and communication protocols like Bluetooth Low Energy. It discusses challenges including communication, discovery, control, interoperability, and security, while also emphasizing the need for standards and semantic web integration for better device interaction. The author calls for a holistic approach to IoT security and device functionality to create a seamless connected home experience.

1. Building Blocks of
The Internet of Things
@ Home
Wednesday, 17 July, 13

2. IMO
David Janes
@dpjanes
davidjanes@davidjanes.com
http://imadeit.davidjanes.com/
July 2013
Wednesday, 17 July, 13

3. AKA “The Intranet of
Things”
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4. Important!
The Internet of Machines
is just
The Internet with Machines!
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5. The Building Blocks of
the Internet @ Home?
• Wi-Fi
• TCP/IP
• URLs / DNS
• HTTP
• HTML / JS / CSS
• JSON / XML
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6. The same tech enables
The Intranet of Things
... more or less ...
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7. What are the issues?
• Communication
• Discovery
• Control
• Interoperability
• Security
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8. Communications
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9. Communications
• How will things talk to things?
• How will we talk to things?
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10. Protocols
• Wi-Fi
• TCP/IP
• HTTP
• JSON / XML ... for things to things
• HTML ... for us to things
• Bluetooth Low Energy (special case)
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11. Bluetooth Low Energy
• Ships in all modern iOS devices
• Ships in many new Androids
• 30m range (50m claimed)
• Coin-cell-sized devices
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12. BLE purpose
• for small sensors and devices
• for personal area networks
• for health stuff ... scales, heart-rate
monitors, etc.
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13. BLE use
• Think of it as “invisible wires”
• Will be controlled...
• directly by mobile devices
• indirectly through hubs
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14. Discovery
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15. “Google for my home”
• find what’s available...
• ... and what can I do with it?
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16. Bonjour
• Lightweight Service Discovery
• Standard needed for specifying how to find
IoT services / APIs
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17. Control
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18. APIs
• IoT devices are controlled by APIs
• URLs ... from Bonjour Discovery
• HTTP
• JSON
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19. REST
• URLs describe things ... not actions
• /api/light-2 ✓
• /api/light-2/off ✗
• Stateless
• ... lots of other stuff ...
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20. HATEOAS
• Always explicitly use URLs ... not numbers
or special codes
• “devices” : [ “/api/light-1”,“/api/light-2” ] ✓
• “devices” : [ 1, 2 ] ✗
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21. JSON
GET /api/devices
{
"devices" : [
"/api/light-1",
"/api/light-2"
]
}
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22. JSON
GET /api/light-1
{
"on" : true,
"brightness" : 0.5,
"color" : "#FFFFFF"
}
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23. JSON
PUT /api/light-1
{
"on" : false
}
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24. Interoperability
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25. Can...
• devices easily talk to each other?
• devices be controlled from one UI?
• “novel” devices be effortlessly introduced?
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26. Standards?
• Fine grained / line level ... not on
• Everyone always does their own thing
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27. But we’re almost there!
• Our standards stack gets us a long way
• i.e.Wi-Fi, HTTP, REST, HATEOAS, JSON
• We just need one last bit of translation
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28. The Semantic Web
• A kind of wide-open database, use what
you need, infinitely extendable
• Everything described by URLs
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29. schema.org
• Vocabulary for describing things and
products (and more)
• e.g. this is aToshiba 42” FlatscreenTV
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30. iotdb.org
• A work in progress!
• Vocabulary for describing how to control
IoT things
• e.g. this is a light, this can be turned on and
off, this has a brightness control, this has a
color
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31. JSON-LD
• Links JSON documents to the Semantic
Web
• Too clumsy / difficult for the IoT
• Developers are not likely to adopt ...
• ... but the technique is perfect
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32. The Rosetta Stone
• Add a single definition term to APIs
{
"@iot" : "/definitions/light",
"on" : true,
"brightness" : 0.5,
"color" : "#FFFFFF"
}
• Defines every term in the API semantically
with well-known definitions
• Another work in progress!
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33. Security
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34. We Can’t...
• Hide the devices / APIs
• Make everyone log into every device
• Get this wrong!
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35. Considerations
• Some attributes can be read by everyone
but only set by a few ... e.g. temperature
• Current implementations are bad
• AirPlay: wide open
• UPnP: broken
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36. Wide open
• Sorry, I’ve got nothing
• This can’t be half-baked
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37. Device Limitations
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38. Not that smart
• We need information outside the device
• e.g. Belkin WeMo: I can be on, I can be off
• There’s so much more we need to know!
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39. What is it really?
• Consider the WeMo
• connected to a table lamp
• connected to a space heater
• It doesn’t know!
• Same interface, effectively / collectively a
very different device
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40. Where is it?
• Is it in the kitchen? in the living room?
• Both? ... e.g. a door open sensor
• Many? ... e.g. a HVAC subsystem
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41. Wide open
• Assume there’s data that needs to be
“outside” the device
• But we don’t want to “go to the Internet”
to control our house!
• Open problem
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42. Get in touch!
David Janes
@dpjanes
davidjanes@davidjanes.com
http://imadeit.davidjanes.com/
Wednesday, 17 July, 13