Building Blocks for the Internet of Things @ Home

Building Blocks of The Internet of Things

@ Home

Wednesday, 17 July, 13

IMO

David Janes@dpjanes

davidjanes@davidjanes.comhttp://imadeit.davidjanes.com/

July 2013

Wednesday, 17 July, 13

AKA “The Intranet of Things”

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Important!

The Internet of Machinesis just

The Internet with Machines!

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The Building Blocks of the Internet @ Home?• Wi-Fi

• TCP/IP

• URLs / DNS

• HTTP

• HTML / JS / CSS

• JSON / XML

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The same tech enables The Intranet of Things

... more or less ...

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What are the issues?

• Communication

• Discovery

• Control

• Interoperability

• Security

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Communications

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Communications

• How will things talk to things?

• How will we talk to things?

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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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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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BLE purpose

• for small sensors and devices

• for personal area networks

• for health stuff ... scales, heart-rate monitors, etc.

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BLE use

• Think of it as “invisible wires”

• Will be controlled...

• directly by mobile devices

• indirectly through hubs

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Discovery

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“Google for my home”

• find what’s available...

• ... and what can I do with it?

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Bonjour

• Lightweight Service Discovery

• Standard needed for specifying how to find IoT services / APIs

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Control

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APIs

• IoT devices are controlled by APIs

• URLs ... from Bonjour Discovery

• HTTP

• JSON

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REST

• URLs describe things ... not actions

• /api/light-2 ✓

• /api/light-2/off ✗

• Stateless

• ... lots of other stuff ...

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HATEOAS

• Always explicitly use URLs ... not numbers or special codes

• “devices” : [ “/api/light-1”, “/api/light-2” ] ✓

• “devices” : [ 1, 2 ] ✗

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JSON

GET /api/devices{ "devices" : [ "/api/light-1", "/api/light-2" ]}

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JSON

GET /api/light-1{ "on" : true, "brightness" : 0.5, "color" : "#FFFFFF"}

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JSON

PUT /api/light-1{ "on" : false}

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Interoperability

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Can...

• devices easily talk to each other?

• devices be controlled from one UI?

• “novel” devices be effortlessly introduced?

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Standards?

• Fine grained / line level ... not on

• Everyone always does their own thing

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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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The Semantic Web

• A kind of wide-open database, use what you need, infinitely extendable

• Everything described by URLs

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schema.org

• Vocabulary for describing things and products (and more)

• e.g. this is a Toshiba 42” Flatscreen TV

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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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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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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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Security

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We Can’t...

• Hide the devices / APIs

• Make everyone log into every device

• Get this wrong!

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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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Wide open

• Sorry, I’ve got nothing

• This can’t be half-baked

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Device Limitations

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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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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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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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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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Get in touch!

David Janes@dpjanes

davidjanes@davidjanes.comhttp://imadeit.davidjanes.com/

Wednesday, 17 July, 13