The Internet; the Things; the Internet of Things

I've been struggling recently to define something very fundamental: what is it we want to accomplish with the Internet of Things. And to answer that, I think we have to look back several decades and answer this question: "What is the Internet".

Wikipedia gives us a fairly clear definition:

The Internet is the global system of interconnected computer networks that use the Internet protocol suite (TCP/IP) to link billions of devices worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and peer-to-peer networks for file sharing.

So at the core the Internet is TCP/IP connecting TCP/IP networks. And although there's lots of interesting applications running on top of the Internet - think Netflix or Skype - the real killer application of the Internet is The Web: HTML and HTTP.

So looking at the Internet, we see this stack:

• HTML
• HTTP
• TCP
• IP

or from a programmer using services on the network, this:

• APIs
• HTTP
• TCP
• IP

Of course, there was lots of other things we could have been using. DECNet, XNS, SNA, X.25, NAPLPS…. Why aren't these things "the Internet" too? Well, because they're not: the Internet is us agreeing to us these specific open standards.

IETF and other standard groups are redefining some of these layers in the stack, for example substituting CoAP for HTTP, or IPv6 for IPv4. Conceptually though they're sorta the same thing. Not quite, but good enough. I'm glad there's people thinking about it, but it's not my interest right now.

My contention is that this stack, with or without the substitutions, is sufficient to define the Internet of Things. We do not need to be defining fundamentally new protocols at these layers.

Below this of course there's lots of stuff going on, but who cares? Are you actually that interested in the Link Layer and the Media Layer? They'll sort it out. I have WiFi, I have some sort of DSL, I have wired Ethernet. All the stuff on top works without me thinking about that stuff.

So now that we got the "Internet" part sorted out, what about the "Things"? The "Internet of Things" is interesting to me because there's a certain implication that we're actually talking to something that actuates or senses. Otherwise, we could go "A computer's a Thing, therefore we have the IoT already" - which we don't want to do because it's silly.

So what is does it mean to talk to a Thing? It means "unlock the door". It means "turn the light to 50% brightness". It means "start this motor". It means "the motion detector has sensed something".

These are all high level semantic concepts. Where do these fit? At the top of the stack, where HTML goes. Or to put it another way:

The Internet of Things is adding APIs to Things to control them semantically - using the standard Internet protocol stack.