I’d like to announce that I have written a book proposing a
new architecture for the coming explosion of devices in the Internet of Things
(IoT). I hasten to add that I didn't set out to write a book – rather Intel
Corporation approached me on the basis of the blog posts below and asked me to
expand my thoughts into a more detailed treatment. You can click the link to learn
more about Rethinking the Internet of Things: A Scalable Approach to Connecting Everything.
I did not originally intend to develop a new architecture
for the IoT. Rather, I was thinking about the implications of control and
scheduling within machine social networks in the context of Metcalfe's Law. The
coming tsunami of machine-to-machine interconnections could yield tremendous
flows of information – and knowledge. The book builds on the principles outlined in the blog posts below, but it also expands on a number of new directions that I will touch on in later blog posts.
Once we free the machine social network of the drag of human
interaction, there is tremendous potential for creating autonomous communities
of machines that require only occasional interaction with or reporting to
humans. As the Internet of Things expands exponentially over the coming years,
it will be expected to connect to devices that are cheaper, dumber, and more
diverse. Traditional networking thinking will fail for multiple reasons.
Fundamentally, traditional IP-based peer-to-peer
relationships lock out much of the potential richness of the Internet of
Things. There will be vast streams of data flowing, many of which are unknown
or unplanned. Only a publish/subscribe architecture allows us to tap into this
knowledge by discovering interesting data flows and relationships. And only a
publish/subscribe network can scale to the tremendous size of the coming
Internet of Things. So appliances, sensors, and actuators must use
self-classified traffic schemes to allow for discovery and creation of
information “neighborhoods”.
Note that the data needs of the IoT are completely different
from the traditional global Internet. Most of the communications will be terse
machine-to-machine interchanges that are largely asymmetrical, with much more
data flowing in one direction (sensor to server, for example) than in the
other. And in most cases, losing an individual message to an intermittent or
noisy connection will be no big deal. Unlike the traditional Internet, which is
primarily human-oriented (and thus averse to data loss), much of the Internet
of Things traffic will be analyzed over time, not acted upon immediately. Most
of the end devices will be essentially autonomous, operating independently
whether anyone is “listening” or not.
Although IPv6 can potentially provide addresses for myriad
devices, the largest population of these appliances, sensors, and actuators
will lack the horsepower in terms of processors, memory, and bandwidth to run the bloated IP protocol stack. It simply does not make financial sense to
burden a simple sensor with all of the protocol overhead needed for
host-to-host communications.
Additionally, the conventional implementation of IP
protocols implies networking knowledge on the part of device manufacturers:
without centrally authorized MAC IDs and end-to-end management, IP falls flat.
Many of the hundreds of thousands of manufacturers of all sizes worldwide
building moisture sensors, streetlights, and toasters lack the technical
expertise to implement legacy network technology in traditional ways.
There is another subtle reason why a new architecture is
needed, and it relates to a favorite theme of mine: control loops. When there
are real-time sensing and response loops needed in the Internet of Things,
traditional network architectures with their round-trip control loops will be
problematic. Instead, a way would be needed to engender independent local
control loops managing the “business” of appliances, sensors, and actuators
while still permitting occasional “advise and consent” communications with
central servers.
The only systems on earth that have ever scaled to the size
and scope of the Internet of Things are natural systems: pollen distribution,
ant colonies, redwoods, and so on. From examining these natural systems, I
developed the concept of the three-tiered IoT architecture described in the book:
simple end devices, networking specialist propagator nodes, and
information-seeking integrator functions.
I hope that you’ll read my
explanation of why terse, self-classified messages, networking overhead
isolated to a specialized tier of devices, and publish/subscribe relationships are the only way to fully distill the power of the coming Internet of Things.
And I hope especially for your feedback, pro and con.
