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Figure 1: The Thread protocol block diagram (Courtesy of the
Thread Group)
and chief Internet evangelist, Google,
and advisor to the Thread Group, so
the Thread protocol takes existing
technologies and combines the best
parts of each to provide a better way to
connect products in the home.
Unlike many existing technologies
or IoT approaches, Thread is not an
application protocol or a connectivity
platform for many types of disparate
networks. This is an IPv6 networking
protocol built on open standards and
specifically optimized for low-power
802.15.4 mesh networks. As a result,
existing popular application protocols
and IoT platforms can run over Thread
networks. This provides a significant
advantage for the consortia members
looking for Thread to be adopted by
equipment makers. Millions of existing
802.15.4 wireless devices already on
the market – mostly running ZigBee
- can run Thread with just a software
enhancement with no new hardware
required. This will be a potential
benefit to chip makers such as Atmel,
Silicon Labs and Texas Instruments
who already supply devices using the
ZigBee protocol and have extensive
experience with mesh network
application software.
However, there are several other
technologies looking to be the platform
for IoT applications.
ZigBee sees itself as a key IoT
technology, with the mesh network that
uses the same 2.4GHz radio front end.
Unlike 6LoWPAN, ZigBee uses a hub to
connect up the IoT sensors, although
the latest version supports IPv6 and
more direct connections as well as low
power modes with higher data rates.
Thread will also be competing with
other low power technologies that are
emerging for the Internet of Things.
The Bluetooth Special Interest Group
(SIG) has approved two new low power
versions of the point to point protocol,
for Bluetooth Low Energy (now called
Bluetooth Smart). BT Smart 4.0 and
4.1 add new low power modes to cut
the power in connecting devices – 4.0
for personal devices such as fitness
monitors and 4.1 for longer range IoT
devices. Cambridge Silicon Radio also
has a technology called CSRmesh that
uses BT4.0 to provide a low power
mesh network for IoT applications
similar to ZigBee but without the hub.
It is making this an open protocol and
the Bluetooth SIG is working on a mesh
version to standardize.
At the same time there is also a proposal
from 6LoWPAN to include elements of
this technology in Bluetooth Smart.
WiFi also has not stood still in looking
at low power. The latest version of the
802.11 standard that is used to power
wireless networks around the world
moves to the sub Ghz band to save
power and provide longer range, and
many of the WiFi silicon suppliers are
positioning for this new technology
called 802.11ah. This is currently
undergoing voting by the IEEE, also
removes the need for regular polling
that made WiFi a relatively power
hungry technology. The combination
of low power modes, much longer
sleep modes and operation at around
900MHz will make WiFi a significant
contender for low power IoT networks
as nodes will be able to automatically
join existing wireless networks.
Imagination
Technologies
has
developed a configurable radio
processing unit (RPU) that can
handle all the WiFi protocols including
802.11ah as well as Bluetooth 4.0
and 4.1 and, if necessary, ZigBee,
with low power in mind. The Whisper
architecture combines a configurable
modem block with much of the MAC
functions handled in a Warrior class
MIPS processor. The RPU design will be
available for licensing to chip makers
towards the end of 2014 and allows
the device makers to have a single
underlying architecture and configure
IoT
Special Edition
New-Tech Magazine Europe l 41