New Tech Europe | Jan 2017 | Digital Edition

IoT Special Edition

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

Figure 1: The Thread protocol block diagram (Courtesy of the Thread Group)

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,

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

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