Bluetooth's Journey Towards Internet of Things

Congratulations SIG on turning twenty. In current market scenario any technology sustaining for over two decades is a rare phenomenon. Bluetooth deserves a loud applause and attention too. This was possible through consistently sensing the market needs and catering to them, watching the competitors closely and evolving as a better choice and collaborating with partners at right time. Having visionary leaders and pioneers in technology on board is a great asset to SIG.

A decade ago when anybody asked what is Bluetooth and what it meant for, somebody would have answered - "Bluetooth is a peer-to-peer connectivity technology which enables wireless communication between two devices over unlicensed spectrum. You can get rid of a wire between your phone and headset or between your notebook and mouse, You can share files over the air". Just like any other short-range connectivity protocols, Bluetooth might have overlooked "Internet of Things" which was coined and conceived much before first Bluetooth specification was released. Probably thought "Internet is not my cup of tea". Kevin Ashton wouldn't have imagined that "Internet of Things" would become such a mammoth where in all the communication protocols would align themselves with or relate themselves to IoT. Long story short - Can any communication technology survive without claiming its role in IoT? "NO" might not be an exaggeration!

On successfully replacing the wire, Bluetooth started focusing on enhancing the transfer rates and evolved as the pioneer of "wireless file transfer", "wireless voice communication", "wireless music streaming", "wireless human interface". The supremacy was maintained till Wi-Fi alliance came up with Peer-2-Peer WiFi standards which enabled "wireless file transfer" with multi-fold faster transfer rate. To survive in the file transfer business, Bluetooth had to utilise 802.11 radio through alternate MAC/PHY feature.

Then connectivity technologies started expanding their scope into "Health & Fitness". Unlike conventional wireless communication, these domains need discrete communication with very small data. Radio can be put to sleep when there is no active transmission or reception. This vent a way to "low power" connectivity protocols. In early 2010 Bluetooth realised the need for discrete communication and advertising to "Offer Services" and "Seek Services". The result was Bluetooth Low Energy (BLE) and Generic Attribute Profile (GATT). Though Bluetooth came up with over twenty GATT profiles to aid coin cell powered health & fitness devices, it had to face tough competition from ANT+ and other proprietary solutions.

During similar time lines, IEEE 802.15.4 based connectivity protocols were leading "Home Automation", "Building Automation" and "Smart Energy" domains. Besides the MAC/PHY capabilities to aid many-2-many communication, a plethora of standards defining smart home  device capabilities, message semantics and inter device communication made them stand on the top in home automation. Topological limitations were not letting BLE to get its hands on home automation domain. Though CSR (now Samsung Electronics) came up with "Flooding" based solution, That was not an equally good parallel solution for well established "Mesh" based solutions such as ZigBee and Z-Wave. And 6LoWPAN was defined to enable IP communication over IEEE 802.15.4 powered devices.

Internet Protocol (IP) and Mesh were the essential requirements to enter into Internet of Things (IoT) space. SIG came up with Link layer topology, IP Support Profile to overcome topology limitations and to enable IP communication over Bluetooth link. Enhanced privacy and secured channel standards made Bluetooth more robust against eavesdropping and comply Federal Information Processing Standards (128 bit nonce for channel authentication). Data length extension increased the throughput up to 2.5x times.

Then Bluetooth was in a good shape to be called as potential candidate for home automation with many-2-many topology and enhanced privacy, security and throughput. However, the range was not sufficient to automate a building or a small industry. Compared to health & fitness use cases, home automation use cases need even better latency. For instance turning on a light with conventional switch is almost real time where as turning on light with wireless connectivity based switch is not yet there. In recent times many smart devices are being equipped with voice assistance. "Voice" is becoming the new form of human interface. Indoor positioning is adding value to home automation through identifying the device position, mapping the device to specific location, creating scenes based on user moments (with a wearable on).

In a nutshell - Internet Protocol Support, Mesh Topology, Enhanced Security, Long Range, High Throughput, indoor positioning and Profiles for IoT verticals are the potential differentiation factors in IoT connectivity. With latest 5.0 standard, Bluetooth stands tall as a IoT connectivity protocol.