The Internet of Things (IoT) is currently one of the fastest growing technology sectors. Various market analysts predict double digit growth for IoT-enabled devices. Bluetooth technology is set to play a significant part in that growth with its ability to easily connect “things” to host systems. IHS Technology predicts that the number of Bluetooth devices will rise from 2.4 billion in 2014 to 4.4 billion by 2019*. Already, Bluetooth technology is in a very good position for IoT applications. The introduction of Bluetooth 4.2 saw vital additions to the security features and the technological basis for a much higher data throughput – all without compromising energy efficiency.
By the end of 2016 or early 2017, the new Bluetooth standard version 5 is expected to be releases by Bluetooth SIG (Special Interest Group). The new release will feature two prominent improvements to enable Bluetooth to be used in even more IoT applications.
On the one hand, the realizable radio range of Bluetooth will be increased up to four times, compared to the current generation. This will be achieved by a more elaborate signal encoding. For Bluetooth Low Energy (BLE) Longrange, an unchanged 1 Megasamples/s modulation will be used, but unlike today, two or eight samples will be used for the arrangement of the individual bits (corresponding to 125 kbps / 500 kbps), so that FEC (Forward Error Correction) can be used. Especially in home automation deployments, where multiple walls can be between the communicating devices, or devices can be positioned far apart in the garden, the extended range will enable Bluetooth to be utilized a lot more in its new generation. Another interesting area of application will be smart cities, where high ranges restricted the use of Bluetooth communication until now.
The other vital improvement of Bluetooth version 5 aims at one of the core pain points for Bluetooth technology: increasing the data throughput. Bluetooth 5 defines, in addition to the standard modulation rate of 1 Mbps, another modulation rate of 2 Mbps, resulting in almost twice the maximum data throughput. Not only does this enable devices to transfer bigger data volumes in less time, power consumption is also decreased as a certain amount of data takes less time to be transferred, since power consumption in IoT devices comes mostly down to the time the transmission path is being used. 2 Mbps are mostly a theoretical value, though, with a protocol overhead of around 1.6 Mbps for data transfer in both directions to be expected in practice. Therefore, transmission of data in one direction, for example to a smartphone or tablet, will approximately happen at around 700-800 kbps.
Another vital feature of Bluetooth 5 are the so-called “Advertising Extensions” for Bluetooth advertising (permission based advertising), which allow for the continuation of an advertising outside of its regular channels. Applications such as beacons or the upcoming smart mesh are based on broadcast capabilities and can benefit from the increased data throughput, as more information can be transported with a higher broadcast capacity. In a broadcast application, there is no explicit connection between the participating devices. Broadcasted data can be received and read with any Bluetooth device within the range. Even though visible for anyone, that doesn’t mean the broadcasted data can be utilized by third parties, because it can be encrypted before broadcasting. Applications such as visitor counting, asset tracking, indoor navigation or smart lighting can be realized more easily and with a higher range of functions.
Overall, Bluetooth connections are getting faster as well as more reliable and resilient, making them more and more suitable for the demands on data traffic and security functions in IoT deployments.
In spite of all the changes introduced with Bluetooth 5, devices will still be downward compatible to Bluetooth 4.x devices. Nearly all relevant innovations in Bluetooth 5 are optional for implementation. When implementing Bluetooth 5, device A can have a different feature set than device B. From the outside, that may not be visible as both devices can be qualified for Bluetooth 5. With demands for ever higher data throughputs, though, it is to be expected that most devices will support the abovementioned Bluetooth 5 features.
Bluetooth 6 will further delve into this trend and will deliver new features especially for locating applications.
Telit is already working on a Bluetooth 5 compatible sensor-to-cloud solution. The recently launched Bluetooth Low Energy module “BlueMod+S42” is compliant with the requirements for a later Bluetooth 5 qualification and is primed for mesh applications.
