Turning the Industrial IoT toolbox Blue(tooth)
Interview with Mats Andersson, Senior Director Technology, Short Range Radio Product Center, u-blox
ANDERSSON: Bluetooth 5 introduces several enhancements on top of those enabled by Bluetooth low energy (BLE) technology that further allow Bluetooth to move from a cable replacement technology to a network-oriented technology, and thus better able to support IoT applications in all vertical segments.
This evolution began with the Bluetooth Special Interest Group (SIG) adopting BLE technology (previously known as Bluetooth Smart) into the mainline of the Bluetooth Core Specification in 2010, which was then dubbed Bluetooth 4.0. Although this initially lowered the maximum theoretical bandwidth of the technology from the low megabyte range to the hundreds of kilobytes, BLE also reduced power consumption by orders of magnitude (from approximately 1 W transmission power into the milliwatt range) and minimized latencies into the low milliseconds while retaining similar range to its predecessors. Furthermore, Bluetooth 4.0 added support for the IPv6 protocol developed to provide enough address space for all the “things” connecting to the Internet.
All of this had two effects on Bluetooth’s addressable market. First, it opened up a range of new applications for Bluetooth beyond the traditional consumer space, some of which included commercial and IIoT applications governed by latency and power consumption more so than sheer throughput. Second, it provided an upgrade path for legacy Bluetooth devices, which helped bring consumer economies of scale into these emerging markets; billions of Bluetooth devices are shipped year over year, making the technology extremely cost competitive regardless of application.
Bluetooth 5 essentially brings more tools to the toolbox for designers of all kinds of connected applications, including increased range (up to 4x) and throughput (2 Mbps link performance compared to 1 Mbps today) that can be tuned on a sliding scale with power consumption based on specific system requirements. Perhaps more important, though, is mesh networking capability. Bluetooth Mesh can be considered a true mesh network in that the specification will not require a network hub or gateway, which both reduces single points of failure to improve network reliability and enables the capacity to support tens of thousands of nodes that can almost limitlessly extend the range of a Bluetooth signal.
Moving forward, even more support can be added with IPv6 over Mesh, all while maintaining compatibility with the installed base of Bluetooth devices. Considering the range, throughput, power consumption, mesh networking, compatibility, and cost advantages of the Bluetooth specification today, many industrial and building automation applications stand to benefit.
With the potential benefits of consumer wireless standards for the IIoT space, are long-lived 802.15.4-based technologies set to be replaced?
ANDERSSON: The benefits of Bluetooth mentioned previously that extend the technology’s utility as a networking toolbox can, in a number of applications and vertical markets, replace incumbent 802.15.4 devices and protocols, be they standards-based or proprietary. As IoT systems and architectures in general move increasingly towards IP-based backbones in not only the data center and gateway but also at the edge, Bluetooth will continue to advance the proliferation of TCP/IP through IPv6-based networks. As a happy byproduct, this will also solve many of the network interoperability issues that occur at the intersection of operational technology (OT) and information technology (IT) networks.
Of course, there is no one-size-fits-all networking technology when it comes to the IoT, and niche application areas will remain that require extremes in terms of wireless latencies. Here, Bluetooth may not be a fit, but 802.15.4-based solutions may not either, for that matter.
However, where it can be used, it’s better to do so than go against the grain. Doing so can hurt device manufacturers in terms of time to market as well as reliability, particularly when using proprietary technology. A good example of this is security. Recently, British and Belgian security researchers found vulnerabilities in the communications protocols of no less than 10 implantable cardiac defibrillators (ICDs). Conversely, Bluetooth has featured “Secure Connections” since version 4.2, when Federal Information Processing Standard-compliant (FIPS-compliant) levels of link layer security were added. The move towards IPv6 technology also enables tested and trusted end-to-end security protocols like TLS/DTLS to be leveraged in Bluetooth-based applications, and Bluetooth 5 will continue this tradition in upcoming releases to meet stringent government-class security requirements. The soon-to-be-released Bluetooth Mesh specification also has a large emphasis on security.
Given time, the choice of Bluetooth technology in most IoT and IIoT edge networking applications will be a simple one.