Bluetooth 5.1: What the Latest in Generation 5 Has to Offer

one month ago by Sam Holland

‘Bluetooth’ is named after the English translation of 'Blåtand': the surname of King Harald Blåtand, who unified Denmark—so in his memory, it’s no surprise that the wireless standard has remained an important part of the connected world since the late 90s. Now, it’s more communicative, efficient and scalable than ever: here’s a look at what’s putting the ‘.1’ in ‘Bluetooth 5.1’.

Following Bluetooth Special Interest Group’s (SIG) market introduction of Bluetooth 5 on the 16th of June, 2016, Bluetooth Core Specification v5.1 (shortened here to 5.1) was introduced on the 21st of January this year. Focusing on both the former and the latter, let’s start by considering respectively what has brought Bluetooth its fifth generation title, and of course where the latest update comes in.

Bluetooth Low Energy (iPhone devtool version). Image courtesy of iTunes.

BLE: Bluetooth’s 5th-Generation Turning Point

This decade has seen a milestone in both Bluetooth connectivity and power efficiency, thanks largely to Bluetooth Low Energy (BLE), originally called Bluetooth Smart, which was first introduced in the 2011 release of 4.0.

BLE’s introduction was crucial, as the tech continues to ensure the best of both worlds: it transmits an always-on signal, but can remain in its sleep mode to avoid the device battery drainage (an infamous issue in pre-2011 Bluetooth) that would otherwise come from having a permanently-transmitted frequency (at around 2.45 GHz).

Naturally, from its lower energy consumption has come higher efficiency; to break down the 3 core improvements that generation 5 has over its immediate predecessor, 4.2:

a) Twice the speed;

b) 4 times the range;

c) And 8 times the data transmission potential.

Consumer-wise, such enhancements in efficiency have even led to dual headphone connectivity; but more importantly, the above breakthroughs have also accommodated broader benefits, including the following: position tracking and IoT functions.

Position Tracking

Bluetooth 5, particularly given its said BLE functionality, has already proved its worth in position tracking (PT) and wayfinding; this is through its facilitation of BLE beacons, whose above-mentioned power efficiencies allow them to be always-on, providing location services (plus Bluetooth proximity marketing) to the smartphones and watches of passersby.

Various points of interest that may be brought to the attention of a Bluetooth marketing recipient. Image courtesy of Dribble.

But while this mainstay of Generation 5 has indeed introduced BLE-based location services (another popular example being airport wayfinding) such PT technology is accurate to the metre at best. Now, 5.1 has come with centimetre-level accuracy, thanks to the introduction of its ‘angle of arrival’ (AoA) and ‘angle of departure’ (AoD) PT techniques.

About AoA and AoD

Put simply, AoA is when the antenna array (internal or otherwise) of a Bluetooth receiving device calculates the angle of an incoming RF signal, relative to the transmitting device that sent it; whereas AoD is essentially the other side of the same coin: the Bluetooth transmitting device calculates the angle of its outgoing RF signal, relative to the receiving device.

Diagram that shows ‘angle of arrival’ and ‘angle of departure’ position tracking techniques in action. Image courtesy of Bluetooth Special Interest Group.

Regardless of the method used, it is 5.1’s BLE controller that then calculates the position of the device of interest—let’s use a Bluetooth beacon as an example here—with up to 3 times the accuracy of 5.1’s immediate predecessor. And the controller does not just figure out the beacon’s position in 2D, but in 3D space as well, as demonstrated in this video by Silicon Labs.

The Bluetooth SIG achieved such a feat in light of the growing location services market, and it’s easy to see why such a field has taken off. After all, aside from the said wayfinding applications, consider the industrial potential alone: for instance, the future of inventory management has become all the brighter, thanks to 5.1's AoA and AoD granting warehouse operatives the potential to accurately track their target product's BLE beacon more than ever before—whether it's on the lowest or the highest depot shelf, or anywhere in-between.

Of course, stock control is still just the beginning for 5.1’s position tracking potential: the SIG say their technology has further enabled other developers to enhance existing PT technology all the more: “Once the associated profiles have been released”, their 5.1 specification explains, look forward to further developments in “high-accuracy, interoperable systems, such as real-time locating systems”.

Bluetooth in the IoT: What 5.1 Means for Consumers and Industry

Ultimately, 5.1’s principle improvement is in its said position tracking feature, as it offers the ability to pinpoint people and objects’ location through an energy-efficient and consumer-friendly standard.

For the average consumer, such an accurate level of position tracking could soon add peace of mind to anyone who loses their keys or phone; or on a more serious note, someone whose child runs too far ahead in a shopping centre—in fact, the technology could even one day apply to search-and-rescue, for as long as developers, amateurs and blue-chips alike will continue to enhance 5.1 further still.

And as for the engineering sector, 5.1 has the potential to facilitate worldwide improvements in manufacturing and distribution efficiency: manufacturing due to how easily engineers and robots alike will now be able to better pinpoint the required components; and distribution, given the speed at which stock controllers will now be able to manage warehouse operations.

All in all, the latest version of Bluetooth’s 5th generation shows great promise for both industry and consumers.