Martin Woolley tells Martin Cooper how, after 20 years of huge growth, Bluetooth continues to develop at a huge pace and how it can support far more than just wireless headphones.

‘So, I’m Developer Relations Manager, EMEA for the Bluetooth Special Interest Group (SIG),’ says Martin Woolley. ‘I write and create learning resources for developers so they can get hands on and develop things, speak at lots of technical conferences and provide technical support. It’s no small undertaking, as Bluetooth is on pretty much everything you can imagine.’

Adding details, he tells ITNOW that, in 2000, around 800,000 Bluetooth-enabled devices were shipped. Today, 10 million such devices are sent towards customers and consumers - each day. This means, in its 20 years of ratified existence, billions of devices capable of wire-free, interoperable communications have shipped.

Viking kinds and standards

As a technology, Bluetooth’s seeds were sown by Ericsson in Sweden, during the late 1980s. Back then it was conceived as a short distance radio link designed to end the need for headphone wires.

Doubtlessly a firm favourite for the geeky pub quiz comperes, Bluetooth takes its name from Herald Bluetooth, a 10th century king who was remembered for uniting a nation of tribes into one kingdom. For extra points, it’s worth remembering this all happened in 1997 and was intended to convey the idea that Bluetooth was a way of uniting vying communication protocols.

The Bluetooth SIG is a standards organisation. It doesn’t make or produce software. Rather, it collects and defines the specifications that describe and define how Bluetooth works. It also evolves and grows these specifications.

‘The standards are defined in meticulous detail, covering everything from how radio waves should carry information right up to how a specific product should behave and its capabilities. And there are several different flavours of Bluetooth, but we’ll come on to that later,’ Woolley states.

The SIG, like Bluetooth, has been around for 20 years. It is a membership organisation and has around 35,000 members - these are the companies who use the technology in their products and want to be involved in Bluetooth’s constant evolution. ‘The IPR is owned jointly by all our members. It’s quite an unusual licencing arrangement. This is shared ownership. We are the hub,’ he says.

Three flavours of blue

Back in 1998, when the SIG was established, Bluetooth 1.0 was just one standard. Today, Bluetooth is really a catch-all name for three different technologies. First is Bluetooth BR / EDR or basic rate/enhanced data rate.

This is the original type of Bluetooth - the familiar cable replacement technology. It’s very good at handling a steady stream of data. This is why it is still so strong in the audio market. It’s also a one-to-one model where two devices communicate in isolation. 

The next significant form of technology is Bluetooth Low Energy (Bluetooth LE). As its name suggests, Bluetooth LE consumes much less power than BR/EDR, while maintaining a similar level of connectivity. Bluetooth LE is supported natively by all of today’s major mobile and PC operating systems.

‘Bluetooth LE was designed to carry smaller amounts of data,’ Woolley says. ‘The sorts of data that sensors might transmit. You’ll find lots of Bluetooth LE devices running on tiny coin-sized batteries, which last for years. I’ve got some devices that don’t have batteries... The power requirement is so low they’ll operate with small solar panels. And they don’t even need direct sunlight. They’ll work off ambient light inside a building.’

Bluetooth LE’s importance shouldn’t be underestimated. It is one of the key building blocks that enable the internet of things to move from just an idea to become a revolutionary force. Many IoT devices have sensors, data reporting mechanisms or communicate with other machines. And it’s here - at the edge of a network - where Bluetooth LE comes into its own.

‘It comes down to this,’ says Woolley. ‘What does “smart” actually mean? Is it a marketing term that we slap in front of everything? The word “smart” is on trend at the moment. But, put your critical thinking hat on and think about what it really means.’

And to Woolley, it comes down to this: smartness, intelligence, or awareness all relate to the availability of data. ‘You need data, for many perspectives, to describe the state of the building, the environment or the system. And you need that data collected over time. So, sensors are critical to the acquisition of that data. With that data you can derive intelligence and start making predictions. These ideas are central to the idea of smartness.’

Making the world smarter

The challenge is that, in complex places like buildings and even cities, many of these sensors are going to be installed in inconvenient places. They might be under the ground or embedded in walls. They might even be in environments hostile to people. So, powering these devices is a real challenge - you can’t use a technology that needs battery changes, for example. ‘You’ve got to have something that’s absolutely the most efficient,’ explains Woolley.

Beyond frugality, there is another difference between BR/EDR and Bluetooth LE. While both can work as cable replacement technologies, Bluetooth LE can also broadcast data - it has a one-to-many capability. This means that one device can broadcast some information, and any others that are within range can receive and process the data. ‘It’s a very scalable technology,’ Woolley says. ‘There are no limits to how many devices can receive the information.’

This one-to-many capability gave rise to Bluetooth beacons. ‘A beacon is an application of Bluetooth LE,’ Woolley explains. ‘Apple’s iBeacon popularised the technology. The device broadcasts a message that contains an identifier which is associated with a thing or a place.

A smartphone could take that unique ID inside a broadcast, look it up in databases and go: “Aha! I’m next to the Mona Lisa!” or “I’m in the Kingston upon Thames branch of John Lewis in the sports department”. So, it’s about mapping. This is an immense area of growth for Bluetooth. We’re expecting there to be 550 million beacons shipping in 2021 - specifically in that one year. That’s one of Bluetooth LE’s big success stories.’

Location, location, location

Don’t think that Bluetooth beacons are a thing of the future though. ‘They’re already making indoor environments easier to navigate,’ Woolley says. ‘I saw something in Milton Keynes. Beacons were deployed across a big shopping centre specifically to provide assistance with visual impairment. The system gave guidance about where people were in terms of locations and also what was on offer in the shops they were near, using audio announcements.’

There’s also work happening in Europe around standards for Bluetooth LE to be used in ticketing and in transportation. Instead of using NFC like the Oyster Card, a Bluetooth LE system would allow people to pay for train and bus tickets by simply walking into a specific area. Your smartphone will have a conversation with the ticket seller and you’re on your way. There’s no need to make a physical gesture like with an NFC device. ‘Just step into the train station or stand on the bus. And that’s very real.’ Woolley explains.

The newest Bluetooth technology is Mesh. It provides developers and engineers with the ability to make networks that might contain tens of thousands of devices. It can be thought of as a many-to-many mode of communication. This means that any device in the mesh network can talk to any other device and vice versa. At its heart it uses Bluetooth LE as its radio technology and was, initially, conceived as a system designed to run smart buildings.

Smart building controls and data

In a true smart building, many elements in the services we use - bulbs, switches, air conditioning systems, electric blinds and all the rest - can all be members or nodes in a Bluetooth Mesh network. This means they can all be controlled and monitored wirelessly. Mesh also allows sensors to be included in a grid of devices so data can be gathered and building automation, driven by sensor data, can be implemented.

The ultimate aim, in many ways, is to ensure that the building is running at its optimum and using only the minimum amount of power to keep costs low while at the same time providing an excellent environment for building users.

‘One of the key characteristics of a mesh network is that signals aren’t constrained by radio range. I could send a message from one light switch to a group of lights that are perhaps on the top floor. The lights can be way out of radio range, but that’s okay. The message from my switch will hop across the network through a process called relaying.’

It’s possible to do 127 hops across the network and it happens very quickly. ‘Messages travel across the network, in a multi-hop scenario, at the speed of sound. But with 127 hops possible and each one being, potentially, hundreds of meters, you can envelope a whole building, or even a whole neighbourhood very quickly.’ 

‘Bluetooth Mesh is going to be dominant in smart buildings,’ Woolley says. ‘I’m confident of that.’