Lighting Systems Get an IoT Facelift With Bluetooth Mesh

Wireless lighting systems are not only more flexible than wired systems; they also form a backbone for transmitting different sensor data, device status information, and commands. 

Recently, Universal Douglas Lighting Americas, a leading manufacturer of lighting equipment, partnered with u-blox, a global provider of positioning and wireless communication technologies, to develop a Bluetooth mesh-based platform for building automation applications, including smart lighting, access control, and energy management.

 

Block diagram of the NINA-B40 underpinning the mesh platform. Image used courtesy of u-blox

 

The new mesh platform will be designed around the u-blox NINA-B406 Bluetooth low-energy module. Other lighting equipment and wireless chip providers, like Hytronik and Nordic Semiconductor, are similarly collaborating on Bluetooth mesh sensors.

Bluetooth mesh, introduced in 2017, seems to attract a lot of attention in different building automation applications, especially in lighting systems. Below, we’ll take a closer look at why Bluetooth mesh is gaining traction in these applications and what advantages this protocol has to offer.

 

Adding Mesh Capability to Bluetooth 

While IoT wireless connectivity solutions, such as Zigbee, have been designed to support mesh networking capability from the ground up, the mesh feature was added to Bluetooth only a few years ago in 2017. This belated addition stems from the fact that Bluetooth was originally designed as a cable replacement for short-range communications such as the RS-232 protocol.

The mesh-capable version of Bluetooth is referred to as Bluetooth mesh to distinguish it from non-mesh versions of Bluetooth. 

 

A brief history of Bluetooth's evolution. Image courtesy of J. Yin et al.

 

Mesh networking can extend the coverage range of the network beyond that of a single radio and enhance the system reliability. With the mesh feature included, Bluetooth is now able to compete with other mesh-capable protocols such as Zigbee and Thread. Is one of these protocols superior among all mesh-capable connectivity solutions? 

 

Unparalleled Ubiquity

One advantage of Bluetooth mesh is that Bluetooth is far more ubiquitous than other protocols. While only about 300 million Zigbee nodes are currently deployed worldwide, four billion Bluetooth devices ship every year.

The Bluetooth mesh protocol stack uses BLE (Bluetooth low energy) for radio communications. To support Bluetooth mesh, most laptops, smartphones, and tablets have built-in BLE chips and require only a software update. Because of this unmatched adoption rate, it's possible that Bluetooth mesh may take over a significant portion of its competitors’ market in the years to come. 

 

Designed With an Eye on Lighting Systems

Bluetooth mesh is more than just a wireless connectivity solution. In fact, Bluetooth mesh might be considered a full-stack solution that supports application-specific features in addition to the required radio communication protocol. 

 

Bluetooth mesh can bring more functionality to lighting systems. Image courtesy of Nordic Semiconductor

 

One of the important application areas supported by Bluetooth mesh is the lighting industry. Bluetooth mesh has lighting models that support sophisticated, modern lighting systems. Models are software modules that implement behaviors of a mesh application. Lighting models of Bluetooth mesh control different characteristics of a lighting product, such as on/off, level, color, temperature, lightness, lightness range, hue, saturation, chromaticity coordinates, and more.

 

The Possibilities of Bluetooth Mesh Lighting

Smart lighting systems may one day exist everywhere from factories to airports to shopping malls. This is possible because of the widespread adoption of BLE-supporting smartphones as well as the fact that Bluetooth mesh supports beacons. This beaconing capability can enable multi-purpose IoT networks—that is, a lighting system that also performs indoor positioning in a shopping mall.

Supporting beacons, Bluetooth mesh may be especially useful in automation-heavy environments. Image courtesy of Bluetooth SIG

 

With this Bluetooth mesh, future wireless lighting systems may one day be the mainstream platform for measuring and transporting sensor data in commercial environments. 

 

The Drawback of Bluetooth Mesh: Latency

While Bluetooth has the advantage of widespread support, developers should also consider a number of other influencing factors, including network latency, scalability, and throughput.

Different research groups and chip manufacturers have conducted experiments to compare the performance of Bluetooth mesh with other mesh-capable protocols such as Zigbee and Thread. According to experiments conducted by Silicon Labs, as the payload and the scale of the network grow, Zigbee outperforms Bluetooth mesh in terms of latency. 

 

Comparison of the latency of protocols over four hops. Image courtesy of Silicon Labs

 

The design of Bluetooth mesh networks might also be more intricate. In order to realize the full performance potential of a Bluetooth mesh network, engineers need to carefully adjust different parameters of the network. For example, employing an unnecessarily large number of relay nodes in a Bluetooth mesh network can increase the packet collision rate, delay, and energy consumption of the network.

Even so, Bluetooth mesh looks equipped to compete with other mesh-capable protocols. 

 

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