Learn from our experiences about Bluetooth mesh networking, how and where to use it. We’ll tell you about the design and operation principles of this protocol and compare it with similar technologies, such as Zigbee and Thread. In our Bluetooth mesh guide, you’ll learn about the advantages of this networking standard and the challenges our team has met working on BLE mesh projects.

If you’re choosing an out-of-the-box and easy-to-implement solution to build decentralized wireless networks, Bluetooth mesh may be an option.

This protocol can provide secure and reliable communication between multiple devices on a large-scale network. BLE mesh can compete with Wi-Fi, Z-wave, Zigbee, Thread, and other technologies in the context of the Internet of Things and smart connectivity.

However, this is not a one-size-fits-all solution, and like any other technology, it has both strong and weak points. Using our personal experience with Bluetooth mesh network , we’ll shed some light on this standard to help you understand whether it works for you.

What Is A Bluetooth Mesh Network?

What is a mesh network, broadly speaking? A mesh network is a network of devices, or nodes, connected directly, dynamically, and non-hierarchically to as many other nodes as possible. The nodes cooperate with each other by exchanging data.

A Bluetooth low energy mesh network is a meshnet based on BLE technology.

The Bluetooth Special Interest Group (Bluetooth SIG) first introduced Bluetooth Low Energy or BLE in 2009. In early 2010, it was completely integrated into Bluetooth 4.0. The new technology was designed for smart connectivity systems with low power requirements.

However, the abilities of BLE networks were quite limited. Bluetooth Low Energy allowed for one-to-one communication, and simple devices (like beacons) within a network could communicate only via the central hub.

The release of the Bluetooth mesh networking standard became a game-changer in 2017. The Mesh Profile specification, added to Bluetooth 5, provides the possibility for many-to-many communication.

Bluetooth mesh is intended for networks with a large number of nodes – mesh devices that broadcast messages. It targets the growing IoT market which continuously demands:

• more energy-efficient solutions;
• more security;
• more communicating devices;
• more flexible technologies.

As part of our IoT solution development services, we can build a BLE mesh network of diverse complexity for your project.

How BLE Mesh Network Works

What differentiates the Bluetooth LE mesh network from Zigbee/other forms of technology, in the first place, is broadcasting messages. Unlike the other wireless networks based on routing, the BLE mesh protocol applies the managed flood principle.

This approach offers a peer-to-peer communication model in which all nodes, or devices, communicate directly with each other. Managed flooding makes messaging efficient without complex routing algorithms. You don’t need to use the central hub but you can relay messages straight to the right nodes without any interruptions.

The self-sufficiency of the nodes, coupled with multipath messaging, facilitates the scalability of BLE mesh networking. It can help you create countless networks with innumerable nodes.

In a BLE mesh network, nodes use the publish/subscribe model for communication. Publishers send messages to multiple devices. To receive particular messages, a device must subscribe to various addresses (or a set of addresses).

BLE mesh network works:

Example of a BLE mesh network. The message is transmitted from Publisher to Subscribers 1 and 2.

This type of messaging gives you an opportunity to configure BLE mesh devices to form network segments of different scale and purpose. As a consequence of this configuring, technology becomes even more flexible and manageable.

BLE mesh architecture has a multi-layer structure typical of any communication network:

• The upper layers take responsibility for the contents of messages.
• The middle layers are responsible for the logic and behavior of the network.
• The lower layers define message transmission.

Bluetooth mesh networking places a strong focus on security. There are encryption and authentication systems for all messages based on the AES-CMAC and AES-CCM algorithms. The security keys protect the contents of messages and ensure sensitive communication between the nodes.

The use of security credentials protects the BLE mesh network from unauthorized access. Provisioning, or adding a device to the meshnet, is also secure. A new node provisioned on the network gets a unique ID and access to the security keys.

You can create a mesh network using literally any low energy Bluetooth chip or microcontroller that supports the technology. The popular manufacturers, such as Nordic Semiconductors, Texas Instruments, STMicroelectronics, Silicon Labs, Qualcomm, and others, produce the hardware and provide SDK to build custom BLE mesh networks.

The main challenge is not just choosing hardware, but creating a viable meshnet. Within our electronic design and firmware development services, our engineers will select the right chip and build a mesh architecture according to your project requirements.

Why Use A Mesh Network?

Just like other Bluetooth LE networks, BLE mesh features low power consumption. Therefore, this technology works well when one needs to cover a large area and save energy at the same time.

The connection-based Bluetooth network requires a connection between two devices or a stable configured route so that a message could travel through several nodes until it reaches the addressee. But in a BLE mesh network, nodes can be disconnected without serious consequences. If one of the devices disappears, the initial node will continue broadcasting the data. The addressee will receive the packet with just a few seconds’ delay.

Most of the standard implementations provide no guarantee of this. However, the mesh network is different. It reconfigures itself. It is flexible, which is sometimes more important than a guaranteed speed and shorter delays.

Nodes in a Bluetooth mesh network may change their position without breaking the whole network structure and without losing transferred data. Data loss is possible only if the nodes leave the coverage area of the receiver.

BLE mesh nodes can communicate with Bluetooth 4.x and 5.x devices. A Bluetooth 4.x compatible device will be able to receive messages. But it will not become a fully-fledged node of the network as it can communicate only with the paired device.

Now, there are a growing number of devices that support BLE mesh. One of the most promising areas for Bluetooth mesh networking is mobile communication because smartphones are compatible with Bluetooth 4.0 and BLE.

BLE mesh technology is closely connected with beacons. BLE beacons are broadly used in sensor networks, indoor and outdoor positioning, and other low-power connected systems.

As a highly flexible, energy-efficient, and secure solution, BLE mesh can find use in traditional networking applications, such as:

• Home automation
• Industrial automation
• Smart lighting
• Asset tracking
• Proximity detection

Our development experience proves that you can use this technology as a nonstandard solution for your project. Further in our guide, we’ll give an example of a BLE mesh network used for an unconventional application.

BLE 5.x Mesh Compared to Similar Technologies

Apart from BLE mesh, there are other similar mesh networking technologies.