Bluetooth mesh what it is, how it works and what it is for. New scenarios for the Internet of Things
Bluetooth mesh what it is, how it works and what it is for. New scenarios for the Internet of Things
We have been talking about WiFi mesh for years and how these systems help to extend the coverage range of the wireless network, improve the availability and reliability of the connection, avoid sudden disconnections, and use the same SSID, i.e. the identifier or WiFi network name, anywhere.
There has been less discussion, however, of Bluetooth mesh, a wireless communication technology that allows devices to communicate with each other in a flexible and dynamic way, forming a network of interconnected nodes.
We have seen what it is and how to activate Bluetooth on your devices as well as the differences between classic Bluetooth and Bluetooth Low Energy (BLE).
Traditional Bluetooth is not compatible with Bluetooth LE and vice versa but there are many devices that support both within the same product.
Devices such as smartwatches, smart fitness bands ( fitness trackers ), and other wearable products typically use BLE to maximize battery life and therefore range while still being able to communicate with your smartphone and other devices.
Most of us have heard of point-to-point communications in the case of both classic Bluetooth and BLE: the devices talk to each other using a two-way channel which is still “one-to-one”.
In a mesh system, however, communications are by definition many-to-many. The Bluetooth mesh scheme is no exception, which allows the exchange of data between nodes located in multiple physical locations using only the BLE specifications. There are also more routes or more “roads” to reach another node connected to the mesh network. This feature is particularly useful for guaranteeing the reliability of the Bluetooth mesh network and ensuring a certain resilience, for example in the event of a problem affecting a single node.
The benefits of a Bluetooth mesh network
In a Bluetooth mesh network, each device can act as a repeater and route messages across the network to reach devices that would otherwise be out of range. Mesh technology is therefore very useful for extending coverage and communicating with devices that otherwise would not be reachable from a single Bluetooth device.
It is also possible to manage a large number of devices with minimal resource and energy consumption. Additionally, the Bluetooth mesh approach ensures maximum compatibility with existing devices, including notebooks, Android and iOS smartphones, tablets, 2-in-1 systems, and so on.
Devices can also be easily added or removed from the Bluetooth mesh network without having to change the configuration of each one.
Lo schema Publish-Subscribe
With Bluetooth mesh technology, the publish-subscribe scheme is used to allow devices to send and receive messages within the network.
What is this particular pattern all about? Bluetooth devices can send messages to certain addresses ( publishing ).
At the same time, devices can “subscribe” to Bluetooth communications of interest to receive relevant messages ( subscribing ).
Bluetooth devices can thus communicate with each other without the need to establish a direct connection.
What is relaying in Bluetooth mesh networks
We have said that a Bluetooth mesh network allows you to cover even large areas. When there are walls or other architectural elements that do not allow a Bluetooth device to reach the others directly, the mechanism called relaying is used.
That is, it is possible to set up the devices as relays, intermediate nodes that take care of routing the message until it reaches the destination.
In addition to extending the coverage range, relaying also increases the robustness of the network as it allows you to create alternative communication paths that can be exploited in the event of problems on individual Bluetooth devices.
Devices can be configured as permanent or temporary relays as needed. They can also be set to only route messages of a certain type or to only route messages to certain devices.
Managed flooding: what is its use
Thanks to managed flooding, a device connected to the Bluetooth mesh network can send the message to all the nodes present without the need to know the identity or exact location of the recipients.
Devices receiving the message check the recipient address within the packet and if they are not the actual recipient they forward it until it reaches the correct recipient or is deleted. No node has to assume the responsibility of acting as a specialized router (think for example of the role typically played by a WiFi router, an access point, or an Ethernet switch ).
This method of communication guarantees the delivery of the message even in the event that problems occur on the intermediate devices. A number of routing algorithms determine the best path to route messages through the network.
It is possible to apply filters to limit the propagation of messages based on certain characteristics (for example based on the sender or the recipient) and automatically avoid congestion phenomena.
What is Thingy:53 and how to implement Bluetooth mesh
Nordic Semiconductor’s Thingy:53 platform is a development solution that integrates a broad range of sensors and wireless capabilities into a single compact device.
Thingy:53 uses a BLE module, supports the Matter specification that will be increasingly essential for smart home devices, NFC , is open to machine learning, and has things like an accelerometer, gyroscope, magnetometer, temperature sensor, humidity sensor, pressure sensor, and ambient light sensor.
The device is also equipped with a microphone, speaker, and a programmable button; it can be powered by either an internal battery or an external power source.
It also uses an ARM Cortex-M33-based SoC capable of handling a high computational load without negatively impacting the wireless connection.
A device like Thingy:53, which costs around 50-60 euros, can be easily integrated into different applications for the Internet of Things: home automation, environmental monitoring, industrial automation, health monitoring, and much more.
Supplied with a dedicated mobile app, compatible with Android and iOS devices, Thingy:53 is easily configurable to create a Bluetooth mesh network and is thus adaptable to any project you may have in mind.
Nordic Semiconductor also provides a wealth of code examples and technical documentation to assist in the development of custom applications based on Thingy:53.
Bluetooth mesh: what it is, how it works, and what it is for. New scenarios for the Internet of Things
Ultimately, Bluetooth mesh and a product like Thingy:53 are particularly useful for applications where it is necessary to communicate with a large number of devices, such as in automation, smart lighting, and industrial control systems.
With the ability to build robust and scalable networks, Bluetooth mesh and Thingy:53 allow you to develop advanced and complex IoT solutions.
