We describe what Bluetooth mesh networks are and how they work. Because they are useful in the industrial sector but also for the smart home.
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 mesha 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 and Bluetooth 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 smart watches, smart fitness bands (fitness tracker) 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 both in the case of classic Bluetooth and BLE: the devices communicate with each other using a bidirectional channel which is in any case “one-to-one”.
In a the mesh systemhowever, communications are by definition many-to-many. The pattern is no exception mesh Bluetooth 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 function as a repeater and route messages across the network to reach devices that would otherwise be out of reach. The mesh technology proves to be very useful, therefore, to extend the coverage and communicate with devices that otherwise would not be reachable from the single Bluetooth device.
You can also manage a large number of devices with a minimum consumption of resources and energy. 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 of them.
Lo schema Publish-Subscribe
With Bluetooth mesh technology, the scheme publish-subscribe it 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 them 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.
That is, you can set the devices as relayintermediate nodes dealing with route the message until you reach your destination.
In addition to extending the range of coverage, the relaying also increases the network robustness since it allows you to create alternative communication paths that can be used in the event of problems on individual Bluetooth devices.
Devices can be configured as permanent or temporary relays according to the requirements. 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 therecipient address inside 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 take responsibility for acting as router specialized (think for example of the role typically covered by a WiFi router, an access point or an Ethernet switch).
This method of communication guarantees the message delivery even if there are problems with the intermediate devices. A series of algorithm in routing determine the best path to route messages through the network.
You can apply filters to limit the propagation of messages based on certain characteristics (for example based on the sender or recipient) and automatically avoid phenomena of congestion.
What is Thingy:53 and how to implement Bluetooth mesh
The Thingy:53 platform by Nordic Semiconductor is a development solution that integrates a wide range of sensors and wireless capabilities into one compact device.
Thingy:53 uses a BLE module, supports Matter specifications which will be increasingly essential for devices for smart homeNFC, is open to machine learning and features 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 either by an internal battery or by an external power source.
It also uses an ARM Cortex-M33 based SoC capable of handling a high computational load without this negatively impacting the wireless connection.
A device like Thingy:53, which costs around 50-60 euros, can be easily integrated into different applications forInternet 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 configured for create a Bluetooth mesh network and thus adaptable to any project you may have in mind.
Nordic Semiconductor also provides a wealth of code examples and technical documentation to aid in the development of custom applications based on Thingy:53.
Ultimately, Bluetooth mesh and a product like Thingy:53 are especially useful for applications where you need to communicate with a large number of devices, such as in theautomationnell’lighting intelligent and in the systems of industrial control.
With the ability to build robust and scalable networks, Bluetooth mesh and Thingy:53 let you develop IoT solutions advanced and complex.