Bluetooth® released a Mesh Version in 2017. It is an own standard and strictly speaking not part of the Bluetooth standard. It uses Bluetooth® Low Energy link layer and radio and prefers Bluetooth® 5.0 or newer due to long advertising packets. As a flooding Mesh it includes time to live (TTL) in the messages. Security is approved by application key and network key.
How does it work?
The Network has nodes with different features. A node sends and receives data. Additionally there are relay nodes forwarding defined data. Special Low Power nodes are rarely active and only then send/receive data. The corresponding node is the Friend collecting data for the Low Power node. Only Low Power Nodes can be operated, since other nodes permanently receive and relay data. Bluetooth® Low Energy devices (i.e. smart phones) can connect temporarily to push/pull data to/ from the network. Nodes have to subscribe to groups to receive messages and publish to groups to transmit messages.
Bluetooth® Mesh Models define basic functionality of nodes on a mesh network. Mesh Profile Specification defines foundation models used to configure and manage the network. Mesh Model Specification includes models defining functionality that is standard across device types. Those Models are: Generics (general functions), Timing, Lighting and Sensors.
Is a Bluetooth® Mesh the best Solution for my Scenario?
To sum it up, there are the following benefits and penalties in using Bluetooth® Mesh, which has to be considered:
+ Extending the range by repeating messages, a self-healing network as there is the possibily of different routes of the messages make the Bluetooth® Mesh very useful.
- On the other hand it must be mentioned, that the performance of a Bluetooth® Mesh is quite poor. You could send 30 Bytes per 100 ms leading to a throughput of 2400 bps. Further, the Network must be installed by the end user himself, so technical knowhow is recommended. Furthermore each node has to be added to the network and provided with authentification and encryption keys which could make it time-consuming for the user.
If you want to read more find here the whole Product Guide.