Concurrent multicast in large-scale networks
Bluetooth mesh is a state-of-the-art mesh networking technology that extends the capabilities of Bluetooth Low Energy. It enables powerful concurrent multicast (many-to-many) communication in networks with thousands of nodes. The functionality is a vital update for new applications in lighting, sensor networking, predictive maintenance, asset tracking and positioning.
Bluetooth mesh is a managed flooding mesh, which is a simple and reliable approach to distribute messages in larger networks. Reliability is ensured with multiple paths from source to destination and there is no single point of failure. The technology has separate encryption for network and application layers, and has protection against different types of attacks.
Introduction to Bluetooth mesh
On-Demand webinar
Introduction to Bluetooth mesh
Topology and roles
Bluetooth mesh uses Bluetooth Low Energy as bearer or transport for its messages. The Bluetooth mesh messages are encapsulated in either Bluetooth LE advertisements or GATT packets, referred to as advertising bearer or GATT bearer (connections). Normal nodes typically use the advertising bearer, but when a smartphone connects into the network it typically uses the GATT bearer. The smartphone connects to one node and then that node relays the messages into the network.
The below figure shows an overview of the Bluetooth mesh roles:
- N: Node is the most basic role. It uses the advertising bearer only and its receiver is always on. It will not retransmit messages.
- RN: Relay node uses the advertising bearer only and its receiver is always on when not retransmitting messages. It extends the network range and allows messages to hop between multiple relay nodes.
- P: Proxy node has the same functionality as a RN, but can also use the GATT bearer to connect to for example a smart phone. It runs the Bluetooth mesh stack and the Bluetooth LE stack.
- FN: Friend node has the same functionality as a RN, but can establish a friendship with one or more LPNs. It will store messages for the LPNs it has a friendship with.
- LPN: Low power node uses the advertising bearer and its receiver is mostly turned off. It wakes up at a certain interval and polls for messages from its Friend node. It can wake up at any time to send a message to the network.
- GATT connectivity represents a node that connects to a Proxy node over a GATT connection using either Long Range, 1 Mbps, or 2 Mbps.
If you want to learn more about Bluetooth mesh we recommend reading the Bluetooth mesh concept section and also the "Mesh Profile" specification.