Bluetooth Mesh
Bluetooth Mesh is a wireless networking protocol built on top of Bluetooth Low Energy (LE). Introduced in 2017 by the Bluetooth SIG, it enables many-to-many (m:m) communication between devices and is designed for large-scale device networks, such as building automation and smart lighting systems.
Frequency & Modulation
Since Bluetooth Mesh is based on Bluetooth LE, it operates in the 2.4 GHz ISM band using GFSK modulation. The physical layer parameters remain the same as LE:
40 channels (2 MHz each), including advertising and data channels
GFSK modulation with typical data rates of 1 Mbit/s
LE Coded PHY may be used for extended range (optional)
Mesh networking makes use of BLE advertising packets, primarily through the advertising bearer rather than traditional connections.
Typical Applications
Bluetooth Mesh is ideal for scenarios where large numbers of devices need to communicate reliably across wide areas:
Smart lighting systems
Building automation (e.g., HVAC, access control)
Industrial monitoring
Retail and asset tracking
Each device in a Mesh network can act as a relay, forwarding messages to other nodes using a managed flood approach.
Differences from Bluetooth LE
Bluetooth Mesh is not a separate radio standard but an upper-layer protocol that extends Bluetooth LE with network capabilities. Key differences:
Many-to-many communication instead of point-to-point
Message relaying between nodes for extended range
Strict role definitions (e.g., relay, proxy, friend, low-power node)
Defined models for device functionality and secure provisioning
It does not use standard GATT-based connections but relies on broadcasting.
Relevance for Testing & Certification
From a regulatory perspective, Bluetooth Mesh devices are tested as BLE radios using the same frequency range and modulation schemes. However, additional evaluation may be required for:
Continuous advertising behavior
Duty cycle and power density
Interoperability and role implementation
Mesh functionality is also subject to Bluetooth SIG qualification, including compliance with the Mesh Profile Specification and model definitions.