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 a 1 Mbit/s PHY bit rate on the LE 1M PHY; effective Mesh network throughput is substantially lower because of advertising overhead and relay mechanisms

• LE Coded PHY may be used for extended range (optional)

Bluetooth Mesh transports messages over the advertising bearer or the GATT bearer; the latter uses the Proxy protocol over a GATT connection.

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

Nodes that support the optional Relay feature and are configured accordingly can forward messages 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

Bluetooth Mesh devices are assessed as Bluetooth LE radio equipment. The regulatory assessment considers the product's actual advertising behavior and the requirements applicable in the target market, including relevant transmit-time, duty-cycle, and power-density considerations.

Interoperability and correct implementation of roles and models are assessed separately through Bluetooth SIG qualification against the Mesh Profile Specification.