1Bluetooth Mesh 2-------------- 3 4.. toctree:: 5 :hidden: 6 :titlesonly: 7 8 sample 9 10.. contents:: 11 :local: 12 :depth: 2 13 14Introduction to Mesh 15~~~~~~~~~~~~~~~~~~~~ 16 17Bluetooth Mesh is a new standard from Bluetooth SIG that was released in 2017. It enables many-to-many device 18communication (as opposed to point-to-point approach in BLE) and is optimised for large-scale networks like building 19automation or sensors network. It utilizes managed flood based approach where only mains-powered nodes relay messages 20making it very power efficient (battery powered low-power nodes that don't relay messages can operate in mesh network for years). 21 22Bluetooth Mesh is complementary to Bluetooth specification and requires features from 4.0 release only. This allows 23deployment of networks using hardware already available on the market. 24 25Topology 26~~~~~~~~ 27 28.. figure:: mesh_topology.jpg 29 :alt: Bluetooth Mesh Topology (source: Mesh Profile Specification 1.0) 30 31Bluetooth Mesh defines few features (roles) for devices in network. Those are: 32 33- Relay - receive and retransmit mesh messages over the advertising bearer to enable larger networks 34- Proxy - receive and retransmit mesh messages between GATT and advertising bearers. 35- Low Power - operate within a mesh network at significantly reduced receiver duty cycles only in conjunction with a 36 node supporting the Friend feature 37- Friend - the ability to help a node supporting the Low Power feature to operate by storing messages destined for those nodes 38 39Bearers 40~~~~~~~ 41 42Mesh Profile specification allows two kinds of bearers for transmitting data: 43 44- Advertising Bearer 45 46 - Uses LE advertising to broadcast messages to all nodes that are listening at this time 47 - Uses non-connectable advertising only 48 - 29 octets of network message 49 50- GATT Bearer 51 52 - Uses LE Connections to send messages 53 - Uses standard GATT service (one for Provisioning and one for Proxy) 54 55Provisioning 56~~~~~~~~~~~~ 57 58Provisioning is a process of adding an unprovisioned device to a mesh network managed by a Provisioner. A Provisioner 59provides the unprovisioned device with provisioning data that allows it to become a mesh node (network key, current IV 60index and unicast address). A Provisioner is typically a smart phone or other mobile computing device. 61 62Models 63~~~~~~ 64 65Models define basic functionality of nodes on a mesh network. Mesh Profile Specification defines foundation models used 66to configure and manage network. Mesh Model Specification includes models defininig functionality that is standard 67across device types. Those consists of: 68 69- Generics - root models 70 71 - On/Off 72 - Level 73 - Battery Server 74 - Location 75 - Client Property 76 - and others 77 78- Sensors - defines a standard way of interfacing with sensors 79- Time and Scenes - defines a set of functionalities related to time and saved states on devices 80- Lighting - defines a set functionalities related to lighting control 81 82Complex models e.g. Lighting may contain other models eg Generic On/Off. The following image shows an example of Light 83Lightness Server Model. 84 85.. figure:: mesh_lightning_model.jpg 86 :alt: Light Lightness Server model (source: Mesh Model Specification 1.0) 87 88Mesh Node features supported by Apache Mynewt 89~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 90 91- Advertising and GATT bearers 92- PB-GATT and PB-ADV provisioning 93- Foundation Models (server role) 94- Relay support 95- GATT Proxy 96
