Bluetooth Rolls Out Mesh Networking

BELLEVUE, WASH.—The developers of Bluetooth have incorporated the short-throw wireless transmission technology into mesh networking. With mesh networking, Bluetooth is no longer limited to its unaided range of around 100 meters, nor locked into device-to-device communication..

“The new mesh capability enables many-to-many device communications and is optimized for creating large-scale device networks,” wrote Ken Kolderup of Bluetooth on the company blog. “It is ideally suited for building automation, sensor networks, and other IoT solutions where tens, hundreds, or thousands of devices need to reliably and securely communicate with one another.”

The mesh technology works on Bluetooth Low Energy, or “LE,” which uses short-burst wireless connections on a one-to-one device basis, over a point-to-point network topology referred to in the Bluetooth core spec as a ‘piconet.’

In a mesh network, each device is able to communicate with any other device on the mesh so that information can be relayed from one to the next—or several simultaneously—over longer distances and larger areas. (Fig. 2, at right, is from Bluetooth’s “Mesh Technology Overview,” a downloadable .pdf.) Devices that are part of the mesh are referred to as “nodes.” Bluetooth devices become nodes through a provisioning process using a NetKey common to all devices on a specific mesh.

Unlike Wi-Fi, which relies on a central router, Bluetooth mesh uses a “managed flood” approach to message transmission. In managed flooding, messages created by a node are broadcast to all other nodes within radio range, rather than routed to specific nodes. The receiving nodes then broadcast the original message to other nodes and so forth, in a type of multipath daisy chain.

Smart-lighting company Silvair is on board. So is Wireless Cables, Inc., of Campbell, Calif., a maker of Bluetooth LE-enabled transmitters. Dr. Juergen Kienhoefer, CEO of Wireless Cables said, “Our customers are mostly industrial customers that work with sensors and controls, meaning they need long range, tight security, and reliable communication with a large number of devices, as well as more and more integrated web capabilities each year. While our current solutions can extend Bluetooth range up to 200 meters, Bluetooth mesh allows us to solve even more complex range and limit problems.”

And again, Kolderup, with some ABI Research numbers about the growth forecast for IoT devices.

“The introduction of Bluetooth mesh networking comes at a time of pivotal industry growth, with ABI Research expecting 48 billion internet-enabled devices to be installed by 2021, of which nearly one-third will include Bluetooth. We expect Bluetooth mesh will make the largest initial impact in commercial lighting and industrial applications, and will eventually become a common technology in the larger Internet of Things ecosystem.”