It is said that almost everyone in the world knows about Bluetooth, at least by its symbol. Interestingly, this technology took off the wire that connected many devices in the last decade going completely wireless. Today after 20 years in service, the Bluetooth SIG team feels even more excited about the road it has taken for creating the Bluetooth MESH technology. This packet-based protocol is already being deployed to support smart concepts such as buildings, commercial lighting solution, and HVAC automation. This article is written based on the insights given by Martin Woolley, Technical Programme Manager for the EMEA region, Bluetooth SIG.
Bluetooth was initially called short link radio technology and later renamed to Bluetooth. The purpose of Bluetooth was to link up wireless headsets in the initial days which gained a lot of popularity in the music industry. Bluetooth still remains to be an unlicensed technology so that it could be used for all industrial, medical and scientific purposes. Essentially, it works on the frequency hopping spread spectrum which means, it performs 800 hops per second to relay the message packets. An extension to this is the Bluetooth low energy known as BLE which can accommodate 40 channels and works at 2 MHz spacing. Now the intriguing question that remains is how this technology could be used to build smart lighting systems in building and building smart cities of the future?
The Invisible Serial cable
After the release of the Bluetooth true flavor, the Bluetooth Basic Rate/ Enhanced Data Rate; it grew to become the most preferred technology for wireless audio devices. Reason being it keeps one free from tangled wires and hazards of broken wires. If you see now, Bluetooth has more advantages compared to the internet with Bluetooth Low energy. It is philosophically similar but quite different in the technical perspective from the classic Bluetooth.
Connectivity could be leveraged to connect more than one device unlike the one to one master-slave paired connectivity. A Bluetooth mesh can connect multiple devices. “Mesh networks have thousands of devices and communication could be done and not restricted to limited devices within a range of 100 meters”, says Martin Wooley. They can broadcast packets in this ‘point to point’ topology.
With this enhancement, experts have realized that Bluetooth could have a range of new applications similar to the Internet of things. The Bluetooth mesh protocol stack could be using BLE of Bluetooth low energy could be used to switch on your office light. The differentiator here is that BLE works in total isolation from other networks and perform the only specific task. More importantly, Bluetooth could be cost-effective than other hyped technologies to create a smart home in the segment considering it is a one-time installment.
BLE gives a wider range, consumes low energy and when connected they could be a great add-on to achieving energy standards of a building. For example, the lighting systems could be connected wirelessly, though it is technically challenging compared to the scale of a smart home. To surpass this challenge, the Bluetooth SIG team has created series of standardized models for specific purposes. For example, one network would only pair with the audio system while the other will be dedicated to smart lighting.
Dedicated use cases
The Bluetooth mesh can be set up anywhere. Office buildings, malls etc. The dedicated smart lighting systems could be designed to switch on and switch off based on the messages passed by the elements in the node in a Bluetooth mesh network. They are supported by models into which a set of values and behavior of a particular device are introduced based on sensors and lightings systems available in the building. The lighting systems on the endpoints subscribe to the data packets while the nodes publish messages. There are various automation models which automate lighting control based on timing and other controls based on data packets sent from nodes; essentially forming the basis of a smart lighting system based on Bluetooth mesh technology.
Comparably secure than IoT
Bluetooth mesh protocol stacks are not that easy to crack open. “Security is given a lot of emphases. Bluetooth makes security optional. The manufacturer has to decide what level of tech that is to be incorporated into their product. You can isolate areas and cryptographically separate BLE devices within the same hotel, though all the hotel rooms are separated from each other”, says Martin. All the messages are encrypted and authenticated with individual devices in the network, that is each of them is cryptographically different from each other. Similarly, addition and removal of devices from the Bluetooth mesh is also a secure process which makes it less vulnerable to external attacks and quite meaningless to attempt it either.
The significance of Bluetooth Mesh
Business across the globe are quickly adopting the cost-effective Bluetooth Mesh technology to automate entire shop floor. Clearly, this aims to provide a tremendous potential in the industrial field.The Bluetooth mesh will provide for more interoperability in the days to come which means it will continue to exist sharing its space with Internet-based connected ecosystem and may prove to be even better.
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