Whitepapers

AUGMENTING BACnet WITH LoRaWAN ® WIRELESS IOT www.lora-alliance.org There are two elements, or layers, to the way these devices communicate. The long-range technology element or 'lower' layer is a low frequency radio protocol, called LoRa, that allows communication over long distances and in very 'noisy' radio environments where other devices would struggle with interference. The 'upper' layer is the openly specified LoRaWAN communication protocol, which manages the power load as well as how the system networks and what frequencies it uses. Like a cordless phone or garage door remote, these devices do not require any license to deploy and operate. LoRaWAN is not a replacement, but an augmentation to the BACnet environment. It can integrate into that environment in several different ways thus freeing the building manager to collect data from sources never dreamed possible even a few years ago. PUTTING LoRaWAN TO WORK New technologies have to live with legacy systems. We saw that many organizations have BACnet control systems up and running, with hardware built around the BACnet technology. The question then is how best to use the flexibility and rapid build-out potential of LoRaWAN in the context of an existing installation. A typical company may want to use many of the specific capabilities of the LoRaWAN technology – like the ability to manage changing patterns of room or desk occupancy, or direct interaction with building users – and add this value to an existing BACnet system. And, in the wake of the Covid-19 pandemic, organizations are under intense pressure to make their buildings smarter and to manage the impact of building use on health and wellbeing, as well as to be a lot more flexible about working space provision. LoRaWAN opens up pathways to achieve that – but in most cases that means working with the buildings control legacy rather than attempting to replace it. Experience has shown that there are several ways forward when it comes to combining LoRaWAN flexibility to a BACnet infrastructure. And three of these have already been deployed. The first option is the backhaul option, and it focuses on the way data are channelled. Also known as 'BACnet over LoRaWAN', it makes LoRaWAN the communications link to whatever control applications are needed. It requires no change related to the BACnet protocol, network or BACnet enabled devices and management systems. The second route is the complementary network option, focusing on integration at the Building Management System (BMS). The readout from IoT devices is presented to the BMS via an API, so that LoRaWAN data and sensors still appear to be part of the legacy BACnet system. And there is a third option, which focuses on analytics. Instead of integrating LoRaWAN and BACnet at the buildings and control level, the data streams from both technologies are kept separate until they reach the stage of the analytics engine. Case Study: Wattsense/Setemi LoRaWAN IS COST-EFFECTIVE FOR ANY BUILDING SIZE A large majority of small and medium-sized buildings (less than 5,000 m²) are not equipped with Building Management Systems due to the high cost of installing technically complex systems. This is a problem that LoRaWAN implementations can solve. The French facility management company Setemi needed to install a BMS in a mid-sized 190-unit condominium, and turned to the French communications and controls specialist Wattsense for a solution that could handle multiple device control protocols, including LoRaWAN. The aim was to connect BMS equipment to the Setemi web-based energy management platform, while minimising site visits by technical staff. Wattsense installed its own remotely controlled IoT box to capture data from pumps, boilers, heating regulators and a gas meter fitted with a LoRaWAN device, which in turn are controlled by the Setemi energy management system. The installation was up and running in less than a day, giving remote access to the gas meter and the heating regulator's parameters, and the capability to control all the BMS devices remotely. This solution is interoperable with multiple devices and protocols, quick and cost-effective to deploy, and cheap to maintain over time. That means full- featured management systems are now within reach for smaller buildings.

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