12 April, 2023 - In this post we describe how we have solved the waste management in containers, for large surfaces, in a Smartcity by using LoRaWAN networks. These communication networks are making their way into our projects. They are doing so quietly, but continuously and consistently. There are more and more use cases using this technology. This should come as no surprise, as we have already seen the emergence of WiFis some time ago.
The trick is always the same, a small spectrum is left free (without a license) for the development of new services. Different actors start to play with it, then when one appears that creates a recognisable added value, an ecosystem of innovators is created and then the market recognises the opportunity. This is what has happened with LoRaWAN technology, developed by the company Semtech, around which the LoRa Alliance has developed.
There are other technologies (LPWAN: Low Power WAN) that also try to use the same frequencies that do not require a licence (in Europe usually from 863 to 870 MHz), but the LoRaWAN ecosystem is the most complete on the market. There are even satellite operators already using this technology, and in recent weeks we have learned that Amazon has deployed a network (Sidewalk) throughout the USA by activating the LoRaWAN module in the Echoes they sell in that market. It is to be expected that this network will also be activated in Europe in the near future. Now it turns out that Amazon wants to become an IoT network provider ... While national operators and global LoRaWAN networks already exist, Amazon's could be disruptive...
It seems that despite all the efforts that operators are making with NB-IoT, LoRaWAN will coexist with them, as it enables low-speed send/receive data services, with almost no OPEX (no need to pay for SIMs from operators) and sensor batteries easily last 10 years.
This is not to say that the deployment of these solutions is without challenges, but when there is a strong ecosystem, improvements are proposed, such as the recent LBT (Listen Before Talk :-) functionality for optimising the use of communications channels.
In this scenario, a use case that fits very well with this technology is the management of waste containers in buildings, Smartcities, civil works and industrial environments.
For this, sensors are installed that analyse the waste status and occupancy of the bins. These sensors are then connected to a nearby gateway (acting as a concentrator), which for a Smartcity can be kilometres away depending on the coverage. From there, the waste data is sent to the client's management platform, either by wired or wireless connection (e.g. 4G).
One of the great advantages of this solution is that information is only sent when it is necessary (e.g. when a waste container is at 70%), this greatly reduces consumption and battery autonomy of more than 5 years can be achieved.
We will start by describing the functionalities we have taken into account for waste management in the containers:
- Motion stop
- Fill level detection
- Temperature detection
- Humidity detection
- Autonomy of more than 5 years
- IP67 protection
In the end the solution we have considered is composed of two sensors: One for the detection of the movement, by means of a three-axis accelerometer (X,Y,Z) and a dual ultrasonic sensor, for the detection of the filling level, and the second one for the detection of the temperature and humidity.
Both sensors are installed on top of each container and will be connected via radio (LoRaWAN) to a Gateway acting as a concentrator.
For this project we have considered a configuration of our IoT Node as a LoRaWAN Gateway. This allows us to re-route the traffic from the sensors via ethernet network (wired or fibre) or via 4G. Furthermore, the use of an IoT Node that supports open architecture and is compatible with UNE 178104 & UNE 178108, allows the integration of the data from the container sensors with other types of information from the Smartcity, nearby buildings or industries (e.g. environmental, weather and/or volume of people around). In this way it would be possible to set criteria for waste collection beyond how full the containers are.
In the picture below you can see our IoT node with the LoRaWAN board installed in one of the available slots. There are two other slots left, one to be used for those locations that need 4G access and the other slot is available for possible future expansion.
Regarding the SW stacks, in this case we have installed Ubuntu as the O.S. in the IoT Node and Semtech's "packet forwarded" for the board we have selected (based on the SX1303 and with Listen Before Talk functionality). Then, we have two options for managing the sensor data. Either send them to a general platform in the cloud (e.g. The Things Network) or, if we want something more customised, integrate them into the Resiot.io platform that also runs on our IoT Node. In the latter case, we can create customised dashboards and control logics with the sensor data, locally on the IoT Node itself.
