## 5 Discussion of the Case Study--Rwanda  
Rwanda is an eastern African country with a fast-growing economy. Its cities have been gradually expanding, with 881,445 city dwellers in its largest cities and 8,169,341 in rural areas [40]. Increasing urban populations have also led to increasing risk of fire. There is a high risk of fire outbreak due to new public construction, combined with a lack of firefighting equipment and sufficient people to operate it. Over the last 10 years, fire outbreaks have increased, with 327 fires registered across the country since 2010. Public buildings include shops and higher learning institutions, holding a huge number of people. The case study taken used for this research was from the University of Rwanda, College of Science and Technology, Kalisimbi Block, where the research was conducted and deployed. Table 3 summarizes fire incidents recorded from 2010 to 2019. A national inquiry, set up to investigate the causes of the fire outbreaks, found that 61% of fire incidents were due to short circuits, while 22% were due to unknown causes [41]. Additionally, 9% were argon, 4% were caused by road incidents, 3% were caused by hazardous domestic activities, and 1% were caused by chemical explosion as shown in Figure 3.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Years** & **Alerts** & **Deaths** & **Injured** & **Houses Destroyed** & **Crops Ha** & **Liver-Stock** & **Churches** & **Admin Buildings** \\ \hline
2010 & 0 & 4 & 9 & 73 & 5 & 0 & 0 & 0 \\
2011 & 0 & 2 & 7 & 84 & 12 & 0 & 2 & 0 \\
2012 & 0 & 0 & 8 & 83 & 21 & 1 & 3 & 0 \\
2013 & 0 & 8 & 8 & 88 & 17 & 2 &  
Due to the aforementioned fire outbreaks, there was a need to address the issue by incorporating an IoT solution. Some research proposed the implementation of IoT techniques for early warning and notification, but the solution was limited by system escalation and modular reusability [42]. Many applications of IoT focus on the smart health care domain [43]; however, this research proposed IoT frameworks applied in smart buildings with the following capabilities: reusability, scalability, accessibility, interoperability, and updateability. Referring to the sensor node deployment shown in Figure 4, temperature, humidity, and CO\({}_{2}\) sensors were connected in the middle of the room to maximize capture. A proximity sensor was deployed at the entry point of the room. The reason for choosing this configuration was to be sure that any captured positive value would show the moving being. The last parameter of interest was the counting of entries using two communicating infrared sensors (IR). The presence of a moving object in the office would not necessarily mean that it was a human being. All of those sensors in combination would help to improve the questions asked in [44], for instance, to recognize the presence of humans if there were a moving chair during an earthquake. The management of the architecture used a distributed set of identical IoT devices deployed in different locations. Each device was configured to be part of the same group. Figure 4: Sensor Deployment architecture in UR, Kalisimbi Block offices. Figure 3: Fire outbreak causes. Every time a new device was turned on or connected, there were different steps to follow:  
- A New IoT device, such as a sensor or sensor node, is connected to the manager. - The connected device/sensor is identified with its unique identification. - The manager assigns the device to the device group, meaning the floor coverage of the building. - The latest device group configurations are pulled. - The manager checks for any updates from the broker (manager) map table to update the connected groups. Any time the admin deployed a new device or changed existing device configurations, the following steps were to be followed:  
- Push a new container version, with its corresponding tags, into the configured Docker registry. 1. Update the control API. 2. Update the backend database with the new configuration. 3. Update all connected IoT devices in their respective groups.