# Rapidly Deployable IoT Architecture with Data Security: Implementation and Experimental Evaluation
## 2 Related Works
### IoT System Architecture  
Monitoring of building occupancy and environment is essential for fault detection, intelligent control, and building commissioning. Although there are many solutions for environmental monitoring, they are time-consuming and require technical knowledge to set up. The three applications implemented in this paper represent environmental sensing solutions in different scenarios. These sensor platformsgather information from their surroundings, feed the data to the wireless transceivers through the first layer of the modular architecture discussed later in this section. Although some wireless transceivers were equipped with standard security protocols, not all transmit encrypted data. The raw data can be accessed between a wireless transceiver and gateway device, jeopardizing privacy and security. This paper adds an intermediate layer of security between the information collector node and wireless transceiver layer, which is nonexistent in most literature and consumer products so that raw data cannot be easily accessed remotely, even if the wireless transceiver does not have any encryption features. This section briefly describes the state-of-the-art literature on such platforms to provide an insight into how researchers investigate the efficacy of such devices and tuning of parameters that ameliorate the performance and usability of sensor platforms. Building-in-Briefcase (BiB) [39] is a portable sensor network platform that addresses issues such as portability, accessibility, and scalability. The distributed sensor network collects environmental data, sends the data to a router using a TCP/IP protocol and Wi-Fi, the router sends the data to the central database over the internet using 3G connectivity. The data can be viewed on a web portal in real time. The BiB sensors are connected to the router using standard wireless 802.11 b/g technology secured with WPA2. The radio used to transfer the sensor data to the router wirelessly is Roving Networks' RN-XV. It consumes 10x more power than Bluetooth or IEEE 802.15.4 products, but the high data rate allows for the transmission of large data packets in one burst, which they claim are more power efficient. WE-Safe [40] is a real-time, low power wearable sensor node platform that supports multiple environmental sensors and is aimed at monitoring harmful gases and elements such as carbon monoxide, carbon dioxide, particulate matter, and ultraviolet rays. The sensor node uses the Long Range (LoRa) based gateway to establish communication between the environmental sensors and the cloud. In [41], the authors proposed a Raspberry Pi based portable tour guide system, which gives personalized, localized audio-visual information to tourists to improve user-experience and increase tour efficiency. This handheld portable tour guide system uses iBeacon for localization and RFID technology to detect specific objects such as artifacts in museums. The iBeacons are placed at specific locations and send advertising packets periodically containing its universally unique identifier (UUID). The Wi-Fi enabled Raspberry Pi in the tour guide device measures the received signal strength identifier (RSSI) of the iBeacons to find out the tourist's location. The location of the tourists and the identity of the objects are uploaded to a cloud service, which sends uniform resource locators (URLs) of a video to the handheld tour guide device providing detailed information about the object. [PERSON] et al. presented a wireless environmental monitoring system for greenhouses in [42], where the system is divided into three functional units. The sensor unit and the coordinator units are C8051F020 microcontrollers and communicate with each other via Zigbee wireless technology. From these studies, it is evident that the breadth of IoT applications is broad, but the connectivity and overall system architecture is fundamentally similar even though the hardware utilized varies based on the application.