# Home Automation System Based on Intelligent Transducer Enablers
## 2 Related Work
### Home Automation Systems  
In the last few years, several relevant home automation systems have been proposed. For instance, in [24], the authors designed, implemented and tested a method for integrating different wireless technologies (ZigBee, Wi-Fi, GSM/GPRS) in heterogeneous home automation environments. This LabVIEW-based system uses wireless nodes that are distributed within an intelligent building, monitoring different ambient parameters (temperature, humidity, light) and controlling different subsystems (e.g., lighting or irrigation). ZigBee transceivers have been also used in [25], where the authors have oriented the architecture towards the construction of a home automation system based on intelligent power outlets. A complete remote security platform is proposed in [26]. The solution integrates several home automation technologies and uses EIB/KNX RF and ZigBee to communicate with in-home appliances. The authors also propose an IP-based communication protocol between the home automation controller and the rest of the equipment. The platform can be controlled by remote security providers and homeowners through the Internet, via secure and efficient communication protocols. In [27], the authors propose a home network formed by sensors and actuators that control and obtain information from the home environment. The user interface is a low-cost Android tablet, while the controller is an Arduino board that offers connectivity with the electronic devices of the home network. The system uses both ZigBee and X10: ZigBee ensures the reliability of the system, while X10 allows for the integration of low cost controllers to optimize the overall cost of the system. Android is at the core of the system presented in [28]. A smart home application communicates with mobile devices with a micro web-server via the Internet using a Representational State Transfer (REST)-based web service. Wi-Fi or a 3G/4G connection can be used to connect the user device to the Internet. The system integrates elements such as light switches, power plugs and temperature sensors. The authors tested the system considering several home operations (e.g., remote switching, automatic environmental control or intrusion detection). The authors in [29] present CONDE, proposing a decentralized approach for decision and control for smart building applications. Compared to traditional centralized systems, response time and power consumption are both reduced. The tests performed using HVAC and lighting systems obtained lower decision delay times and better energy saving values than other alternatives compared. \begin{table}
\begin{tabular}{l c c c c} \hline \hline  & **Frequency Band** & **Data Rate** & **Max. Nodes** & **Wired/Wireless** \\ \hline UPB & 4–40 KHz & 480 bits/s & 64,000 & Wired \\ X10 & 433 MHz (EU) & 20 bit/s & 256 & Wired \\ EIB/KNXRF & 868 MHz & 16.4 kbit/s & 256 per line & Wireless \\ Z-Wave & 868 MHz (EU) & 9.6 kbit/s & 232 & Wireless \\ nanoNET & 2.4 GHz & 2 Mbit/s & 24  & Wireless \\ EnOcean & 868 MHz (EU) & 120 kbit/s & 2  & Wireless \\ IEEE 802.15.4/ZigBee & 868 MHz (EU), 2.4 GHz & 20–250 kbit/s & 65,536 & Wireless \\ IEEE 802.15.4/6 LoWPAN & 868/915 MHz, 2.4 GHz & 100–250 kbit/s & - & Wireless \\ IEEE 802.11 ah/Wi-Fi HaLow & 900 MHz & 18 Mbit/s & - & Wireless \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of relevant home automation communication protocols. Finally, it is worth mentioning the paper in [30], which analyzes the evolution of home automation systems towards IoT. The authors conclude that no commercial solution based on such a kind of system is easily applicable to the concept of IoT. Therefore, currently, it is necessary to translate the different protocols to IP, with the extra cost and overhead that such a process entails. Furthermore, it is emphasized that home automation technologies usually make use of dedicated and proprietary communication buses, requiring the use of proprietary end-nodes (i.e., sensors, actuators) and protocols.