# Home Automation System Based on Intelligent Transducer Enablers
## 1 Introduction  
The Internet of Things (IoT) paradigm refers to a global dynamic infrastructure based on interoperable communication protocols that integrate physical and virtual objects into an information network. The remarkably rapid growth of inexpensive and tiny computing devices, endowed with sensing and communication capabilities, is paving the way for the success of the IoT in almost any field. Nowadays, IoT offers a large number of opportunities for engineers, manufacturers, software developers, marketers and investors [1; 2]. Among other applications, home automation or smart homes are rapidly gaining interest. Home automation systems are focused on improving the interaction with devices and appliances typically found indoors [3; 4; 5]. The aim of such systems is to make the home environment comfortable and accessible, automating and optimizing the use of appliances, like TV sets, air conditioners, light bulbs, ovens or washing machines. For example, a home automation system might be able to modify the intensity of a light bulb through a smartphone, to monitor smoke detectors, to send alerts related to the home security system or to automatically adjust an air conditioner to set the optimal temperature. Moreover, technologies like Bluetooth Low Energy (BLE) allow home automation systems to identify and track the presence of a specific user, making automatic adjustments to adapt the environment according to the user location and personal preferences. This interconnected ecosystem of devices would be able to offer value-added services and benefits, such as efficient energy management, environmental control, remote monitoring, reduced operational costs, security and safety. In IoT, each device must be addressed individually. Such an identification is usually carried out through an Internet Protocol address (IP address), which allows devices to be accessible over the Internet. Many standards and proprietary communications interfaces (e.g., Wi-Fi, Bluetooth, ZigBee, RFID, Z-Wave) can be used for connecting things to each other or to a cloud. The technology selected is usually determined by the physical characteristics of the environment, sensor density, desired range and the data rates required. Among the different technologies, Wi-Fi has been presented as one of the most promising choices for future IoT developments, since it has certain characteristics commonly associated with IoT: low cost, relatively low power, compact form factor and the ability to create scalable deployments. This tendency is reflected in the approval of the IEEE 802.11s standard [6], which allows an IEEE 802.11 WLAN to be deployed as a mesh network. Many well-established automation systems are based on wired communications, where the system must be planned in advance and installed during the physical construction of the building. For already existing buildings, such kinds of wired deployments are usually more expensive, since they require altering the internal decorations, modifying electrical wiring and installing communication devices. Wireless solutions tackle such issues, reducing installation costs and making home automation easier to scale. Home automation applications generally need a central control system to manage the configuration and interaction with transducers (i.e., sensors and actuators). The operation of such kinds of systems poses several issues that should be solved. The main problem is related to scalability, since a single network usually connects a large number of transducers. Furthermore, all transducers would have to be able to communicate with each other and with the control system, which might derive interoperability issues due to the heterogeneity of the sensors and actuators included. These problems become worse when the sensor network is deployed in an environment that was not originally designed for home automation.