# The Use of Wireless Networks and Mobile Applications in the Control of Electric Machines
## 1 Introduction  
Nowadays, the Internet has covered almost all disciplines of modern life [1; 2; 3; 4] and wirelessly controlled devices have become more and more popular. Currently, almost every person is equipped with a mobile device that can act as a user interface for controlling other objects [5; 6; 7]. Wireless communication, which is now inextricably linked with mobile devices, is relatively cheap and readily available. We live in the era of the Internet of Things (IoT), a global intelligent network which has developed expeditiously over the last twenty years simultaneously with advances occurrence in networking technologies, including Bluetooth, Wi-Fi, and long-term evolution (LTE) [8]. The IoT is the strategy of extending Internet connectivity beyond standard electronic devices, such as laptops and smartphones, to any type of household appliances, for instance, fridges, washing machines, ovens [3; 9] and creates an opportunity to manage processes from the level of a mobile application. Smart applications could serve people and provide them with support in intelligence systems such as transportation, healthcare, smart agriculture, smart houses, smart cities and smart grids [10]. A smart grid is characterized by the capability of two-way communication of both electricity and data [11]. This is based on communication technologies and advanced metering infrastructure which enables monitoring, controlling and reacting to unexpected and unpredictable changes in the power system. Recently, the number of processes and devices which are monitored and controlled remotely has been increasing. One of the possibilities to control a device in such a way is the use of a mobile device that provides a specific type of wireless communication like Wi-Fi or Bluetooth, and a graphical interface in the form of a mobile application. It is observed that mobile application development for smartphones has evolved vastly due to ubiquity andpopularity among end users who are using them more than ever. This fact has resulted, however, in developers' focus on the improvement of users' experience to the detriment of security [5; 12]. Since the remote control of household devices is no longer a problem, the applicability of mobile devices with wireless transmission to control industrial automation devices, such as electric drives, seems to be also achievable. However, this is more demanding due to the need for ensuring greater requirements for the safety and reliability of the control process. Remote control, in particular one that uses wireless technology to transmit signals, allows maintaining a safe distance from a device under operation. In addition, the use of microcontrollers enables the collecting and sending data from sensors of various types, for instance, temperature or humidity, in a dispersed manner. What is more, remote control reduces costs and improves control efficiency by reducing the number of wires and eliminating the problem of their arrangement. Nevertheless, wireless transmissions are not devoided of disadvantages. In particular, they are exposed to the influence of external factors, which are mainly other radio systems or electromagnetic disturbances of various origins, or disturbances from converter systems in case of industrial conditions. Among the various categories of mobile applications, such as online games and social networks, there are also critical ones that could guarantee a high level of reliability and quality [13; 14]. From this point of view, a mobile application can be considered as one of the most relevant elements of the entire control system, as the application's interface is what the user has direct contact with. The properties of the application also determine the attending of a system to some extent. The safety of the operator and the device under control from the level of such an application often depends on whether it is written in accordance with the accepted standards and on its ergonomics.