# On the Use of LoRa Technology for Logic Selectivity in MV Distribution Networks
## 4 Enabling Technologies for Logic Selectivity
However, this solution is expensive and presents a problem if the support of the overhead power line falls; in such a case, the fiber is unusable and can be damaged, requiring a replacement of the cable. Different wired solutions, Ethernet cable, for example, are characterized by the same installation problems [28]. An alternative that reduces installation costs is represented by the Power Line Communication (PLC) technology which allows the message exchange to occur using the same cables that carry electricity. However, the communication ranges of the PLC are limited to 400 m for high transmission speeds and 800 m for low speeds; so, for secondary substations placed at greater distances, it is necessary to provide an apparatus that acts as bridge [29]. In regard to transformers and circuit breakers that can isolate sections of line or entire zones, it is necessary to install bypass devices that assure a continuity in communication service [30]. Moreover, in a modern smart grid, this communication technology could be undermined by changes in the network topology [31]. To overcome the problems related to the installation of wired communication networks, some researchers have moved toward wireless communication technologies. In this case, there are different technological solutions operating in either licensed or free frequency bands [32]. In the first case, the network infrastructure is owned by telecommunications companies, and the electricity companies must not incur any costs for its construction and maintenance. In fact, taking advantage of the mobile phone network to make connections between the electrical substations, only the costs related to the purchase of wireless devices and those of subscription to the offered services should be supported, the amount of which depends on GSM, 3G, 4G, or LTE-M adopted technology. However, in this scenario, the communication network will never be owned by the electricity company and the availability of the service depends on the quality guaranteed by telephone companies, signal coverage, mobile traffic, etc. The other solution is instead to use the free communication frequencies in the Industrial, Scientific, and Medical (ISM) band to create a proprietary wireless communication network between electrical substations. These include the application of extended WiFi, which is part of the Wireless Local Area Network (WLAN) technology, offering a communication range limited to a few hundred meters. In addition, the typical consumption of WiFi devices requires a mains power supply, so, in the event of a failure, a backup power supply must be guaranteed. In [33], the results obtained by adopting this technology for the transmission of messages compliant with the IEC 61850 standard [34], limited to two apparatuses placed only 75 m apart from each other, are presented. Recently, a new communication technology, referred to as LoRa (Long Range), has been introduced. LoRa operates in the free band [35] and is rapidly spreading as an enabling technology for the Internet of Things (IoT). LoRa technology allows considerable communication distances (up to 15 km in rural environments) to be reached with very low power consumption and is, therefore, particularly suitable for use in embedded sensor networks where low bit rates are sufficient, hardware resources are limited, and battery saving is required. Examples of applications of LoRa technology can now be found in industry, logistics, environmental monitoring, smart city applications, smart agriculture, etc. [36].