## 3 Communication Technologies and Wireless Sensors Networks
### Standards and Protocols
#### 3.2.2 Wireless Protocols
The modules are cost-effective and offer reliable connectivity through commercial LTE operators. These modules can incorporate sensors for measuring and transmitting data (uplink) or receiving data (downlink). In 3 GPP's release 13, the maximum data rates are set at 20 kbps for uplink and 100 kbps for downlink, with later releases significantly improving the uplink rate to 142.5 kbps [48]. Project [49] aims to develop a solution for the modernization and security enhancement of crucial water supply and purification systems within the scope of Industry 4.0 applications for smart cities. The focus is on assessing the renewal needs (and applicable use cases) and proposing an IoT-based solution for urban critical infrastructure. The paper outlines the IoT network architecture and specific hardware for securing water supply and wastewater treatment processes. Details include the water level control mechanism and a system ensuring optimal chemical levels for wastewater treatment. The selected technologies for revitalizing critical infrastructure via IoT networks are the NB-IoT protocol and the 4G mobile networks. NB-IoT effectively incorporates communication security protocols inherent in mobile networks, benefiting from the extensive deployment of 4G coverage, and the chosen deployment location is anticipated to have 4G coverage. Presently, the characteristics and requirements of IoT networks are adequately addressed using NB-IoT or LTE-M. However, the author notes that, as 5G protocols become standardized, the natural progression for IoT networks is to leverage the advantages provided by 5G. [PERSON]'s study [50] begins by clarifying that wireless sensor networks are described as the observation and management of physical phenomena along with mission-critical infrastructures, and subsequently presents research on deploying NB-IoT technology for industrial applications. It explores the practical aspects of setting up an NB-IoT test network, including different deployment testing using NB-IoT devices and an LTE/NB-IoT base station. The study focuses on the security requirements, power and latency performance, and global spectrum deployment options for a potential private licensed NB-IoT network. It highlights NB-IoT's advantages such as massive connectivity, good power utilization, long-distance transmission, and higher data throughput, particularly in 4G and 5G applications. * LoRaWAN  
LoRaWAN--a prominent LPWAN technology--has garnered substantial attention from the research community. Developed by Semtech Corporation, it facilitates long-range data transmission with low data rates. Using a chirp spread spectrum (CSS) modulation, where the chirp signal frequency varies, LoRaWAN ensures robust coverage. The modulation employs spreading factors (SFs) ranging from 7 to 12, with higher SFs providing better coverage but at the expense of data rate and power efficiency [51; 52]. Study [53] focuses on establishing a range of data transmission in diverse and challenging environments, along with identifying the key radio parameters influencing this transmission. The findings guide the application of LoRaWAN in critical infrastructures by specifying the circumstances and methods suitable for implementation. The study conducted a comparative analysis of LoRaWAN communication in an urban prefabricated environment, emphasizing its applicability in critical infrastructures like residential areas, industrial plants, sewage treatment plants, and hospitals. The results affirmed the high reliability of LoRaWAN in such setups, demonstrating sufficient coverage in Budapest for critical infrastructure protection (CIP) applications. Mobile measurements revealed that LoRaWAN could function seamlessly, even on public transport. Jammer interference measurements indicated minimal disruption, emphasizing the stability of LoRa communication. Safe box measurements exhibited positive outcomes, displaying LoRa's suitability for secure structures like containers or safety deposit boxes.