## 4 Substation
### Sensor and Metering Technologies  
Over time, the need to share information has propelled human activity, influencing how the economy and technology have developed in society [82]. The accuracy and reliability of data acquisition are paramount in ADNs. Sensor and measurement technologies, such as smart meters, phasor measurement units (PMUs), and synchrophasors should be explored. It underscores how these technologies contribute to situational awareness, fault detection, and grid optimization [83]. Notably, data exchange between sensors, controllers, and actuators becomes of vital significance, affecting measurement precision and the potential for stable control of an industrial process. ADNs have witnessed a remarkable transformation in recent years, driven by the increasing penetration of renewable energy sources and the need for improved grid management. Smart metering infrastructure (SMI) has emerged as a foundational technology for enabling control and automation functionalities within ADNs. This point critically examines the key enabling technologies associated with the implementation of control and automation functionalities in ADNs, with a specific focus on SMI.  
\begin{table}
\begin{tabular}{c l l l} \hline
**Authors** & \multicolumn{2}{c}{**Thereats/Security Concerns**} & \multicolumn{2}{c}{**Mitigation Measures**} \\ \hline
[56,84] & Lack of real-time scheduling in high availability seamless redundancy (HSR) affects traffic jitters, especially during a high flow of SMVs that share an HSR ring. This leads to network congestion or stoppage. & The use of the quick removing (QR) approach to remove duplicated frame copies from the network when all nodes have received one copy of the sent frame [84] \\ \hline
[73] & Generation of interfering signals and high frequency leading to loss of metering and control data & Improve compatibility between EN 50160 and IEC T5 62749 [85] \\ \hline
[74] & Alternation of substation operations by modifying and falsifying information/data exchanges & Auditing IEC61850 automated substation. Auditing uses security matrices that quantify the security of the network. Then intrusion detection system must be deployed as a countermeasure [76] \\ \hline
[74,75] & Fault injection attack (FIA) and false data injection on IED through invasive and noninvasive methods & Auditing IEC61850 automated substation. Auditing uses security matrices that quantify the security of the network. Then intrusion detection system must be deployed as a countermeasure [76] \\ \hline
[77] & GOOSE Poisoning (high-status number attack, high-rate flooding, and semantic attack) due to predictable status number employed in GOOSE messages and processing numbers from the subscriber preventing legitimate COOSE messages & The employment of SDN provides a secure rule for incoming GOOSE messages. Moreover, it can restrict the flow of messages for a single output port to mitigate the unnecessary spread of GOOSE messages [66]. \\ \hline
[87] & Cyber intrusion attacks on IEC61850 modify GOOSE and SV messages and trip substation breakers & The use of a software-defined network (SDN) switch eliminates possible paths of intrusion and network data overload [66]. \\ \hline \end{tabular}
\end{table}
Table 3: Security concerns and mitigating measures of IEC 61850.