# Secure and Time-Aware Communication of Wireless Sensors Monitoring Overhead Transmission Lines
## 4 Transmission Grid Model in Quality of Protection Modeling Language  
### QoP-ML Overview  
In the article [17] the QoP-ML was introduced. Proposed solution provides the modeling language for making abstraction of cryptographic protocols that puts emphasis on the details concerning the quality of protection. The intended use of QoP-ML is to represent the series of steps, which are described as a cryptographic protocol. The QoP-ML introduced the multilevel protocol analysis that extends the possibility of defining the state of the cryptographic protocol. Since approaches presented in the literature usually speak for an example of a model driven security, in the light of the available development methodologies, QoP-ML excellently fits in a design known as a Model-Driven Engineering. The Model-Driven Engineering (simply known as MDE) is meant to focus on the creation and utilization of the abstract representations of the knowledge that govern a particular domain, rather than on the computing, algorithmic or implementation concepts. Model-Driven Engineering  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Scenario**} & \multicolumn{2}{c}{**Number of Direct**} & \multicolumn{2}{c}{**Number of**} \\  & **Links to Substation (\(c\))** & **Hops (\(\eta\))** & **Routing Type** & **Security Mechanisms** \\ \hline \(1(a)\) & 2 & 22–23 & hop by hop & No Encryption \\ \(1(b)\) & 2 & 22–23 & hop by hop & Encryption (AES-CTR, 128) \\ \hline \(2(a)\) & 45 & 1 & direct link & No Encryption \\ \(2(b)\) & 45 & 1 & direct link & Encryption (AES-CTR, 128) \\ \hline \(3(a)\) & 12 & 2 & central point & No Encryption \\ \(3(b)\) & 12 & 2 & central point & Encryption (AES-CTR, 128) \\ \hline \(4(a)\) & 8 & 3 & central point & No Encryption \\ \(4(b)\) & 8 & 3 & central point & Encryption (AES-CTR, 128) \\ \hline \(5(a)\) & 1 & 45 & central point & No Encryption \\ \(5(b)\) & 1 & 45 & central point & Encryption (AES-CTR, 128) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Scenarios prepared for our case study.  
Figure 7: WSN architecture deployed on the example transmission grid, where \(\eta=3\).  
approach is a broader concept than Model-Driven Architecture (MDA), or Model-Driven Security (MDS). MDE adds multiple modeling dimensions and the notion of a software engineering process. The various dimensions and their intersections together with a Domain-Specific Language (DSL) form a powerful framework capable of describing engineering and maintenance processes by defining the order in which models should be produced and how they are transformed into each other. Serving as a domain-specific language, QoP-ML is capable of expressing security models in a formalized, consistent and logical manner.  
As is apparent from the above description, QoP-ML is a flexible, powerful approach to model complex IT environments. Therefore, we utilized it to prepare our case study and evaluate the quality of chosen security mechanisms using its supporting, automatic framework. In the following sections we present all the significant components of the language we utilized to create model for our scenario.