# Secure and Time-Aware Communication of Wireless Sensors Monitoring Overhead Transmission Lines
## 1 Introduction
Since monitoring and control of electric power systems are essential for their efficient and effective functioning, WSNs, as a low-cost, flexible and self-organizing devices, appear to be the perfect choice for creating a highly reliable and self-healing smart power grid that rapidly responds to online events with appropriate actions. The nature of WSNs brings significant advantages over traditional communication technologies. WSNs are characterized by a rapid and straightforward deployment (even in difficult-to-access and large geographical locations), high coverage area, low installation and maintenance costs, as well as easy replacement and upgrading procedures. Furthermore, they have the capability to organize and configure themselves into effective communication networks. Their flexibility and mobility is higher than the one of the wired networks. Potential applications of WSNs on smart grid span a wide range, including, but not limited to: power quality monitoring, outage detection, overhead transmission line monitoring (such as conductor elongation or temperature measurements in dynamic load rating systems), fault detection and location, equipment fault diagnostics and underground cable system monitoring [5]. The collaborative and context-aware nature of WSN brings several advantages over traditional sensing including greater fault tolerance, improved accuracy, larger coverage area, and extraction of localized features. Despite undeniable advantages, there are also several challenges, such as security. As is the case with all kinds of wireless networks, WSNs are more vulnerable to security threats originating from the open communication environment, which pose serious risks and expose the system to many threats. Unlike other wireless technologies, applying advanced and complex security mechanisms to WSN is not applicable due to their physical limitations. This complicates protection measures and makes WSNs more vulnerable to external attacks. Moreover, WSN-based smart grids suffer from all the security threats facing classical WSN communication. Because of their complexity, large number of stakeholders, and highly time-sensitive operational requirements, power grids have additional vulnerabilities and are prone to varied types of attacks [6; 7; 8]. One should also remember, that available security solutions, even those designed for WSNs, are also very often costly and consume large amounts of the Central Processing Unit (CPU). Another drawback of using WSNs on long distances, are time delays. The delays in information transmission depend, among others, on the possibility of practical use of the structure of WSN to/for the DLR or to support the work of securing or blocking its action. Remaining delays are related to utilized routing algorithms and depend on how far the data needs to travel through the transmission grid and the time when the collected data is finally sent to the base station. For environments with rigorously defined requirements on data delivery, it is essential to minimize the information transmission delay in order to allow for efficient and effective communication. Hence, in this paper, we focus on minimizing delay time considering the reliability of the communication simultaneously. To overcome the above issues, we proposed the secure and reliable communication plan for WSN in transmission grid systems. In this paper, we contribute to analyzing and solving the problem of time delays generated during measurement data transmission. The main contributions of this paper are summarized as follows. * In order to find a trade-off between the security, performance and time delays, we design a reconfigurable network model and demonstrate a feasible analysis considering various practical issues, concerning routing operation of the WSN and the security of the data traversing transmission grid.