## 5 A Case Study on Reliable Pipeline Monitoring Using Cyber Physical Sensor Networks
### Architecture for Remote Pipeline Monitoring
Hence, no specific predefined network topology exists and a random deployment is followed across the length of the pipeline. Also, in the oil industry, the position of the wireless nodes is not changed very often. Hence, sensing nodes are deployed only once and replaced from their locations only if they malfunction or get critically damaged. Integrated sensors such as fluid level indicators, pressure, temperature and fire detection sensors are deployed according to specific industry requirements for certain places (Table 5). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sensor Used**} & \multirow{2}{*}{\begin{tabular}{c} **Fluid Inside** \\ **Pipeline** \\ \end{tabular} } & \multirow{2}{*}{**Sensor Placement**} & \multirow{2}{*}{**Events Detected by Sensor**} & \multirow{2}{*}{\begin{tabular}{c} **Physical** \\ **Phenomenon** \\ \end{tabular} } \\ \hline Acoustic & \multirow{2}{*}{Any} & \multirow{2}{*}{Outside the pipe} & \multirow{2}{*}{High frequency noise} & \multirow{2}{*}{Leakage} \\ sensor [29] & & & & \\ \hline Acoustic & \multirow{2}{*}{Any} & \multirow{2}{*}{Outside the pipeline} & \multirow{2}{*}{High frequency noise} & \multirow{2}{*}{\begin{tabular}{c} Presence of solid \\ particles in the fluids \\ \end{tabular} } \\ sensors [29] & & & & \\ sensors [29] & & & & \\ \hline pH sensor [30] & \multirow{2}{*}{Water} & Inside the pipeline-in & \multirow{2}{*}{pH variation} & \multirow{2}{*}{Contamination} \\  & & contact with the fluid & & \\ \hline Optical Fiber & \multirow{2}{*}{\begin{tabular}{c} Gas \\ sensor [38] \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} Above the pipeline \\ Gas \\ \end{tabular} } & \multirow{2}{*}{All Major} & \multirow{2}{*}{Leakage} \\  & & & & \\ \hline Optical Fiber & Liquid & \multirow{2}{*}{\
\begin{tabular}{c} Beneath the pipeline \\ (Water/Oil) \\ \end{tabular} } & \multirow{2}{*}{All Major} & \multirow{2}{*}{Leakage} \\ sensor [38] & & & & \\ \hline Hydrocarbon & \multirow{2}{*}{Oil} & \multirow{2}{*}{Outside the pipeline for underground pipelines} & \multirow{2}{*}{Change in the concentration of hydrocarbon vapor} & \multirow{2}{*}{Leakage} \\ vapour sensor & & & & \\ \hline Magnetostrictive & \multirow{2}{*}{Any} & \multirow{2}{*}{Inside the pipe} & \multirow{2}{*}{
\begin{tabular}{c} Strain upon the \\ piezo-electric sensors \\ \end{tabular} } & \multirow{2}{*}{Rust/Blockage} \\ Sensor MsS [44] & & & & \\ \hline Pressure & \multirow{2}{*}{Any} & \multirow{2}{*}{In contact with fluid} & \multirow{2}{*}{Fluid Pressure} & \multirow{2}{*}{Leakage} \\ Sensors [66] & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Sensor devices used in industry for event detection. Oil and gas pipeline monitoring systems do not use wireless sensing nodes in bulk; instead, selected nodes are installed on predefined locations. Fluid level indicators, pressure and temperature based wireless sensor nodes are deployed in production plants that are usually fixed. In the oil industry, node mobility is not required because sensing nodes are placed at a fixed location for calibration of various real-time changes in the condition and state of the product. In pipeline monitoring systems, the sensor plane is designed in such a way that each node directly communicates to the base station. For industrial environments, wireless sensor gateways are installed which take care of transporting the data to the base station. Every wireless sensor gateway is responsible for collecting data from its specified units. From surveys, it is concluded that it is preferable that sensor gateways are installed in an operation room. The distances between the wireless sensor gateways and the sensor nodes are kept at around 100 m. The deployment would also depend on the specific part being monitored in the complete fluid delivery system.