## 4 Development of NCS from 2011 Onwards
In Reference [147], the problem of event-triggered finite-time control for networked switched control systems with extended dissipative performance was investigated. In Reference [148], the authors proposed a scheduling approach which can minimize the impact of delays and conflicts on the network, to improve the system stability, which results in an economical allocation of network resources, minimizes the traffic congestion, and improves the overall performance of the NCS. In Reference [149], the authors discussed about the effect of limited bandwidth on the system's performance, particularly when the sampling period was small. In Reference [150], the authors discussed the amalgamation of control and communication in NCSs that offers remarkable achievement in the design and analysis of such controlled systems. In Reference [151], the authors discussed the LMI approach to effectively compensate for the random network-induced delays and provide the desired control performance. In Reference [152], a new ETM was proposed, under which data packets could be actively dropped within consecutive steps, thereby, saving more communication resources than the existing ETM. In Reference [153], the authors proposed the descriptive analysis about classification of cyber-attacks and threats related to security in industrial control systems. In Reference [154], the authors proposed a new quantization structure, and a mathematical treatment of this structure was given to illustrate the advantage for the quantization effects. The above developments can be summarized in tabular form in Table 4 on the basis of area/network/parameter as follows. \begin{table}
\begin{tabular}{c c c} \hline \hline
**S.No.** & **Papers** & **Parameter/Area/Network** \\ \hline \multirow{2}{*}{1} & [86,89–91–103,107,112,113, 119,122,128,131,136] & \multirow{2}{*}{Model/Sampling Based Networks} \\  & 119,122,128,131,136] & \\ \hline \multirow{2}{*}{2} & [85,88,90–92,97,98,100,101,107, 114,117,132,144] & \multirow{2}{*}{Stability Analysis/Approach} \\  & 114,117,132,144] & \\ \hline \multirow{3}{*}{3} & [86,87,91,93,98,100,101,106– 108,112,113,115– 125,129,130,132–134,137– 142,144–146,149,151] & \\  & 125,126,137,140,145] & \\ \hline \multirow{3}{*}{4} & [92,93,99,107,109,110,114,121, 125,126,137,140,145] & \multirow{3}{*}{Distributed Networked Control Approach} \\  & 135,142] & \\ \hline \multirow{3}{*}{6} & [96,97,103,107,126,127,129,135, 138,139,143,147,152,154] & \\  & 138,139,143,147,152,154] & \\ \hline \multirow{3}{*}{7} & [98,107] & \multirow{3}{*}{Interactive Networks} \\  & \multicolumn{1}{c}{} & \\ \cline{1-1} \cline{5-5}  & \multicolumn{1}{c}{} & \\ \end{tabular}
\end{table} 
Table 4: Summarized discussion of development of NCS from 2011 onwards. Table 4 gives the structured information on the distribution of papers in different areas published from the year 2011 onwards. The major focus of research during this phase was on the delay-based networks. The difference between the works published in the earlier phases is that the security approach, model-based approach, and the sampled-based approach involve the incorporation of delays. Secondly, the advanced model-based networked approaches, such as Model-Predictive Control (MPC), OFOFC networks, etc., were proposed, which make the networked system more stable and improve its performance. Figure 5 shows the distribution of papers during this phase. It can be clearly noticed that major focus is on the delay-based approach, which covers approximately 37% of the research contribution. The stability approach is also very important as the stability depends on delay. If the delay is maximum, the system has to be designed to make it stable. To achieve this purpose, many event-based techniques were developed.