## 3 Development of NCS between 2001 to 2010  
During this period, the key concepts of NCS, which were proposed earlier, received more attention, and the volume of research increased tremendously. One of the main themes of this period was the controller design for NCS with stability analysis and time delay. An important work on scheduling method for NCS was proposed by [PERSON] [32]. This method guaranteed the stability using Lyapunov method. Next, a work on the impact of modern networked architecture on control act of NCS was published by [PERSON] [33]. In Reference [34], the procedures for selecting the message recognizers for vigorously scheduled networked systems were proposed and validated. In Reference [35], recital benefits were established by dispensing with queues and by vigorous traffic scheduling on the network. An uncomplicated and easy model of a network system was proposed in Reference [36], in which local controllers connected by a network was addressed. In Reference [37], it was discussed that any complex self-motivated communications network typically has several layers and executive units and would be at risk of several disturbances. Therefore, the requirement for efficient and intelligent control of the systems must be used [38]. In Reference [39], an original networked control protocol, called try once-discard, has been proposed for multiple-input and multiple-output (MIMO) NCSs. A style technique of memoryless-quantizers in sampled-data models was planned by [PERSON] [40]. The objective was quadratic stability within the continuous time (CT) domain. In Reference [41] a general framework for the NCSs was given, where all elements were assumed to be connected through a communication network. They used the uncertainty threshold principle to point out that, with the bound conditions, even in an undisturbed NCS there would be data rates that degrade the performance of networked control due to the network induced delays and can lead the system to the instability [42]. In Reference [43], web-based multi-rate control systems were presented. It was suggested that the effect of web time delay on the control performance can be reduced by using the time delay compensation. A novel networked control strategy developed by [PERSON] [44], analyzes the soundness of the networked systems with unsystematic delay in the communication. It consisted of a network control predictor and a traditional controller. The soundness criteria of a networked system were analytically derived for random  
Figure 3: Distribution of focus areas of NCS research prior to 2000.  
communication delays. In Reference [45] a state observer for the networked systems with a delay in the time period was designed. Authors claimed that the state observer supported the satisfactory performance of the NCS, even with delay in the time period. Another review paper [46], which appeared within the same year, was centered on network-induced delays, sampling amount, jitter, information packet dropout, network programming, and stability of Ss. In Reference [47], authors studied the result of a network within the feedback circuit of an NCS. A random packet-loss model for the network was considered. A classical work on the design of robust H-infinity (Hoo) controllers for NCSs with uncertainties was given by Reference [48] that additionally considered the network-induced delay and information dropout. Next, the delays due to the sensor-to-controller and to-actuator were sculptured as two Markov /stochastic chains in Reference [49]. Input/output delay approach was considered by Reference [50] to style the strong sampled-data strong control. Enough LMI conditions were obtained by Lyapunov-Krasovskii functionals. In Reference [51], the straight line stability and straight line persistent disturbance attenuation problems were investigated for NCSs under the effects of random access delays and packet dropout. A robust controller was designed in Reference [52] for the NCSs with random time-delays, using the linear matrix inequality (LMI).