Performance assessment of data and time-sensitive wireless distributed networked-control-systems in presence of information security

Distributed network-control-systems (D-NCS) are a network structure and components that are capable of integrating sensors, actuators, communication, and control algorithms to suit real-time applications. They have been gaining popularity due to their high potential in widespread applications and becoming realizable due to the rapid advancements in embedded systems, wireless communication and data transfer technologies. This paper addresses the issue of D-NCS information security as well its time-sensitive performance with respect to network security schemes. We use a wireless network based, robot navigation path tracking system called Intelligent Space (iSpace) as a D-NCS test bed in this paper. The paper classifies the delay data from every NCS module (sensors, actuators and controllers). We define performance parameters for this NCS test bed. Various system factors including network delay, system gain, affecting these performance parameters are recognized. Network security algorithms DES and 3DES are integrated with the application to secure the sensitive information flow. Standard statistical approach such as 2(k) factorial experiment design, analysis of variance, hypothesis testing is used to study and estimate the effect of each factor on the system performance especially security features. Thorough experimental results, tables of detailed characterization and effect estimate analysis is presented followed by the discussion on the performance comparison of NCS with and without wireless security.