Information security with real-time operation: performance assessment for next generation wireless distributed networked-control-systems

Distributed network-control-systems (D-NCS) are a multidisciplinary effort whose aim is to produce a network structure and components that are capable of integrating sensors, actuators, communication, and control algorithms in a manner to suit real-time applications. They have been gaining popularity due to their high potential in widespread applications and becoming more realizable due to the rapid advancements in wireless communication and data transfer technologies. This paper addresses the issue of D-NCS information security as well its real-time performance with respect to network security protocols and encryption 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 data from every NCS module (sensors, actuators and controllers) according to bandwidth requirement, time and information sensitivity. We define performance parameters for this NCS test bed. Various system factors affecting these performance parameters are recognized. Network security algorithms DES and 3DES are integrated with the application to encrypt the sensitive information flow. These wireless security features are considered as an added factor to the NCS. Standard statistical approach (2^k factorial experiment design) is used to study and estimate the effect of each factor on the system performance especially security additions. 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.