Abstract: Active network was developed to solve the problem of
the current sharing-based network–difficulty in applying new
technology, service or standard, and duplicated operation at several
protocol layers. Active network can transport the packet loaded with
the executable codes, which enables to change the state of the network
node. However, if the network node is placed in the sharing-based
network, security and safety issues should be resolved. To satisfy this
requirement, various security aspects are required such as
authentication, authorization, confidentiality and integrity. Among
these security components, the core factor is the encryption key. As a
result, this study is designed to propose the scheme that manages the
encryption key, which is used to provide security of the
comprehensive active directory, based on the domain.
Abstract: Time varying network induced delays in networked
control systems (NCS) are known for degrading control system-s
quality of performance (QoP) and causing stability problems. In
literature, a control method employing modeling of communication
delays as probability distribution, proves to be a better method. This
paper focuses on modeling of network induced delays as probability
distribution.
CAN and MIL-STD-1553B are extensively used to carry periodic
control and monitoring data in networked control systems.
In literature, methods to estimate only the worst-case delays for
these networks are available. In this paper probabilistic network
delay model for CAN and MIL-STD-1553B networks are given.
A systematic method to estimate values to model parameters from
network parameters is given. A method to predict network delay in
next cycle based on the present network delay is presented. Effect of
active network redundancy and redundancy at node level on network
delay and system response-time is also analyzed.