Software cybernetics to manage adaptation behavior of complex network systems

Abstract

We employ model-based software (MBS) techniques to assess the quality of adaptation in a network system S in the presence of uncontrollable external environment conditions. The lack of complete knowledge about the I/O behavior of S arises due to large dimensionality of the input parameter space and their interactions with the various components in S. The MBS techniques adapt the operations of S over multiple “observe-adapt” rounds and steer S towards a reference input specs. How close is the actual behavior to the reference input depicts the quality of adaptation by S. The paper provides a cyber-physical systems (CPS) based software structure to evaluate the non-functional attributes of the output behavior of S, and autonomically adjust the network and algorithm parameters therein for effective control of S. The paper corroborates our CPS-based approach with a case study of QoE-aware video rate adaptation over a bandwidth-limited network path.