Cyber-Physical Systems Based Modeling of Adaptation Intelligence in Network Systems

The paper uses the cyber-physical systems (CPS) framework to model the intelligent adaptation behaviors in complex network systems. The CPS framework is anchored on intelligent physical worlds (IPW) around which complex adaptation behaviors are built. An IPW is an embodiment of control software functions wrapped around the raw physical processes (such as routers, links, hosts, and protocols), performing the core communication activities while adapting its behavior to the changing network conditions and user inputs. The IPW exhibits an intelligent behavior over a limited operating region of the network system, which is in contrast with the traditional models where the physical world is basically dumb. To perform over a wider range of network operating conditions, the IPW interacts with an intelligent computational world (ICW) to patch itself with suitable control parameters and rules & procedures relevant in those changed conditions. The modular decomposition of a network application into IPW and ICW lowers the design complexity of network systems, and simplifies the system verification/testing. The paper illuminates our CPS-based approach with a case study of adaptive video transport over a bandwidth-limited network.