Towards a middleware architecture for deterministic reconfiguration of service-based networked applications

The increasing complexity of networked embedded systems (NES) brings in the vision of large-scale systems made of subparts with decoupled interaction. In highly decoupled environments, it is required to introduce software paradigms that adjust well to this degree of independence among subsystems. In modern NES, real-time properties and reconfiguration facilities are not only an added value but an unavoidable trend that research is currently focusing at. Service-oriented architectures (SOA) are an easy-to-understand natural means to provide such decoupled model of operation; service-based applications are made of a set of self-contained pieces of functionality (services) that cooperate by exchanging messages to provide the application's common goal. This paper presents a middleware architecture that includes real-time support for service-oriented NES. The architecture includes the fundamental set of functions to support timely service-based composition and execution. The architecture is the core part of the iLAND project that aims at supporting deterministic service-based composition and reconfiguration in service-based NES. The architecture can be built on top standard communication middleware cores (as DDS or RT-CORBA), since it supports synchronous and asynchronous communication models. An experimental set up for real-time video transmission has been developed to validate it.