Fibre-Optic AWG-based Real-Time Networks

Abstract – This paper is a summary of our recent research on real-time solutions for WDM networks. We present two multiwavelength passive optical networks based upon a single-hop star topology with an Arrayed Waveguide Grating (AWG) at its centre and propose two corresponding Medium Access Control (MAC) protocols based upon Earliest Deadline First (EDF) scheduling. Traffic scheduling is centralized in one node (residing together with the AWG in a hub), which communicates through a physical control channel. The AWG’s property of spatial wavelength reuse and the combination of fixed tuned and tuneable transceivers in the nodes enable simultaneous control and data transmission. This makes it possible to meet the main goal, i.e. guaranteeing support for hard and soft real-time traffic. The chosen application areas for the two networks are short range communication systems like System Area Networks (SANs) for use in embedded systems and a router architecture with electronic queuing. A case study in the field of Radar Signal Processing (RSP) and a simulation were conducted for the two application areas respectively, showing good results in both areas