Multiprocessor interconnection networks using partitioned optical passive star (POPS) topologies and distributed control

The authors present a scalable electro-optical interconnection network architecture which is suitable for tightly coupled multiprocessors. The architecture is called a partitioned optical passive star (POPS). It is a type of multiple passive star topology in which only constant and symmetric coupler fanouts are used and in which exactly one coupler is traversed on any path through the network. Control is based on the state sequence routing paradigm which multiplexes the network between a small set of control states and defines a control operation to be a transformation of those states. These networks have highly scalable characteristics for optical power budget, resource count, and message latency. Optical power is uniformly distributed and the size of the system is not hard limited by the power budget. Resource complexity grows with asymptotic complexity O(n) for the couplers, O(n√n) for transceivers, and O(√n log(n)) for control. We present a static analysis and a simulation of dynamic performance which demonstrates the ability of a POPS design to support 1024 nodes using current device and coupler technology