Research On High Speed Algorithm For Crossbar Switch

Along with the development of digital information, there comes up with abundant and various applications, which require a lot on throughput, QOS, and real time process, so as bottleneck of communication, switch structure become the key point of research. Problems of structure of switch is researched. then pay more attention to switch structure based on crossbar and put forward a algorithm based on thresh hold.Present structure and algorithm of switch focus on matching efficiency, QOS, stability, and complexity of implementation. Combined input and cross point queue have advantage due to relative independency. it can be more parallel due to its independent and distributed memory.Based on analysis of the nature of CICQ(CICQ: Combined Input and Crossbar Queued switch) model, propose a new conception-instant speedup and effective speedup, then point out that instant speedup is a resource in CICQ model. Also analyse the affection of input queue and output queue on performance of system, realize that instant speedup should be assigned to output queue which will be empty. Based on this analysis, propose an input arbitration algorithm-TCBF(Thresh-hold Cross point Buffer First),present proof of its stability, get simulation result on this model, including affection of cross point buffer size and speedup on performance, and performance of different thresh hold of TCBF, then make two kinds of improvement for nonuniform pattern-time slice and double address pointer. Simulation result shows that this algorithm with O(1) complexity can have high though put, don't need big cross point buffer and high speedup, have best performance at thresh hold 0, have similar performance with OQ-N, and it's also very easy to implement.