Design And Simulated Implementation Of Fault-tolerant Mechanisms In 3D Optical Network-on-chip

With the rapid development of multi-core technology on a chip,the Optical Network-on-Chip(ONoC),especially the 3 Dimensional ONoC(3D ONoC)has attained extensive attentions as a new NoC architecture.Compared with the traditional NoC based on electric interconnections,the 3D ONoC can provide higher communication bandwidth,as well as lower transmission delay and power consumption.However,the requirement of craftsmanship and working environment of the novel and high-efficient 3D ONoCs is very strict because the incomplete craftsmanship and potential crosstalk will make some function become disabled,leading to the faults in 3D ONoCs.Neglecting the fault tolerance in the current works makes the network impossible to use,thus resulting in an irreversible loss.Therefore,this thesis will design fault tolerant mechanisms for three kinds of possible 3D ONoC failures,in order to improve the network reliability.In 3D ONoCs,the data transmission and switching are mainly performed through microring and optical waveguide.Thus,considering the 3D ONoC as the research object,this thesis designs the fault-tolerant mechanisms for the disabled cases of mircoring and optical waveguide,respectively.First,this thesis constructs the 3D Torus topology structure so as to reduce the transmission distance between any pair of Optical Router(OR)nodes.Moreover,according to the characteristic of 3D Torus topology and component failures,the novel OR structure,the Fault-Tolerant Routing Algorithm based on fault Node Reuse(FTRA-NR),and the Fault-Tolerant Routing Algorithm based on Bidirectional waveguide Link(FTRA-BL)are proposed by us.When an OR node becomes disabled,the aforementioned fault-tolerant mechanisms degrade the failure granularity into the internal OR structure,where the backup microcosmic path within the disabled OR can be established along normal microring and optical waveguides.As a result,even with the OR failure,the disabled OR still can be utilized as the intermediate node of the macroscopic path without detouring around the entire faulty OR or optical waveguide,thus leading to the improvement of resource utilization while guaranteeing the optimal macroscopic path well maintaining the network performance.Finally,this thesis conducts simulations and analyzes the performance of the proposed OR structure and two fault-tolerant mechanisms.The simulation results demonstrate that our method performs well in terms of transmission delay,power loss,crosstalk noise,signal-to-noise ratio and bit error rate.Above all,this thesis work has a certain reference value for improving the reliability and fault tolerance of 3D ONoCs.