AWG-based Nonblocking Shuffle-Exchange Networks

The optical Shuffle-Exchange Networks(SENs)have widespread applications in massive-capacity,large-scale,high-speed switching and interconnections.However,the existing design methods of optical SEN have their defects in terms of practicability.For instance,the Free Space Optics(FSO)-based schemes feature bulky,costly,and is difficult to adjust and maintain;the fiber-based SENs have large cabling complexity;the existing arrayed waveguide grating(AWG)-based scheme is not scalable,and does not make full use of the optical components.We plan to construct a scalable AWG-based SEN.The construction of optical shuffle network is the key step to construct the optical SEN.Therefore,we firstly design the modular AWG-based shuffle network.We define the structure of general shuffle networks,and introduce two main properties of shuffle networks.With the wavelength routing property of AWGs,we show for the first time that an AWG is functionally equivalent to a classical shuffle network by nature.However,the single-AWG based shuffle network is not scalable due to its physical performance.Therefore,we consider the construction of modular AWGbase shuffle network using a set of small scale AWGs with the help of modulo operation on the routing table.Besides,we demonstrate the general structure of the modular AWG-based shuffle networks,and give some advice on the parameters configuration of the networks.Secondly,we combine the modular AWG-based shuffle networks and the TWC-modules,and obtain an AWG-based WDM SEN.We dig into the RWA of this WDM network and shows that the self-routing property is preserved in this network.Derived from the nonblocking conditions of the classic SENs and the WDM networks,we prove that the routing of many connection requests in the AWG-based SENs are nonblocking if their inputs and outputs follow meet certain requirements.Our proposed AWG-based WDM SEN is highly scalable because the scale of AWGs,the conversion range of TWC-modules and the wavelength granularity are relatively small,and signal impairments do not accumulate from stage to stage.Also,the utilization of the optical devices is 100% if all the wavelength channels of the networks are busy.