Wavelength converter allocation and ranging for multi-fiber share-per-link switches in slotted/unslotted all-optical networks

Abstract

The end-to-end performance for circuit switched all-optical networks in multi-fiber multi-hop environments is modeled and evaluated with and without wavelength conversion. The increase in performance in wavelength routing DWDM network due to wavelength conversion at each node with different degrees of wavelength conversion is considered. Models relating parameters such as hop count, number of fibers, number of wavelengths in each fiber, and degree of conversion to end-to-end performance are developed. This work also examines different wavelength converter sharing architectures and their effects on performance when the hops along the path between source-distention pair have different loads. It also examines the performance issues for share-per-link wavelength convertible switch (WCS) using different Conversion Resources Allocation Algorithms (CRAA). We propose and evaluate three different CRAA algorithms, Narrow Search Algorithm (NSA), Inclusive Search Algorithm (ISA), and Optimized Inclusive Search Algorithm (OISA), for dynamically allocating conversion resources. As a second major topic of this research, the effects of different wavelength conversion ranging configurations on the performance of Wavelength Division Multiplexing (WDM) optical switches are investigated. Any-to-Any, Any-to-Range, Range-to-Any, and Range-to-Range conversion ranging configurations are considered. These mechanisms provide important design alternatives for optical switches due to technological limitations in the implementation of full range wavelength conversion in an all-optical wavelength converter device. Limited-range wavelength converter (LRWC) is a more economical and practical solution for WDM based optical networks. Differences among the input and output side ranging mechanisms and their effects on conversion resource sharing, and consequently on performance, are investigated. Any-to-Range ranging configuration is the most efficient mechanism and it operates comparably to Any-to-Any. The obtained results help in determining the most efficient ranging configuration for all-optical crossconnect. Finally, we study the synchronous optical packet-switched (OPS) networks with limited number of converters that are shared between all wavelengths on specific output link (Share-per-Link WCS). The end-to-end performance of such networks, which service symmetric/asymmetric traffics at each node along the path between the source and destination, is modeled. The effects of employing multiple fibers on the network performance and how that affects the needed conversion resources are studied in detail. The multi-fiber synchronous photonic share-per-link packet switch model is used as the basic switch element on which the linear end-to-end network model is built. Different performance aspects and tradeoffs, which are used to grasp the quantitative performance differences when using multiple fibers and the adaptation of limited wavelength conversion, are investigated.