Abstract
Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.
1. Introduction
Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth [1-2]. An optical packet network consists of optical packet switches interconnected with fibers running WDM. The switches may be adjacent or connected by lightpaths. A lightpath is a circuit-switched connection consisting of the same wavelength allocated on each link along the path. It may consist of different wavelengths along the path if converters are present. The user data is transmitted in optical packets, which are switched within each optical packet switch entirely in the optical domain. Thus, the user data remains as an optical signal in the entire path from source to destination. No optical-to-electrical or electrical-to-optical conversions are required.
5. Conclusions
In this study we have surveyed most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. We found that the output buffered architectures give better performance than input buffered architectures. Another comparison based on the components involved in various architectures is also presented. The-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.
