A flexible optical switch architecture for efficient transmission of optical bursts

Abstract

In this paper, we propose a new optical switch architecture for optical WDM networks. Flexibility and efficiency in terms of controlling and utilizing optical power are key features of the architecture. The architecture uses switching components which have increased flexibility of how optical power received on an input port is managed when switching optical signals. Like the traditional optical switches, optical power can be directed towards one output port only. Further, unlike the traditional switches, on need basis, the power can be split on a desired sub-set of output ports, thus reducing power wastage on unwanted ports. Such split power can be directed fully towards a single output port as and when it is needed. This flexible and efficient power management makes the architecture a potential candidate for optical networks with its usage in several dimensions. The dimensions include (1) switching methods such as circuit level switching and bursty level switching, (2) network types such as core, metro, and access networks, (3) support for technologies such as Light-trails and Light-trees, and (4) support for functionalities such as survivability and multicasting with new features. Importantly, there is potential that the architecture enhances adaptability based on the needs, and it supports co-existence and seamless integration of different environments. In this paper, our focus is on investigating bursty level switching using the proposed switch architecture. We use the flexibility of the switch and adopt a new switching method for data bursts. This switching method is efficient for switching bursts while introducing new challenges. Unlike the traditional switching method, it switches bursts arriving on an input link with zero (or very small) time gaps to different output links in certain scenarios. Further, it also switches bursts from different input links to the same output link when they arrive with zero (or very small) time interval. Adopting such switching approaches has potential benefits in terms of delay-load performance and blocking performance. While the bursts are switched from the same input link to different output links in this approach, it creates some unwanted signals. We investigate scenarios in which the unwanted signals create any problems and this poses some challenges. To address such challenges, we develop a transmission protocol. We investigate the performance of our solutions using simulation studies and verify the two significant gains: (1) networks' capability to sustain traffic loads up to the maximum level in terms of the delay-load performance, which is similar to the performance seen for hypothetical ideal switches with zero switching time, and (2) improved blocking performance. © 2012 Elsevier B.V. All rights reserved.