Swarm-Intelligence-Based Routing and Wavelength Assignment in Optical Satellite Networks

Routing and wavelength assignment (RWA) determine the quality of service (QoS) such as blocking probability and delay in wavelength division multiplexing (WDM) satellite optical network, whose topology is time-varying due to the high-speed mobility between satellite orbits. This article introduces an ant colony optimization with adaptive load balance small window strategy under hop number loose constraint (ACO-ALB-SWS-HNLC) which has highly robust to solving the RWA issue in the dynamic topology of the satellite optical network. In our proposed algorithm, an adaptive small window strategy and hop number loose constraint are proposed to improve the convergence speed and reduce the number of node hops by limiting its convergence area adaptively through the load in the window. The pheromone evaporation rate is controlled by wavelength usage between the links in the window to balance the load. The result shows that, compared to other ACO algorithms, ACO-ALB-SWS-HNLC can effectively reduce blocking probability. In addition, good convergence speed and communication delay are maintained as well.

I. Introduction

With the explosive growth demand of video service, instant message applications, and the rapid development of the Internet of Things [1], [2], [3]. Future networks are excepted to provide more communication and computing resources to cope with the growing demand for services [4]. In the era of the Internet of everything, not only do people need communication, the exchange of information between people and things is the same important. In addition, the remote mountainous areas and the ocean are also in need of communication [5]. Traditional terrestrial networks are limited by capacity and coverage capability and cannot meet the demand for high-speed data transmission and highly reliable access services for existing IoT architectures [6]. The IoT related issues have aroused a wide range of research interests of scholars [7], [8].