Risk-Avoid Lightpath Provision in Space Division Multiplexing Elastic Optical Data Center Networks

This paper aims to tackle the issue of risk-avoid lightpath provision in multi-domain space division multiplexing (SDM) elastic optical data center networks (SDM-EODCNs). The service requests are categorized as intra-domain or inter-domain, and inter-domain requests are further classified as trusted or untrusted. A system model is presented, including a network model, a service request model, an inter-core crosstalk (IC-XT) model, and a risk model between service requests. To reduce the blocking probability of service requests while avoiding security risk, an integer linear programming (ILP) model is formulated to minimize the maximum index of frequency slots occupied by all types of service requests. Furthermore, a risk-avoid lightpath provision algorithm (RALPA) is proposed, consisting of different algorithms like data center selection, core prioritization, frequency block determination, and core and frequency slot allocation. RALPA ensures that trusted service requests remain secure from potential attacks by untrusted ones. Additionally, core priorities are dynamically generated for different service requests, reducing the search space and improving the search's time efficiency. Finally, the ILP model is solved in small-scale topology, and large-scale simulation experiments are conducted on various network topologies and core structures. The results show that our RALPA algorithm outperforms the benchmark algorithms in terms of blocking probability and utilization of network resources.

I. Introduction

Optical networks that utilize wavelength division multiplexing (WDM) technology often waste spectral resources due to their coarse-grained channel provision capabilities [1]. Elastic optical networks (EONs) [2] that use advanced m-ary quadrature amplitude modulations (M-QAM) and bandwidth variable transponders (BVT) technologies have been introduced to provide finer network connections. Additionally, space division multiplexing (SDM) [3], [4], [5] technology based on multi-core fibers (MCFs) [6], [7] has been developed to further enhance the transmission capacity of EONs from the space dimension. With the rapid advancement of cloud computing technology [8], [9], computing resources in data centers are now highly virtualized. This has led to the emergence of SDM elastic optical data center networks (SDM-EODCNs), which accelerate the integration of computing and optical networks [10], [11]. This integration provides a solid foundation for the digital transformation of various aspects of life.