Róża Goścień

Wrocław University of Science and Technology | WUT · Department of Systems and Computer Networks

We focus on the efficient modeling and optimization of the flow restoration in the spectrally-spatially flexible optical networks (SS-FONs) realized using a single mode fiber bundle. To this end, we study a two-phase optimization problem, which consists of: (i) the network planning with respect to the spectrum usage and (ii) the flow restoration af...

The paper studies efficient modeling and prediction of daily traffic patterns in transport telecommunication networks. The investigation is carried out using two historical datasets, namely WASK and SIX, which collect flows from edge nodes of two networks of different size. WASK is a novel dataset introduced and analyzed for the first time in this...

The rising popularity of the telecommunication networks and their growing support in our every-day life make them a potential target of various security threats and malicious attacks. The international security organisations warn against increasing likelihood of nuclear weapon or electro-magnetic pulse (EMP) attacks, which can be extremely harmful...

Currently, we observe a high popularity of the traffic-aware network management and optimization approaches, which benefit from the traffic modeling and prediction tools. The efficiency of these approaches depends on the accuracy of the applied modeling and prediction methods, which might be significantly decreased by exceptional events and anomali...

In this paper, we focus on the efficient dynamic routing in Spectrally-Spatially Flexible Optical Networks (ss-fon) realized using Single-Mode Fiber Bundles (smfbs). We study two scenarios – unprotected network (np) and network protected by dedicated path protection (dpp) against a single link failure. For these configurations, we propose a dedicat...

Adapting to concept drift is a challenging task in machine learning, which is usually tackled using incremental learning techniques that periodically re-fit a learning model leveraging newly available data. A primary limitation of these techniques is their reliance on substantial amounts of data for retraining. The necessity of acquiring fresh data...

Knowledge about the future link load is an essential issue for optical network operators, especially in the case of network failure and the restoration of affected traffic. In this paper, we study the dynamic operation of an optical network in its normal non-failure state and the situation of a link failure followed by the restoration process. Data...

The latest trends in computer networks bring new challenges and complex optimization problems, one of which is link dimensioning in Spectrally-Spatially Flexible Optical Networks. The time-consuming calculations related to determining the objective function representing the amount of accepted traffic require heuristics to search for good quality so...

In Elastic Optical Networks (EONs), the way different service demands are supported in the network is ruled by the Routing, Modulation and Spectrum Assignment (RMSA) algorithm, which decides how the spectrum resources of the optical network are assigned to each service demand. In a dynamic EON, demand requests arrive randomly one at a time and the...

Traffic in current networks is constantly increasing due to the growing popularity of various network services. The currently deployed backbone optical networks apply wavelength division multiplexing (WDM) techniques in single-core single-mode fibers (SMFs) to transmit the light. However, the capacity of SMFs is limited due to physical constraints,...

In this paper, we study problem of efficient service relocation (i.e., changing assigned data center for a selected client node) in elastic optical networks (EONs) in order to increase network performance (measured by the volume of accepted traffic). To this end, we first propose novel traffic model for cloud ready transport networks. The model tak...

The telecommunication networks have become an indispensable part of our everyday life, providing support for such important areas as business, education, health care, finances, entertainment and social life. Alongside their continuous and uninterrupted operation is required while numerous new threats and attack scenarios emerge. The international s...

Due to the continuous growth of Internet traffic, new technologies are proposed to overcome the capacity crunch problem. One of the most promising solutions for optical backbone networks is space division multiplexing (SDM), which allows parallel transmissions in properly designed optical fibers. In SDM, the problem of routing, space, and spectrum...

Optical networks are vital communication infrastructure that supports services critical for the functioning of information society. The continuous growth of network traffic with tightening performance requirements combined with evolving physical-layer security threats poses multi-faceted challenges for network operators. To reduce network exposure...

The following paper considers pattern recognition-aided optimization of complex and relevant problem related to optical networks. For that problem, we propose a four-step dedicated optimization approach that makes use, among others, of a regression method. The main focus of that study is put on the construction of efficient regression model and its...

This article identifies the unavoidably required upgrade of short-term realizable elastic optical networks (EONs) operating over single-mode fibers toward spectrally-spatially flexible optical networks (SS-FONs), exploiting spatial division multiplexing (SDM) technology in order to cope with the expected mid- and long-term future traffic forecasts....

We focus on spectrally-spatially flexible optical networks and analyze benefits of adjusting the number of active spatial modes in network links using various metrics based on data analytics with the goal to maximize the served traffic.

Optimization of lightpath provisioning in a spectrally-spatially flexible optical network (SS-FON) is challenging due to many difficult constraints that exist in optical networks and because of limited amounts of various transmission resources (such as spectrum, spatial modes, transceivers, regeneration points). Previously demonstrated approaches u...

Spectrally-spatially flexible optical networks (SS-FONs) are proposed as a solution to overcome the expected capacity crunch caused by the rapidly growing overall Internet traffic. SS-FONs combine two network technologies, namely, flex-grid optical networks and spatial division multiplexing yielding a significant capacity increase. Moreover, networ...

Multi-population approach, also known as Island Model (IM), is a well-known technique improving diversity preservation. It is employed by evolutionary and Swarm Intelligence methods. The diversity increased through the maintenance of many subpopulations, leads to finding higher quality solutions. Since IM is computationally expensive, it is importa...

The paper investigates efficient allocation of three types of flows (unicast, anycast, multicast) in elastic optical network with dedicated path protection. We model the problem as an integer linear programming and propose efficient solution methods: greedy randomized algorithm (GRA) and column generation (CG)-based approach implemented in two vers...

In this paper we study important and weakly-investigated optimization problem imposed by the fast telecommunication networks development. The problem concerns routing of three types of flows (unicast, anycast, multicast) in survivable Elastic Optical Network (EON). Three types of flows allow to efficiently support cloud-related services while netwo...

Space Division Multiplexing (SDM) is a promising solution to provide ultra-high capacity optical network infrastructure for rapidly increasing traffic demands. Such network infrastructure can be a target of deliberate attacks that aim at disrupting a large number of vital services. This paper assesses the effects of high-power jamming attacks in SD...

Contemporary society relies on fast and reliable transfer of information, leading to ever-increasing size of transmitted data that stimulates the development of new algorithms for network management and optimization. This paper covers problem of allocating three types of network flows (unicast, anycast, multicast) in elastic optical network that im...

In this paper, we focus on the performance of a survivable flex-grid network with space division multiplexing (SDM). To provide network survivability, we use dedicated path protection (DPP) and shared backup path protection (SBPP). For both schemes, we consider also squeezed protection that allocates backup resources only for a part of the primary...

Driven by increasing user requirements and expectations, the fast development of telecommunications networks brings new challenging optimization problems. One of them is routing and spectrum allocation (RSA) of three types of network flows (unicast, anycast, multicast) in elastic optical networks (EONs) implementing dedicated path protection (DPP)....

The paper investigates a problem of allocating three types of flows (unicast, anycast, multicast) in elastic optical network (EON) with dedicated path protection (DPP). We model the problem using integer linear programming (ILP) and propose solution methods: two greedy algorithms and column generation (CG)-based approach. The main paper focus is pu...

In this paper, we address the problem of routing, space and spectrum assignment (RSSA) in survivable flex-grid networks that implement spatial division multiplexing (SDM). In our consideration, we focus on two switching policies for the SDM (namely, independent and joint) while the network survivability is provided by dedicated path protection (DPP...

In this paper, we focus on efficient column generation (CG)-based method for routing and spectrum allocation (RSA) of anycast traffic in survivable elastic optical networks (EONs). The studied anycast traffic is modelled as a two-directional transmission (from the client node to a data center and from a data center to the client) while the network...

The ongoing transition towards a networked society requires reliable and secure network infrastructure and services. As networks evolve from simple point to point systems towards complex, software-defined, ultra-high capacity and reach, and distributed cloud environments, new security challenges emerge. The EU-funded RECODIS project aims at coordin...

In this paper, we focus on the routing and spectrum allocation (RSA) problem in survivable elastic optical networks (EONs) with unicast and anycast traffic demands. We study a number of problem versions which differ in the involved technological constraints and facilities entailed by the EON technology, as well as, in the applied protection scheme,...

Elastic optical network (EON) is a technology that supports high bit-rate traffic demands in more efficient way comparing to traditional wavelength division multiplexing (WDM) optical networks. To facilitate the process of large content delivery in EONs, multicasting and anycasting transmission techniques can be applied instead of a simple unicast...

In this paper, an optimization problem in elastic optical networks (EONs) is considered. The problem concerns routing and spectrum allocation with joint optimization of anycast and unicast demands protected by dedicated optical paths. A new integer linear programming (ILP) problem formulation is presented, which aims at overcoming scalability probl...

In this paper, we focus on the problem of locating data centers (DCs) and routing traffic demands in survivable elastic optical network (EON). We consider and compare two different modeling and optimization approaches: joint optimization of both issues at the same time (problem DC-RSA) and decomposition method, which divides problem into two subseq...

In this paper, we focus on the survivability of elastic optical networks (EONs) that jointly support two types of traffic demands: unicast and anycast. To provide network survivability, we apply multipath routing; i.e., we allow the splitting of a demand into a number of routing paths if the paths’ combination guarantees the realization of a specif...

The following two books are reviewed: Nature-Inspired Optimization Algorithms (Xin-She Yang; 2014); and Secure Messaging on the Internet (Oppliger, R.; 2014)

In this article, we analyze gains resulting from the use of elastic optical network (EON) architectures with special focus on transportation of cloud-ready and content-oriented traffic in the context of network resilience. EONs are a promising approach for future optical transport networks and, apart from improving the network spectral efficiency,...

In this paper, we focus on the important problem of locating data centers (DCs) in elastic optical network (EON). We propose to use both topology-based (that follow directly from the network graph structure) and demographic-economical (characteristics of the cities that correspond to network nodes) data to define DC location policies. In particular...

Nowadays, multicasting is increasingly popular, due to the ability to provision in efficient way such desirable services like streaming, IP television, software distribution, etc. At the same time, the research in the field of optical networks concentrates on the very promising elastic optical networks (EONs) approach. In this paper, we focus on th...

The fast social and economic development observed in the recent years brings up new challenging optimization problems. These problems are often very hard not only because of their computational complexity, but also due to their enormous solution space size. Therefore, this paper proposes an effective optimization method, based on the novel Multi Po...

In this paper, an optimization problem in elastic optical networks (EONs) is considered. The problem concerns routing and spectrum allocation with joint optimization of anycast and unicast demands protected by dedicated optical paths. A new integer linear programming (ILP) problem formulation is presented, which aims at overcoming scalability probl...

The impact of traffic asymmetry on performance of Elastic Optical Networks (EONs) is studied. Results of experiments are presented to show how both symmetric and asymmetric lightpath provisioning scenarios influence spectrum usage and network CAPEX cost.

The paper presents a novel method based on the standard tabu search (TS) approach, dedicated to solve the routing, modulation and spectrum allocation (RMSA) problem in elastic optical networks (EONs). The considered formulation of the RMSA problem covers simultaneously unicast (one-to-one) and anycast (one-to-one-of-many) traffic demands. This is a...

The impact of fanout and transmission reach on provisioning of static multicast traffic in Elastic Optical Networks is studied. Result of numerical experiments are presented to show the impact in terms of spectrum and regenerator usage.1.

In this paper, the problem of routing multicast demands in elastic optical network (EON) is studied. In order to solve the problem in an efficient way, the tabu search algorithm with move prioritization mechanism is proposed. The algorithm is considered in 4 versions, which differ in the move generation process. Next, the numerical experiments are...

The adoption of a flexible grid will benefit the network design and control plane of future optical networks by providing increased adaptability of spectral resources to heterogeneous network conditions. Unfortunately, this flexibility is gained at the cost of significant additional complexity in the network design and control. In this paper, we co...

In this letter, we propose three new approaches to optimizing multicast traffic in Elastic Optical Networks (EONs) that implement distance-adaptive transmission. Two of the approaches are based on Integer Linear Programming (ILP) modeling, while the last one is an effective heuristic. We also compare our approaches with reference methods proposed i...

Recently, the Content Oriented Networking (CON) has become a recognized approach that is gaining extensive acceptance and deployment. At the same time, Elastic Optical Networks (EONs) are considered as a very promising approach for effective bandwidth allocation in optical networks. In this paper, we consider various approaches to content distribut...

In this paper, we focus on a survivable elastic optical network (EON) that supports both unicast and anycast traffic demands. The network implements a dedicated path protection scheme (DPP), in which backup lightpaths are assigned to traffic demands so that to protect against single link failures. In a normal network state, each anycast demand is s...

The paper examines several content distribution scenarios in Elastic Optical Networks (EONs). Numerical experiments are presented to verify the proposed approaches and compare EONs against classical Wavelength Switched Optical Networks (WSONs) in terms of various performance metrics including spectrum, cost and power consumption.

In this paper, we focus on cloud-ready elastic optical network with distance-adaptive transponders. We analyze the trade-off between number of required regenerators and spectrum usage for a US backbone network with traffic patterns based on Cisco predictions.

The impact of traffic asymmetry on usage of multiflow transponders (MFTs) in elastic optical networks with dedicated path protection is examined. Based on experiments performed on European network, acceptable costs of MFTs, with respect to 100G WDM transponders, are evaluated. Introduction The multiflow transponder (MFT), known also as Sliceable Ba...

In this paper, we analyze distance-adaptive transmission in cloud-ready elastic optical networks (EONs). To this end, we focus on the routing, modulation, and spectrum allocation problem, which we formulate as an integer linear programming problem, taking into account such optimization criteria (network performance metrics) as network capital expen...

In this paper we present a tabu search-based algorithm, which is dedicated to solving the routing and spectrum allocation problem in elastic optical networks. To evaluate performance of the proposed method, we carry a number of experiments on realistic network topologies. We compare our method with both optimal results yielded by the CPLEX solver a...

Elastic Optical Network (EON) architectures have been recently proposed as a candidate solution for provisioning of both huge bandwidth and flexible connections in next generation optical networks. In this article, we focus on survivable EON scenarios and, in particular, we address an offline problem of routing and spectrum allocation (RSA) with de...

Elastic optical network (EON) architectures are considered as a very promising approach for future optical transport networks, since they efficiently use the spectrum resources and provide high bandwidth scalability and granularity. At the same time, the multicast transmission technique is widely used to provide increasingly popular streaming servi...

Elastic Optical Networks (EONs) are considered as a very promising approach for effective bandwidth allocation in optical networks. Concurrently, anycast (one-to-one-of-many transmission technique) is gaining more and more interest in contemporary Internet due to its connection with as popular services as Content Delivery Networks, video streaming,...

The paper proposes a Tabu Search algorithm for Routing and Spectrum Allocation with joint unicast and anycast traffic in Elastic Optical Networks (EONs). Numerical experiments are presented to verify the algorithm and show main features of EONs with anycast traffic.

Modern optical networks must meet many challenges following from the quick and permanent development of IT industry. The latest trend that focuses much attention is cloud computing -- a concept that enables delivery of various IT services over the Internet. From the network perspective, the cloud computing implies a growth of the traffic volume and...

This paper presents final results of investigation focused on modelling computer networks– a very important issue affecting Wide Area Networks nowadays. Modelling computer networks includes two main groups of problems: optimization of existing topologies and new topology design. In this paper we formulate FA and CFA problems for WAN and propose nov...